package com.fasterxml.jackson.databind;

import java.io.*;
import java.net.URL;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.filter.FilteringParserDelegate;
import com.fasterxml.jackson.core.filter.JsonPointerBasedFilter;
import com.fasterxml.jackson.core.filter.TokenFilter;
import com.fasterxml.jackson.core.type.ResolvedType;
import com.fasterxml.jackson.core.type.TypeReference;

import com.fasterxml.jackson.databind.cfg.ContextAttributes;
import com.fasterxml.jackson.databind.deser.DataFormatReaders;
import com.fasterxml.jackson.databind.deser.DefaultDeserializationContext;
import com.fasterxml.jackson.databind.deser.DeserializationProblemHandler;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.fasterxml.jackson.databind.node.TreeTraversingParser;
import com.fasterxml.jackson.databind.type.SimpleType;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.fasterxml.jackson.databind.util.ClassUtil;

Builder object that can be used for per-serialization configuration of
deserialization parameters, such as root type to use or object
to update (instead of constructing new instance).
 Uses "mutant factory" pattern so that instances are immutable (and thus fully thread-safe with no external synchronization); new instances are constructed for different configurations. Instances are initially constructed by ObjectMapper and can be reused, shared, cached; both because of thread-safety and because instances are relatively light-weight. 

NOTE: this class is NOT meant as sub-classable (with Jackson 2.8 and
above) by users. It is left as non-final mostly to allow frameworks
that require bytecode generation for proxying and similar use cases,
but there is no expecation that functionality should be extended
by sub-classing.
/**
 * Builder object that can be used for per-serialization configuration of
 * deserialization parameters, such as root type to use or object
 * to update (instead of constructing new instance).
 *<p>
 * Uses "mutant factory" pattern so that instances are immutable
 * (and thus fully thread-safe with no external synchronization);
 * new instances are constructed for different configurations.
 * Instances are initially constructed by {@link ObjectMapper} and can be
 * reused, shared, cached; both because of thread-safety and because
 * instances are relatively light-weight.
 *<p>
 * NOTE: this class is NOT meant as sub-classable (with Jackson 2.8 and
 * above) by users. It is left as non-final mostly to allow frameworks
 * that require bytecode generation for proxying and similar use cases,
 * but there is no expecation that functionality should be extended
 * by sub-classing.
 */
public class ObjectReader
    extends ObjectCodec
    implements Versioned, java.io.Serializable // since 2.1
{
    private static final long serialVersionUID = 2L; // since 2.9

    private final static JavaType JSON_NODE_TYPE = SimpleType.constructUnsafe(JsonNode.class);

    /*
    /**********************************************************
    /* Immutable configuration from ObjectMapper
    /**********************************************************
     */

    
General serialization configuration settings; while immutable,
can use copy-constructor to create modified instances as necessary.
/**
     * General serialization configuration settings; while immutable,
     * can use copy-constructor to create modified instances as necessary.
     */
    protected final DeserializationConfig _config;

    
Blueprint instance of deserialization context; used for creating
actual instance when needed.
/**
     * Blueprint instance of deserialization context; used for creating
     * actual instance when needed.
     */
    protected final DefaultDeserializationContext _context;

    
Factory used for constructing JsonGenerators /**
     * Factory used for constructing {@link JsonGenerator}s
     */
    protected final JsonFactory _parserFactory;

    
Flag that indicates whether root values are expected to be unwrapped or not
/**
     * Flag that indicates whether root values are expected to be unwrapped or not
     */
    protected final boolean _unwrapRoot;

    
Filter to be consider for JsonParser.  
Default value to be null as filter not considered.
/**
     * Filter to be consider for JsonParser.  
     * Default value to be null as filter not considered.
     */
    private final TokenFilter _filter;
    
    /*
    /**********************************************************
    /* Configuration that can be changed during building
    /**********************************************************
     */

    
Declared type of value to instantiate during deserialization. Defines which deserializer to use; as well as base type of instance to construct if an updatable value is not configured to be used (subject to changes by embedded type information, for polymorphic types). If _valueToUpdate is non-null, only used for locating deserializer. /**
     * Declared type of value to instantiate during deserialization.
     * Defines which deserializer to use; as well as base type of instance
     * to construct if an updatable value is not configured to be used
     * (subject to changes by embedded type information, for polymorphic
     * types). If {@link #_valueToUpdate} is non-null, only used for
     * locating deserializer.
     */
    protected final JavaType _valueType;

    
We may pre-fetch deserializer as soon as _valueType is known, and if so, reuse it afterwards. This allows avoiding further deserializer lookups and increases performance a bit on cases where readers are reused. 
Since:
2.1/**
     * We may pre-fetch deserializer as soon as {@link #_valueType}
     * is known, and if so, reuse it afterwards.
     * This allows avoiding further deserializer lookups and increases
     * performance a bit on cases where readers are reused.
     * 
     * @since 2.1
     */
    protected final JsonDeserializer<Object> _rootDeserializer;
    
    
Instance to update with data binding; if any. If null, a new instance is created, if non-null, properties of this value object will be updated instead. Note that value can be of almost any type, except not ArrayType; array types cannot be modified because array size is immutable. /**
     * Instance to update with data binding; if any. If null,
     * a new instance is created, if non-null, properties of
     * this value object will be updated instead.
     * Note that value can be of almost any type, except not
     * {@link com.fasterxml.jackson.databind.type.ArrayType}; array
     * types cannot be modified because array size is immutable.
     */
    protected final Object _valueToUpdate;

    
When using data format that uses a schema, schema is passed
to parser.
/**
     * When using data format that uses a schema, schema is passed
     * to parser.
     */
    protected final FormatSchema _schema;

    
Values that can be injected during deserialization, if any.
/**
     * Values that can be injected during deserialization, if any.
     */
    protected final InjectableValues _injectableValues;

    
Optional detector used for auto-detecting data format that byte-based
input uses.

NOTE: If defined non-null, readValue() methods that take Reader or String input will fail with exception, because format-detection only works on byte-sources. Also, if format cannot be detect reliably (as per detector settings), a JsonParseException will be thrown). 
Since:
2.1/**
     * Optional detector used for auto-detecting data format that byte-based
     * input uses.
     *<p>
     * NOTE: If defined non-null, <code>readValue()</code> methods that take
     * {@link Reader} or {@link String} input <b>will fail with exception</b>,
     * because format-detection only works on byte-sources. Also, if format
     * cannot be detect reliably (as per detector settings),
     * a {@link JsonParseException} will be thrown).
     * 
     * @since 2.1
     */
    protected final DataFormatReaders _dataFormatReaders;

    /*
    /**********************************************************
    /* Caching
    /**********************************************************
     */

    
Root-level cached deserializers. Passed by ObjectMapper, shared with it. /**
     * Root-level cached deserializers.
     * Passed by {@link ObjectMapper}, shared with it.
     */
    final protected ConcurrentHashMap<JavaType, JsonDeserializer<Object>> _rootDeserializers;

    /*
    /**********************************************************
    /* Life-cycle, construction
    /**********************************************************
     */

    
Constructor used by ObjectMapper for initial instantiation /**
     * Constructor used by {@link ObjectMapper} for initial instantiation
     */
    protected ObjectReader(ObjectMapper mapper, DeserializationConfig config) {
        this(mapper, config, null, null, null, null);
    }

    
Constructor called when a root deserializer should be fetched based
on other configuration.
/**
     * Constructor called when a root deserializer should be fetched based
     * on other configuration.
     */
    protected ObjectReader(ObjectMapper mapper, DeserializationConfig config,
            JavaType valueType, Object valueToUpdate,
            FormatSchema schema, InjectableValues injectableValues)
    {
        _config = config;
        _context = mapper._deserializationContext;
        _rootDeserializers = mapper._rootDeserializers;
        _parserFactory = mapper._jsonFactory;
        _valueType = valueType;
        _valueToUpdate = valueToUpdate;
        _schema = schema;
        _injectableValues = injectableValues;
        _unwrapRoot = config.useRootWrapping();

        _rootDeserializer = _prefetchRootDeserializer(valueType);
        _dataFormatReaders = null;        
        _filter = null;
    }
    
    
Copy constructor used for building variations.
/**
     * Copy constructor used for building variations.
     */
    protected ObjectReader(ObjectReader base, DeserializationConfig config,
            JavaType valueType, JsonDeserializer<Object> rootDeser, Object valueToUpdate,
            FormatSchema schema, InjectableValues injectableValues,
            DataFormatReaders dataFormatReaders)
    {
        _config = config;
        _context = base._context;

        _rootDeserializers = base._rootDeserializers;
        _parserFactory = base._parserFactory;

        _valueType = valueType;
        _rootDeserializer = rootDeser;
        _valueToUpdate = valueToUpdate;
        _schema = schema;
        _injectableValues = injectableValues;
        _unwrapRoot = config.useRootWrapping();
        _dataFormatReaders = dataFormatReaders;
        _filter = base._filter;
    }

    
Copy constructor used when modifying simple feature flags
/**
     * Copy constructor used when modifying simple feature flags
     */
    protected ObjectReader(ObjectReader base, DeserializationConfig config)
    {
        _config = config;
        _context = base._context;

        _rootDeserializers = base._rootDeserializers;
        _parserFactory = base._parserFactory;

        _valueType = base._valueType;
        _rootDeserializer = base._rootDeserializer;
        _valueToUpdate = base._valueToUpdate;
        _schema = base._schema;
        _injectableValues = base._injectableValues;
        _unwrapRoot = config.useRootWrapping();
        _dataFormatReaders = base._dataFormatReaders;
        _filter = base._filter;
    }
    
    protected ObjectReader(ObjectReader base, JsonFactory f)
    {
        // may need to override ordering, based on data format capabilities
        _config = base._config
            .with(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY, f.requiresPropertyOrdering());
        _context = base._context;

        _rootDeserializers = base._rootDeserializers;
        _parserFactory = f;

        _valueType = base._valueType;
        _rootDeserializer = base._rootDeserializer;
        _valueToUpdate = base._valueToUpdate;
        _schema = base._schema;
        _injectableValues = base._injectableValues;
        _unwrapRoot = base._unwrapRoot;
        _dataFormatReaders = base._dataFormatReaders;
        _filter = base._filter;
    }
    
    protected ObjectReader(ObjectReader base, TokenFilter filter) {
        _config = base._config;
        _context = base._context;
        _rootDeserializers = base._rootDeserializers;
        _parserFactory = base._parserFactory;
        _valueType = base._valueType;
        _rootDeserializer = base._rootDeserializer;
        _valueToUpdate = base._valueToUpdate;
        _schema = base._schema;
        _injectableValues = base._injectableValues;
        _unwrapRoot = base._unwrapRoot;
        _dataFormatReaders = base._dataFormatReaders;
        _filter = filter;
    }
    
    
Method that will return version information stored in and read from jar
that contains this class.
/**
     * Method that will return version information stored in and read from jar
     * that contains this class.
     */
    @Override
    public Version version() {
        return com.fasterxml.jackson.databind.cfg.PackageVersion.VERSION;
    }

    /*
    /**********************************************************
    /* Helper methods used internally for invoking constructors
    /* Need to be overridden if sub-classing (not recommended)
    /* is used.
    /**********************************************************
     */

    
Overridable factory method called by various "withXxx()" methods
Since:
2.5/**
     * Overridable factory method called by various "withXxx()" methods
     * 
     * @since 2.5
     */
    protected ObjectReader _new(ObjectReader base, JsonFactory f) {
        return new ObjectReader(base, f);
    }

    
Overridable factory method called by various "withXxx()" methods
Since:
2.5/**
     * Overridable factory method called by various "withXxx()" methods
     * 
     * @since 2.5
     */
    protected ObjectReader _new(ObjectReader base, DeserializationConfig config) {
        return new ObjectReader(base, config);
    }

    
Overridable factory method called by various "withXxx()" methods
Since:
2.5/**
     * Overridable factory method called by various "withXxx()" methods
     * 
     * @since 2.5
     */
    protected ObjectReader _new(ObjectReader base, DeserializationConfig config,
            JavaType valueType, JsonDeserializer<Object> rootDeser, Object valueToUpdate,
            FormatSchema schema, InjectableValues injectableValues,
            DataFormatReaders dataFormatReaders) {
        return new ObjectReader(base, config, valueType, rootDeser,  valueToUpdate,
                 schema,  injectableValues, dataFormatReaders);
    }

    
Factory method used to create MappingIterator instances; either default, or custom subtype. 
Since:
2.5/**
     * Factory method used to create {@link MappingIterator} instances;
     * either default, or custom subtype.
     * 
     * @since 2.5
     */
    protected <T> MappingIterator<T> _newIterator(JsonParser p, DeserializationContext ctxt,
            JsonDeserializer<?> deser, boolean parserManaged)
    {
        return new MappingIterator<T>(_valueType, p, ctxt,
                deser, parserManaged, _valueToUpdate);
    }

    /*
    /**********************************************************
    /* Methods for initializing parser instance to use
    /**********************************************************
     */

    protected JsonToken _initForReading(DeserializationContext ctxt, JsonParser p)
        throws IOException
    {
        if (_schema != null) {
            p.setSchema(_schema);
        }
        _config.initialize(p); // since 2.5

        /* First: must point to a token; if not pointing to one, advance.
         * This occurs before first read from JsonParser, as well as
         * after clearing of current token.
         */
        JsonToken t = p.getCurrentToken();
        if (t == null) { // and then we must get something...
            t = p.nextToken();
            if (t == null) {
                // Throw mapping exception, since it's failure to map, not an actual parsing problem
                ctxt.reportInputMismatch(_valueType,
                        "No content to map due to end-of-input");
            }
        }
        return t;
    }

    
Alternative to _initForReading used in cases where reading of multiple values means that we may or may not want to advance the stream, but need to do other initialization. 
 Base implementation only sets configured FormatSchema, if any, on parser. 
Since:
2.8/**
     * Alternative to {@link #_initForReading} used in cases where reading
     * of multiple values means that we may or may not want to advance the stream,
     * but need to do other initialization.
     *<p>
     * Base implementation only sets configured {@link FormatSchema}, if any, on parser.
     * 
     * @since 2.8
     */
    protected void _initForMultiRead(DeserializationContext ctxt, JsonParser p)
        throws IOException
    {
        if (_schema != null) {
            p.setSchema(_schema);
        }
        _config.initialize(p);
    }

    /*
    /**********************************************************
    /* Life-cycle, fluent factory methods for DeserializationFeatures
    /**********************************************************
     */

    
Method for constructing a new reader instance that is configured
with specified feature enabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified feature enabled.
     */
    public ObjectReader with(DeserializationFeature feature) {
        return _with(_config.with(feature));
    }

    
Method for constructing a new reader instance that is configured
with specified features enabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features enabled.
     */
    public ObjectReader with(DeserializationFeature first,
            DeserializationFeature... other)
    {
        return _with(_config.with(first, other));
    }    

    
Method for constructing a new reader instance that is configured
with specified features enabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features enabled.
     */
    public ObjectReader withFeatures(DeserializationFeature... features) {
        return _with(_config.withFeatures(features));
    }    

    
Method for constructing a new reader instance that is configured
with specified feature disabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified feature disabled.
     */
    public ObjectReader without(DeserializationFeature feature) {
        return _with(_config.without(feature)); 
    }

    
Method for constructing a new reader instance that is configured
with specified features disabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features disabled.
     */
    public ObjectReader without(DeserializationFeature first,
            DeserializationFeature... other) {
        return _with(_config.without(first, other));
    }    

    
Method for constructing a new reader instance that is configured
with specified features disabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features disabled.
     */
    public ObjectReader withoutFeatures(DeserializationFeature... features) {
        return _with(_config.withoutFeatures(features));
    }    

    /*
    /**********************************************************
    /* Life-cycle, fluent factory methods for JsonParser.Features
    /**********************************************************
     */

    
Method for constructing a new reader instance that is configured
with specified feature enabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified feature enabled.
     */
    public ObjectReader with(JsonParser.Feature feature) {
        return _with(_config.with(feature));
    }

    
Method for constructing a new reader instance that is configured
with specified features enabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features enabled.
     */
    public ObjectReader withFeatures(JsonParser.Feature... features) {
        return _with(_config.withFeatures(features));
    }    

    
Method for constructing a new reader instance that is configured
with specified feature disabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified feature disabled.
     */
    public ObjectReader without(JsonParser.Feature feature) {
        return _with(_config.without(feature)); 
    }

    
Method for constructing a new reader instance that is configured
with specified features disabled.
/**
     * Method for constructing a new reader instance that is configured
     * with specified features disabled.
     */
    public ObjectReader withoutFeatures(JsonParser.Feature... features) {
        return _with(_config.withoutFeatures(features));
    }

    /*
    /**********************************************************
    /* Life-cycle, fluent factory methods for FormatFeature (2.7)
    /**********************************************************
     */

    
Method for constructing a new reader instance that is configured
with specified feature enabled.
Since:
2.7/**
     * Method for constructing a new reader instance that is configured
     * with specified feature enabled.
     *
     * @since 2.7
     */
    public ObjectReader with(FormatFeature feature) {
        return _with(_config.with(feature));
    }

    
Method for constructing a new reader instance that is configured
with specified features enabled.
Since:
2.7/**
     * Method for constructing a new reader instance that is configured
     * with specified features enabled.
     *
     * @since 2.7
     */
    public ObjectReader withFeatures(FormatFeature... features) {
        return _with(_config.withFeatures(features));
    }    

    
Method for constructing a new reader instance that is configured
with specified feature disabled.
Since:
2.7/**
     * Method for constructing a new reader instance that is configured
     * with specified feature disabled.
     *
     * @since 2.7
     */
    public ObjectReader without(FormatFeature feature) {
        return _with(_config.without(feature)); 
    }

    
Method for constructing a new reader instance that is configured
with specified features disabled.
Since:
2.7/**
     * Method for constructing a new reader instance that is configured
     * with specified features disabled.
     *
     * @since 2.7
     */
    public ObjectReader withoutFeatures(FormatFeature... features) {
        return _with(_config.withoutFeatures(features));
    }
    
    /*
    /**********************************************************
    /* Life-cycle, fluent factory methods, other
    /**********************************************************
     */

    
Convenience method to bind from JsonPointer. JsonPointerBasedFilter is registered and will be used for parsing later. 
Since:
2.6/**
     * Convenience method to bind from {@link JsonPointer}.  
     * {@link JsonPointerBasedFilter} is registered and will be used for parsing later. 
     * @since 2.6
     */
    public ObjectReader at(final String value) {
        return new ObjectReader(this, new JsonPointerBasedFilter(value));
    }

    
Convenience method to bind from JsonPointer JsonPointerBasedFilter is registered and will be used for parsing later. 
Since:
2.6/**
     * Convenience method to bind from {@link JsonPointer}
      * {@link JsonPointerBasedFilter} is registered and will be used for parsing later.
     * @since 2.6
     */
    public ObjectReader at(final JsonPointer pointer) {
        return new ObjectReader(this, new JsonPointerBasedFilter(pointer));
    }

    
Mutant factory method that will construct a new instance that has specified underlying DeserializationConfig. 

NOTE: use of this method is not recommended, as there are many other
re-configuration methods available.
/**
     * Mutant factory method that will construct a new instance that has
     * specified underlying {@link DeserializationConfig}.
     *<p>
     * NOTE: use of this method is not recommended, as there are many other
     * re-configuration methods available.
     */
    public ObjectReader with(DeserializationConfig config) {
        return _with(config);
    }    

    
Method for constructing a new instance with configuration that uses passed InjectableValues to provide injectable values. 

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new instance with configuration that uses
     * passed {@link InjectableValues} to provide injectable values.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader with(InjectableValues injectableValues)
    {
        if (_injectableValues == injectableValues) {
            return this;
        }
        return _new(this, _config,
                _valueType, _rootDeserializer, _valueToUpdate,
                _schema, injectableValues, _dataFormatReaders);
    }

    
Method for constructing a new reader instance with configuration that uses passed JsonNodeFactory for constructing JsonNode instances. 

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new reader instance with configuration that uses
     * passed {@link JsonNodeFactory} for constructing {@link JsonNode}
     * instances.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader with(JsonNodeFactory f) {
        return _with(_config.with(f));
    }

    
Method for constructing a new reader instance with configuration that uses passed JsonFactory for constructing underlying Readers. 

NOTE: only factories that DO NOT REQUIRE SPECIAL MAPPERS
(that is, ones that return false for JsonFactory.requiresCustomCodec()) can be used: trying to use one that requires custom codec will throw exception 
Since:
2.1/**
     * Method for constructing a new reader instance with configuration that uses
     * passed {@link JsonFactory} for constructing underlying Readers.
     *<p>
     * NOTE: only factories that <b>DO NOT REQUIRE SPECIAL MAPPERS</b>
     * (that is, ones that return <code>false</code> for
     * {@link JsonFactory#requiresCustomCodec()}) can be used: trying
     * to use one that requires custom codec will throw exception
     * 
     * @since 2.1
     */
    public ObjectReader with(JsonFactory f) {
        if (f == _parserFactory) {
            return this;
        }
        ObjectReader r = _new(this, f);
        // Also, try re-linking, if possible...
        if (f.getCodec() == null) {
            f.setCodec(r);
        }
        return r;
    }
    
    
Method for constructing a new instance with configuration that specifies what root name to expect for "root name unwrapping". See MapperConfigBase<DeserializationFeature,DeserializationConfig>.withRootName(String) for details. 

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new instance with configuration that
     * specifies what root name to expect for "root name unwrapping".
     * See {@link DeserializationConfig#withRootName(String)} for
     * details.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader withRootName(String rootName) {
        return _with(_config.withRootName(rootName));
    }

    
Since:
2.6/**
     * @since 2.6
     */
    public ObjectReader withRootName(PropertyName rootName) {
        return _with(_config.withRootName(rootName));
    }
    
    
Convenience method that is same as calling:

  withRootName("")
 which will forcibly prevent use of root name wrapping when writing values with this ObjectReader. 
Since:
2.6/**
     * Convenience method that is same as calling:
     *<code>
     *   withRootName("")
     *</code>
     * which will forcibly prevent use of root name wrapping when writing
     * values with this {@link ObjectReader}.
     * 
     * @since 2.6
     */
    public ObjectReader withoutRootName() {
        return _with(_config.withRootName(PropertyName.NO_NAME));
    }
    
    
Method for constructing a new instance with configuration that passes specified FormatSchema to JsonParser that is constructed for parsing content. 

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new instance with configuration that
     * passes specified {@link FormatSchema} to {@link JsonParser} that
     * is constructed for parsing content.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader with(FormatSchema schema)
    {
        if (_schema == schema) {
            return this;
        }
        _verifySchemaType(schema);
        return _new(this, _config, _valueType, _rootDeserializer, _valueToUpdate,
                schema, _injectableValues, _dataFormatReaders);
    }

    
Method for constructing a new reader instance that is configured
to data bind into specified type.

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
Since:
2.5/**
     * Method for constructing a new reader instance that is configured
     * to data bind into specified type.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     * 
     * @since 2.5
     */
    public ObjectReader forType(JavaType valueType)
    {
        if (valueType != null && valueType.equals(_valueType)) {
            return this;
        }
        JsonDeserializer<Object> rootDeser = _prefetchRootDeserializer(valueType);
        // type is stored here, no need to make a copy of config
        DataFormatReaders det = _dataFormatReaders;
        if (det != null) {
            det = det.withType(valueType);
        }
        return _new(this, _config, valueType, rootDeser,
                _valueToUpdate, _schema, _injectableValues, det);
    }    

    
Method for constructing a new reader instance that is configured
to data bind into specified type.

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
Since:
2.5/**
     * Method for constructing a new reader instance that is configured
     * to data bind into specified type.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     *
     * @since 2.5
     */
    public ObjectReader forType(Class<?> valueType) {
        return forType(_config.constructType(valueType));
    }    

    
Method for constructing a new reader instance that is configured
to data bind into specified type.

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
Since:
2.5/**
     * Method for constructing a new reader instance that is configured
     * to data bind into specified type.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     *
     * @since 2.5
     */
    public ObjectReader forType(TypeReference<?> valueTypeRef) {
        return forType(_config.getTypeFactory().constructType(valueTypeRef.getType()));
    }    

    
Deprecated:
since 2.5 Use forType(JavaType) instead/**
     * @deprecated since 2.5 Use {@link #forType(JavaType)} instead
     */
    @Deprecated
    public ObjectReader withType(JavaType valueType) {
        return forType(valueType);
    }

    
Deprecated:
since 2.5 Use forType(Class<?>) instead/**
     * @deprecated since 2.5 Use {@link #forType(Class)} instead
     */
    @Deprecated
    public ObjectReader withType(Class<?> valueType) {
        return forType(_config.constructType(valueType));
    }    

    
Deprecated:
since 2.5 Use forType(Class<?>) instead/**
     * @deprecated since 2.5 Use {@link #forType(Class)} instead
     */
    @Deprecated
    public ObjectReader withType(java.lang.reflect.Type valueType) {
        return forType(_config.getTypeFactory().constructType(valueType));
    }

    
Deprecated:
since 2.5 Use forType(TypeReference<?>) instead/**
     * @deprecated since 2.5 Use {@link #forType(TypeReference)} instead
     */
    @Deprecated
    public ObjectReader withType(TypeReference<?> valueTypeRef) {
        return forType(_config.getTypeFactory().constructType(valueTypeRef.getType()));
    }    

    
Method for constructing a new instance with configuration that
updates passed Object (as root value), instead of constructing 
a new value.

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new instance with configuration that
     * updates passed Object (as root value), instead of constructing 
     * a new value.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader withValueToUpdate(Object value)
    {
        if (value == _valueToUpdate) return this;
        if (value == null) {
            // 18-Oct-2016, tatu: Actually, should be allowed, to remove value
            //   to update, if any
            return _new(this, _config, _valueType, _rootDeserializer, null,
                    _schema, _injectableValues, _dataFormatReaders);
        }
        JavaType t;
        
        /* no real benefit from pre-fetching, as updating readers are much
         * less likely to be reused, and value type may also be forced
         * with a later chained call...
         */
        if (_valueType == null) {
            t = _config.constructType(value.getClass());
        } else {
            t = _valueType;
        }
        return _new(this, _config, t, _rootDeserializer, value,
                _schema, _injectableValues, _dataFormatReaders);
    }

    
Method for constructing a new instance with configuration that
uses specified View for filtering.

Note that the method does NOT change state of this reader, but
rather construct and returns a newly configured instance.
/**
     * Method for constructing a new instance with configuration that
     * uses specified View for filtering.
     *<p>
     * Note that the method does NOT change state of this reader, but
     * rather construct and returns a newly configured instance.
     */
    public ObjectReader withView(Class<?> activeView) {
        return _with(_config.withView(activeView));
    }

    public ObjectReader with(Locale l) {
        return _with(_config.with(l));
    }

    public ObjectReader with(TimeZone tz) {
        return _with(_config.with(tz));
    }

    public ObjectReader withHandler(DeserializationProblemHandler h) {
        return _with(_config.withHandler(h));
    }

    public ObjectReader with(Base64Variant defaultBase64) {
        return _with(_config.with(defaultBase64));
    }

    
Fluent factory method for constructing a reader that will try to auto-detect underlying data format, using specified list of JsonFactory instances, and default DataFormatReaders settings (for customized DataFormatReaders, you can construct instance yourself). to construct appropriate JsonParser for actual parsing. 

Note: since format detection only works with byte sources, it is possible to
get a failure from some 'readValue()' methods. Also, if input cannot be reliably
(enough) detected as one of specified types, an exception will be thrown.
 Note: not all JsonFactory types can be passed: specifically, ones that require "custom codec" (like XML factory) will not work. Instead, use method that takes ObjectReader instances instead of factories. 
Params:
readers – Data formats accepted, in decreasing order of priority (that is,
  matches checked in listed order, first match wins)
Returns:
Newly configured writer instance
Since:
2.1/**
     * Fluent factory method for constructing a reader that will try to
     * auto-detect underlying data format, using specified list of
     * {@link JsonFactory} instances, and default {@link DataFormatReaders} settings
     * (for customized {@link DataFormatReaders}, you can construct instance yourself).
     * to construct appropriate {@link JsonParser} for actual parsing.
     *<p>
     * Note: since format detection only works with byte sources, it is possible to
     * get a failure from some 'readValue()' methods. Also, if input cannot be reliably
     * (enough) detected as one of specified types, an exception will be thrown.
     *<p>
     * Note: not all {@link JsonFactory} types can be passed: specifically, ones that
     * require "custom codec" (like XML factory) will not work. Instead, use
     * method that takes {@link ObjectReader} instances instead of factories.
     * 
     * @param readers Data formats accepted, in decreasing order of priority (that is,
     *   matches checked in listed order, first match wins)
     * 
     * @return Newly configured writer instance
     * 
     * @since 2.1
     */
    public ObjectReader withFormatDetection(ObjectReader... readers) {
        return withFormatDetection(new DataFormatReaders(readers));
    }

    
Fluent factory method for constructing a reader that will try to auto-detect underlying data format, using specified DataFormatReaders. 

NOTE: since format detection only works with byte sources, it is possible to
get a failure from some 'readValue()' methods. Also, if input cannot be reliably
(enough) detected as one of specified types, an exception will be thrown.
Params:
readers – DataFormatReaders to use for detecting underlying format.
Returns:
Newly configured writer instance
Since:
2.1/**
     * Fluent factory method for constructing a reader that will try to
     * auto-detect underlying data format, using specified
     * {@link DataFormatReaders}.
     *<p>
     * NOTE: since format detection only works with byte sources, it is possible to
     * get a failure from some 'readValue()' methods. Also, if input cannot be reliably
     * (enough) detected as one of specified types, an exception will be thrown.
     * 
     * @param readers DataFormatReaders to use for detecting underlying format.
     * 
     * @return Newly configured writer instance
     * 
     * @since 2.1
     */
    public ObjectReader withFormatDetection(DataFormatReaders readers) {
        return _new(this, _config, _valueType, _rootDeserializer, _valueToUpdate,
                _schema, _injectableValues, readers);
    }

    
Since:
2.3/**
     * @since 2.3
     */
    public ObjectReader with(ContextAttributes attrs) {
        return _with(_config.with(attrs));
    }

    
Since:
2.3/**
     * @since 2.3
     */
    public ObjectReader withAttributes(Map<?,?> attrs) {
        return _with(_config.withAttributes(attrs));
    }

    
Since:
2.3/**
     * @since 2.3
     */
    public ObjectReader withAttribute(Object key, Object value) {
        return _with( _config.withAttribute(key, value));
    }

    
Since:
2.3/**
     * @since 2.3
     */
    public ObjectReader withoutAttribute(Object key) {
        return _with(_config.withoutAttribute(key));
    }

    /*
    /**********************************************************
    /* Overridable factory methods may override
    /**********************************************************
     */
    
    protected ObjectReader _with(DeserializationConfig newConfig) {
        if (newConfig == _config) {
            return this;
        }
        ObjectReader r = _new(this, newConfig);
        if (_dataFormatReaders != null) {
            r  = r.withFormatDetection(_dataFormatReaders.with(newConfig));
        }
        return r;
    }
    
    /*
    /**********************************************************
    /* Simple accessors
    /**********************************************************
     */
    
    public boolean isEnabled(DeserializationFeature f) {
        return _config.isEnabled(f);
    }

    public boolean isEnabled(MapperFeature f) {
        return _config.isEnabled(f);
    }

    public boolean isEnabled(JsonParser.Feature f) {
        return _parserFactory.isEnabled(f);
    }

    
Since:
2.2/**
     * @since 2.2
     */
    public DeserializationConfig getConfig() {
        return _config;
    }
    
    
Since:
2.1/**
     * @since 2.1
     */
    @Override
    public JsonFactory getFactory() {
        return _parserFactory;
    }

    public TypeFactory getTypeFactory() {
        return _config.getTypeFactory();
    }

    
Since:
2.3/**
     * @since 2.3
     */
    public ContextAttributes getAttributes() {
        return _config.getAttributes();
    }

    
Since:
2.6/**
     * @since 2.6
     */
    public InjectableValues getInjectableValues() {
        return _injectableValues;
    }

    /*
    /**********************************************************
    /* Deserialization methods; basic ones to support ObjectCodec first
    /* (ones that take JsonParser)
    /**********************************************************
     */

    
Method that binds content read using given parser, using configuration of this reader, including expected result type. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Method that binds content read using given parser, using
     * configuration of this reader, including expected result type.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(JsonParser p) throws IOException
    {
        return (T) _bind(p, _valueToUpdate);
    }

    
Convenience method that binds content read using given parser, using configuration of this reader, except that expected value type is specified with the call (instead of currently configured root type). Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that binds content read using given parser, using
     * configuration of this reader, except that expected value type
     * is specified with the call (instead of currently configured root type).
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @SuppressWarnings("unchecked")
    @Override
    public <T> T readValue(JsonParser p, Class<T> valueType) throws IOException
    {
        return (T) forType(valueType).readValue(p);
    }

    
Convenience method that binds content read using given parser, using configuration of this reader, except that expected value type is specified with the call (instead of currently configured root type). Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that binds content read using given parser, using
     * configuration of this reader, except that expected value type
     * is specified with the call (instead of currently configured root type).
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @SuppressWarnings("unchecked")
    @Override
    public <T> T readValue(JsonParser p, TypeReference<?> valueTypeRef) throws IOException
    {
        return (T) forType(valueTypeRef).readValue(p);
    }

    
Convenience method that binds content read using given parser, using configuration of this reader, except that expected value type is specified with the call (instead of currently configured root type). Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that binds content read using given parser, using
     * configuration of this reader, except that expected value type
     * is specified with the call (instead of currently configured root type).
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @Override
    @SuppressWarnings("unchecked")
    public <T> T readValue(JsonParser p, ResolvedType valueType) throws IOException {
        return (T) forType((JavaType)valueType).readValue(p);
    }

    
Type-safe overloaded method, basically alias for readValue(JsonParser, ResolvedType). 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Type-safe overloaded method, basically alias for {@link #readValue(JsonParser, ResolvedType)}.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(JsonParser p, JavaType valueType) throws IOException {
        return (T) forType(valueType).readValue(p);
    }

    
Convenience method that is equivalent to:
  withType(valueType).readValues(p);

 Method reads a sequence of Objects from parser stream. Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser MUST point to the first token of
the first element, OR not point to any token (in which case it is advanced
to the next token). This means, specifically, that for wrapped sequences,
parser MUST NOT point to the surrounding START_ARRAY (one that
contains values to read) but rather to the token following it which is the first
token of the first value to read.

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that is equivalent to:
     *<pre>
     *   withType(valueType).readValues(p);
     *</pre>
     *<p>
     * Method reads a sequence of Objects from parser stream.
     * Sequence can be either root-level "unwrapped" sequence (without surrounding
     * JSON array), or a sequence contained in a JSON Array.
     * In either case {@link JsonParser} <b>MUST</b> point to the first token of
     * the first element, OR not point to any token (in which case it is advanced
     * to the next token). This means, specifically, that for wrapped sequences,
     * parser MUST NOT point to the surrounding <code>START_ARRAY</code> (one that
     * contains values to read) but rather to the token following it which is the first
     * token of the first value to read.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @Override
    public <T> Iterator<T> readValues(JsonParser p, Class<T> valueType) throws IOException {
        return forType(valueType).readValues(p);
    }

    
Convenience method that is equivalent to:
  withType(valueTypeRef).readValues(p);

 Method reads a sequence of Objects from parser stream. Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser MUST point to the first token of
the first element, OR not point to any token (in which case it is advanced
to the next token). This means, specifically, that for wrapped sequences,
parser MUST NOT point to the surrounding START_ARRAY (one that
contains values to read) but rather to the token following it which is the first
token of the first value to read.

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that is equivalent to:
     *<pre>
     *   withType(valueTypeRef).readValues(p);
     *</pre>
     *<p>
     * Method reads a sequence of Objects from parser stream.
     * Sequence can be either root-level "unwrapped" sequence (without surrounding
     * JSON array), or a sequence contained in a JSON Array.
     * In either case {@link JsonParser} <b>MUST</b> point to the first token of
     * the first element, OR not point to any token (in which case it is advanced
     * to the next token). This means, specifically, that for wrapped sequences,
     * parser MUST NOT point to the surrounding <code>START_ARRAY</code> (one that
     * contains values to read) but rather to the token following it which is the first
     * token of the first value to read.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @Override
    public <T> Iterator<T> readValues(JsonParser p, TypeReference<?> valueTypeRef) throws IOException {
        return forType(valueTypeRef).readValues(p);
    }
    
    
Convenience method that is equivalent to:
  withType(valueType).readValues(p);

 Method reads a sequence of Objects from parser stream. Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser MUST point to the first token of
the first element, OR not point to any token (in which case it is advanced
to the next token). This means, specifically, that for wrapped sequences,
parser MUST NOT point to the surrounding START_ARRAY (one that
contains values to read) but rather to the token following it which is the first
token of the first value to read.

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that is equivalent to:
     *<pre>
     *   withType(valueType).readValues(p);
     *</pre>
     *<p>
     * Method reads a sequence of Objects from parser stream.
     * Sequence can be either root-level "unwrapped" sequence (without surrounding
     * JSON array), or a sequence contained in a JSON Array.
     * In either case {@link JsonParser} <b>MUST</b> point to the first token of
     * the first element, OR not point to any token (in which case it is advanced
     * to the next token). This means, specifically, that for wrapped sequences,
     * parser MUST NOT point to the surrounding <code>START_ARRAY</code> (one that
     * contains values to read) but rather to the token following it which is the first
     * token of the first value to read.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @Override
    public <T> Iterator<T> readValues(JsonParser p, ResolvedType valueType) throws IOException {
        return readValues(p, (JavaType) valueType);
    }

    
Convenience method that is equivalent to:
  withType(valueType).readValues(p);

 Method reads a sequence of Objects from parser stream. Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser MUST point to the first token of
the first element, OR not point to any token (in which case it is advanced
to the next token). This means, specifically, that for wrapped sequences,
parser MUST NOT point to the surrounding START_ARRAY (one that
contains values to read) but rather to the token following it which is the first
token of the first value to read.

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that is equivalent to:
     *<pre>
     *   withType(valueType).readValues(p);
     *</pre>
     *<p>
     * Method reads a sequence of Objects from parser stream.
     * Sequence can be either root-level "unwrapped" sequence (without surrounding
     * JSON array), or a sequence contained in a JSON Array.
     * In either case {@link JsonParser} <b>MUST</b> point to the first token of
     * the first element, OR not point to any token (in which case it is advanced
     * to the next token). This means, specifically, that for wrapped sequences,
     * parser MUST NOT point to the surrounding <code>START_ARRAY</code> (one that
     * contains values to read) but rather to the token following it which is the first
     * token of the first value to read.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    public <T> Iterator<T> readValues(JsonParser p, JavaType valueType) throws IOException {
        return forType(valueType).readValues(p);
    }

    /*
    /**********************************************************
    /* TreeCodec impl
    /**********************************************************
     */

    @Override
    public JsonNode createArrayNode() {
        return _config.getNodeFactory().arrayNode();
    }

    @Override
    public JsonNode createObjectNode() {
        return _config.getNodeFactory().objectNode();
    }

    @Override
    public JsonParser treeAsTokens(TreeNode n) {
        // 05-Dec-2017, tatu: Important! Must clear "valueToUpdate" since we do not
        //    want update to be applied here, as a side effect
        ObjectReader codec = withValueToUpdate(null);
        return new TreeTraversingParser((JsonNode) n, codec);
    }

    
Convenience method that binds content read using given parser, using
configuration of this reader, except that content is bound as
JSON tree instead of configured root value type.
 Note: if an object was specified with withValueToUpdate, it will be ignored. 

NOTE: this method never tries to auto-detect format, since actual
(data-format specific) parser is given.
/**
     * Convenience method that binds content read using given parser, using
     * configuration of this reader, except that content is bound as
     * JSON tree instead of configured root value type.
     *<p>
     * Note: if an object was specified with {@link #withValueToUpdate}, it
     * will be ignored.
     *<p>
     * NOTE: this method never tries to auto-detect format, since actual
     * (data-format specific) parser is given.
     */
    @SuppressWarnings("unchecked")
    @Override
    public <T extends TreeNode> T readTree(JsonParser p) throws IOException {
        return (T) _bindAsTree(p);
    }
     
    @Override
    public void writeTree(JsonGenerator g, TreeNode rootNode) {
        throw new UnsupportedOperationException();
    }
    
    /*
    /**********************************************************
    /* Deserialization methods; others similar to what ObjectMapper has
    /**********************************************************
     */
    
    
Method that binds content read from given input source, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given input source,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(InputStream src) throws IOException
    {
        if (_dataFormatReaders != null) {
            return (T) _detectBindAndClose(_dataFormatReaders.findFormat(src), false);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that binds content read from given input source, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given input source,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(Reader src) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that binds content read from given JSON string, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given JSON string,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(String src) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that binds content read from given byte array, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given byte array,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(byte[] src) throws IOException
    {
        if (_dataFormatReaders != null) {
            return (T) _detectBindAndClose(src, 0, src.length);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that binds content read from given byte array, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given byte array,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(byte[] src, int offset, int length)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return (T) _detectBindAndClose(src, offset, length);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src, offset, length),
                false));
    }
    
    @SuppressWarnings("unchecked")
    public <T> T readValue(File src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return (T) _detectBindAndClose(_dataFormatReaders.findFormat(_inputStream(src)), true);
        }

        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that binds content read from given input source, using configuration of this reader. Value return is either newly constructed, or root value that was specified with withValueToUpdate(Object). /**
     * Method that binds content read from given input source,
     * using configuration of this reader.
     * Value return is either newly constructed, or root value that
     * was specified with {@link #withValueToUpdate(Object)}.
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(URL src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return (T) _detectBindAndClose(_dataFormatReaders.findFormat(_inputStream(src)), true);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Convenience method for converting results from given JSON tree into given
value type. Basically short-cut for:
  objectReader.readValue(src.traverse())

/**
     * Convenience method for converting results from given JSON tree into given
     * value type. Basically short-cut for:
     *<pre>
     *   objectReader.readValue(src.traverse())
     *</pre>
     */
    @SuppressWarnings({ "unchecked", "resource" })
    public <T> T readValue(JsonNode src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        return (T) _bindAndClose(_considerFilter(treeAsTokens(src), false));
    }

    
Since:
2.8/**
     * @since 2.8
     */
    @SuppressWarnings("unchecked")
    public <T> T readValue(DataInput src) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        return (T) _bindAndClose(_considerFilter(_parserFactory.createParser(src), false));
    }

    
Method that reads content from given input source,
using configuration of this reader, and binds it as JSON Tree.
 Note that if an object was specified with a call to withValueToUpdate(Object) it will just be ignored; result is always a newly constructed JsonNode instance. /**
     * Method that reads content from given input source,
     * using configuration of this reader, and binds it as JSON Tree.
     *<p>
     * Note that if an object was specified with a call to
     * {@link #withValueToUpdate(Object)}
     * it will just be ignored; result is always a newly constructed
     * {@link JsonNode} instance.
     */
    public JsonNode readTree(InputStream in) throws IOException
    {
        if (_dataFormatReaders != null) {
            return _detectBindAndCloseAsTree(in);
        }
        return _bindAndCloseAsTree(_considerFilter(_parserFactory.createParser(in), false));
    }
    
    
Method that reads content from given input source,
using configuration of this reader, and binds it as JSON Tree.
 Note that if an object was specified with a call to withValueToUpdate(Object) it will just be ignored; result is always a newly constructed JsonNode instance. /**
     * Method that reads content from given input source,
     * using configuration of this reader, and binds it as JSON Tree.
     *<p>
     * Note that if an object was specified with a call to
     * {@link #withValueToUpdate(Object)}
     * it will just be ignored; result is always a newly constructed
     * {@link JsonNode} instance.
     */
    public JsonNode readTree(Reader r) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(r);
        }
        return _bindAndCloseAsTree(_considerFilter(_parserFactory.createParser(r), false));
    }

    
Method that reads content from given JSON input String,
using configuration of this reader, and binds it as JSON Tree.
 Note that if an object was specified with a call to withValueToUpdate(Object) it will just be ignored; result is always a newly constructed JsonNode instance. /**
     * Method that reads content from given JSON input String,
     * using configuration of this reader, and binds it as JSON Tree.
     *<p>
     * Note that if an object was specified with a call to
     * {@link #withValueToUpdate(Object)}
     * it will just be ignored; result is always a newly constructed
     * {@link JsonNode} instance.
     */
    public JsonNode readTree(String json) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(json);
        }
        return _bindAndCloseAsTree(_considerFilter(_parserFactory.createParser(json), false));
    }

    public JsonNode readTree(DataInput src) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        return _bindAndCloseAsTree(_considerFilter(_parserFactory.createParser(src), false));
    }

    /*
    /**********************************************************
    /* Deserialization methods; reading sequence of values
    /**********************************************************
     */
    
    
Method for reading sequence of Objects from parser stream.
 Sequence can be either root-level "unwrapped" sequence (without surrounding JSON array), or a sequence contained in a JSON Array. In either case JsonParser must point to the first token of the first element, OR not point to any token (in which case it is advanced to the next token). This means, specifically, that for wrapped sequences, parser MUST NOT point to the surrounding START_ARRAY but rather
to the token following it.
/**
     * Method for reading sequence of Objects from parser stream.
     *<p>
     * Sequence can be either root-level "unwrapped" sequence (without surrounding
     * JSON array), or a sequence contained in a JSON Array.
     * In either case {@link JsonParser} must point to the first token of
     * the first element, OR not point to any token (in which case it is advanced
     * to the next token). This means, specifically, that for wrapped sequences,
     * parser MUST NOT point to the surrounding <code>START_ARRAY</code> but rather
     * to the token following it.
     */
    public <T> MappingIterator<T> readValues(JsonParser p)
        throws IOException
    {
        DeserializationContext ctxt = createDeserializationContext(p);
        // false -> do not close as caller gave parser instance
        return _newIterator(p, ctxt, _findRootDeserializer(ctxt), false);
    }
    
    
Method for reading sequence of Objects from parser stream.

Sequence can be either wrapped or unwrapped root-level sequence:
wrapped means that the elements are enclosed in JSON Array;
and unwrapped that elements are directly accessed at main level.
Assumption is that iff the first token of the document is
START_ARRAY, we have a wrapped sequence; otherwise
unwrapped. For wrapped sequences, leading START_ARRAY is skipped, so that for both cases, underlying JsonParser will point to what is expected to be the first token of the first element. 
 Note that the wrapped vs unwrapped logic means that it is NOT possible to use this method for reading an unwrapped sequence of elements written as JSON Arrays: to read such sequences, one has to use readValues(JsonParser), making sure parser points to the first token of the first element (i.e. the second START_ARRAY which is part of the first element).
/**
     * Method for reading sequence of Objects from parser stream.
     *<p>
     * Sequence can be either wrapped or unwrapped root-level sequence:
     * wrapped means that the elements are enclosed in JSON Array;
     * and unwrapped that elements are directly accessed at main level.
     * Assumption is that iff the first token of the document is
     * <code>START_ARRAY</code>, we have a wrapped sequence; otherwise
     * unwrapped. For wrapped sequences, leading <code>START_ARRAY</code>
     * is skipped, so that for both cases, underlying {@link JsonParser}
     * will point to what is expected to be the first token of the first
     * element.
     *<p>
     * Note that the wrapped vs unwrapped logic means that it is NOT
     * possible to use this method for reading an unwrapped sequence
     * of elements written as JSON Arrays: to read such sequences, one
     * has to use {@link #readValues(JsonParser)}, making sure parser
     * points to the first token of the first element (i.e. the second
     * <code>START_ARRAY</code> which is part of the first element).
     */
    public <T> MappingIterator<T> readValues(InputStream src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return _detectBindAndReadValues(_dataFormatReaders.findFormat(src), false);
        }
        
        return _bindAndReadValues(_considerFilter(_parserFactory.createParser(src), true));
    }
    
    
Overloaded version of readValue(InputStream). /**
     * Overloaded version of {@link #readValue(InputStream)}.
     */
    @SuppressWarnings("resource")
    public <T> MappingIterator<T> readValues(Reader src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        JsonParser p = _considerFilter(_parserFactory.createParser(src), true);
        DeserializationContext ctxt = createDeserializationContext(p);
        _initForMultiRead(ctxt, p);
        p.nextToken();
        return _newIterator(p, ctxt, _findRootDeserializer(ctxt), true);
    }
    
    
Overloaded version of readValue(InputStream). 
Params:
json – String that contains JSON content to parse/**
     * Overloaded version of {@link #readValue(InputStream)}.
     * 
     * @param json String that contains JSON content to parse
     */
    @SuppressWarnings("resource")
    public <T> MappingIterator<T> readValues(String json)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(json);
        }
        JsonParser p = _considerFilter(_parserFactory.createParser(json), true);
        DeserializationContext ctxt = createDeserializationContext(p);
        _initForMultiRead(ctxt, p);
        p.nextToken();
        return _newIterator(p, ctxt, _findRootDeserializer(ctxt), true);
    }

    
Overloaded version of readValue(InputStream). /**
     * Overloaded version of {@link #readValue(InputStream)}.
     */
    public <T> MappingIterator<T> readValues(byte[] src, int offset, int length)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return _detectBindAndReadValues(_dataFormatReaders.findFormat(src, offset, length), false);
        }
        return _bindAndReadValues(_considerFilter(_parserFactory.createParser(src, offset, length),
                true));
    }

    
Overloaded version of readValue(InputStream). /**
     * Overloaded version of {@link #readValue(InputStream)}.
     */
    public final <T> MappingIterator<T> readValues(byte[] src)
            throws IOException {
        return readValues(src, 0, src.length);
    }
    
    
Overloaded version of readValue(InputStream). /**
     * Overloaded version of {@link #readValue(InputStream)}.
     */
    public <T> MappingIterator<T> readValues(File src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return _detectBindAndReadValues(
                    _dataFormatReaders.findFormat(_inputStream(src)), false);
        }
        return _bindAndReadValues(_considerFilter(_parserFactory.createParser(src), true));
    }

    
Overloaded version of readValue(InputStream). 
Params:
src – URL to read to access JSON content to parse./**
     * Overloaded version of {@link #readValue(InputStream)}.
     * 
     * @param src URL to read to access JSON content to parse.
     */
    public <T> MappingIterator<T> readValues(URL src)
        throws IOException
    {
        if (_dataFormatReaders != null) {
            return _detectBindAndReadValues(
                    _dataFormatReaders.findFormat(_inputStream(src)), true);
        }
        return _bindAndReadValues(_considerFilter(_parserFactory.createParser(src), true));
    }

    
Since:
2.8/**
     * @since 2.8
     */
    public <T> MappingIterator<T> readValues(DataInput src) throws IOException
    {
        if (_dataFormatReaders != null) {
            _reportUndetectableSource(src);
        }
        return _bindAndReadValues(_considerFilter(_parserFactory.createParser(src), true));
    }

    /*
    /**********************************************************
    /* Implementation of rest of ObjectCodec methods
    /**********************************************************
     */

    @Override
    public <T> T treeToValue(TreeNode n, Class<T> valueType) throws JsonProcessingException
    {
        try {
            return readValue(treeAsTokens(n), valueType);
        } catch (JsonProcessingException e) {
            throw e;
        } catch (IOException e) { // should not occur, no real i/o...
            throw JsonMappingException.fromUnexpectedIOE(e);
        }
    }    

    @Override
    public void writeValue(JsonGenerator gen, Object value) throws IOException {
        throw new UnsupportedOperationException("Not implemented for ObjectReader");
    }

    /*
    /**********************************************************
    /* Helper methods, data-binding
    /**********************************************************
     */

    
Actual implementation of value reading+binding operation.
/**
     * Actual implementation of value reading+binding operation.
     */
    protected Object _bind(JsonParser p, Object valueToUpdate) throws IOException
    {
        /* First: may need to read the next token, to initialize state (either
         * before first read from parser, or after previous token has been cleared)
         */
        Object result;
        final DeserializationContext ctxt = createDeserializationContext(p);
        JsonToken t = _initForReading(ctxt, p);
        if (t == JsonToken.VALUE_NULL) {
            if (valueToUpdate == null) {
                result = _findRootDeserializer(ctxt).getNullValue(ctxt);
            } else {
                result = valueToUpdate;
            }
        } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
            result = valueToUpdate;
        } else { // pointing to event other than null
            JsonDeserializer<Object> deser = _findRootDeserializer(ctxt);
            if (_unwrapRoot) {
                result = _unwrapAndDeserialize(p, ctxt, _valueType, deser);
            } else {
                if (valueToUpdate == null) {
                    result = deser.deserialize(p, ctxt);
                } else {
                    // 20-Mar-2017, tatu: Important! May be different from `valueToUpdate`
                    //   for immutable Objects like Java arrays; logical result
                    result = deser.deserialize(p, ctxt, valueToUpdate);
                }
            }
        }
        // Need to consume the token too
        p.clearCurrentToken();
        if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
            _verifyNoTrailingTokens(p, ctxt, _valueType);
        }
        return result;
    }

    protected Object _bindAndClose(JsonParser p0) throws IOException
    {
        try (JsonParser p = p0) {
            Object result;

            DeserializationContext ctxt = createDeserializationContext(p);
            JsonToken t = _initForReading(ctxt, p);
            if (t == JsonToken.VALUE_NULL) {
                if (_valueToUpdate == null) {
                    result = _findRootDeserializer(ctxt).getNullValue(ctxt);
                } else {
                    result = _valueToUpdate;
                }
            } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
                result = _valueToUpdate;
            } else {
                JsonDeserializer<Object> deser = _findRootDeserializer(ctxt);
                if (_unwrapRoot) {
                    result = _unwrapAndDeserialize(p, ctxt, _valueType, deser);
                } else {
                    if (_valueToUpdate == null) {
                        result = deser.deserialize(p, ctxt);
                    } else {
                        deser.deserialize(p, ctxt, _valueToUpdate);
                        result = _valueToUpdate;                    
                    }
                }
            }
            if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
                _verifyNoTrailingTokens(p, ctxt, _valueType);
            }
            return result;
        }
    }

    protected final JsonNode _bindAndCloseAsTree(JsonParser p0) throws IOException {
        try (JsonParser p = p0) {
            return _bindAsTree(p);
        }
    }

    protected final JsonNode _bindAsTree(JsonParser p) throws IOException
    {
        // 27-Oct-2016, tatu: Need to inline `_initForReading()` due to
        //   special requirements by tree reading (no fail on eof)
        
        _config.initialize(p);
        if (_schema != null) {
            p.setSchema(_schema);
        }

        JsonToken t = p.getCurrentToken();
        if (t == null) {
            t = p.nextToken();
            if (t == null) { // [databind#1406]: expose end-of-input as `null`
                return null;
            }
        }
        DeserializationContext ctxt = createDeserializationContext(p);
        if (t == JsonToken.VALUE_NULL) {
            return ctxt.getNodeFactory().nullNode();
        }
        JsonDeserializer<Object> deser = _findTreeDeserializer(ctxt);
        Object result;
        if (_unwrapRoot) {
            result = _unwrapAndDeserialize(p, ctxt, JSON_NODE_TYPE, deser);
        } else {
            result = deser.deserialize(p, ctxt);
            if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
                _verifyNoTrailingTokens(p, ctxt, JSON_NODE_TYPE);
            }
        }
        return (JsonNode) result;
    }

    
Since:
2.1/**
     * @since 2.1
     */
    protected <T> MappingIterator<T> _bindAndReadValues(JsonParser p) throws IOException
    {
        DeserializationContext ctxt = createDeserializationContext(p);
        _initForMultiRead(ctxt, p);
        p.nextToken();
        return _newIterator(p, ctxt, _findRootDeserializer(ctxt), true);
    }

    protected Object _unwrapAndDeserialize(JsonParser p, DeserializationContext ctxt,
            JavaType rootType, JsonDeserializer<Object> deser) throws IOException
    {
        PropertyName expRootName = _config.findRootName(rootType);
        // 12-Jun-2015, tatu: Should try to support namespaces etc but...
        String expSimpleName = expRootName.getSimpleName();

        if (p.getCurrentToken() != JsonToken.START_OBJECT) {
            ctxt.reportWrongTokenException(rootType, JsonToken.START_OBJECT,
                    "Current token not START_OBJECT (needed to unwrap root name '%s'), but %s",
                    expSimpleName, p.getCurrentToken());
        }
        if (p.nextToken() != JsonToken.FIELD_NAME) {
            ctxt.reportWrongTokenException(rootType, JsonToken.FIELD_NAME,
                    "Current token not FIELD_NAME (to contain expected root name '%s'), but %s", 
                    expSimpleName, p.getCurrentToken());
        }
        String actualName = p.getCurrentName();
        if (!expSimpleName.equals(actualName)) {
            ctxt.reportInputMismatch(rootType,
                    "Root name '%s' does not match expected ('%s') for type %s",
                    actualName, expSimpleName, rootType);
        }
        // ok, then move to value itself....
        p.nextToken();
        Object result;
        if (_valueToUpdate == null) {
            result = deser.deserialize(p, ctxt);
        } else {
            deser.deserialize(p, ctxt, _valueToUpdate);
            result = _valueToUpdate;                    
        }
        // and last, verify that we now get matching END_OBJECT
        if (p.nextToken() != JsonToken.END_OBJECT) {
            ctxt.reportWrongTokenException(rootType, JsonToken.END_OBJECT,
                    "Current token not END_OBJECT (to match wrapper object with root name '%s'), but %s",
                    expSimpleName, p.getCurrentToken());
        }
        if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
            _verifyNoTrailingTokens(p, ctxt, _valueType);
        }
        return result;
    }

    
Consider filter when creating JsonParser.  
/**
     * Consider filter when creating JsonParser.  
     */
    protected JsonParser _considerFilter(final JsonParser p, boolean multiValue) {
        // 26-Mar-2016, tatu: Need to allow multiple-matches at least if we have
        //    have a multiple-value read (that is, "readValues()").
        return ((_filter == null) || FilteringParserDelegate.class.isInstance(p))
                ? p : new FilteringParserDelegate(p, _filter, false, multiValue);
    }

    
Since:
2.9/**
     * @since 2.9
     */
    protected final void _verifyNoTrailingTokens(JsonParser p, DeserializationContext ctxt,
            JavaType bindType)
        throws IOException
    {
        JsonToken t = p.nextToken();
        if (t != null) {
            Class<?> bt = ClassUtil.rawClass(bindType);
            if (bt == null) {
                if (_valueToUpdate != null) {
                    bt = _valueToUpdate.getClass();
                }
            }
            ctxt.reportTrailingTokens(bt, p, t);
        }
    }

    /*
    /**********************************************************
    /* Internal methods, format auto-detection
    /**********************************************************
     */
    
    @SuppressWarnings("resource")
    protected Object _detectBindAndClose(byte[] src, int offset, int length) throws IOException
    {
        DataFormatReaders.Match match = _dataFormatReaders.findFormat(src, offset, length);
        if (!match.hasMatch()) {
            _reportUnkownFormat(_dataFormatReaders, match);
        }
        JsonParser p = match.createParserWithMatch();
        return match.getReader()._bindAndClose(p);
    }

    @SuppressWarnings("resource")
    protected Object _detectBindAndClose(DataFormatReaders.Match match, boolean forceClosing)
        throws IOException
    {
        if (!match.hasMatch()) {
            _reportUnkownFormat(_dataFormatReaders, match);
        }
        JsonParser p = match.createParserWithMatch();
        // One more thing: we Own the input stream now; and while it's 
        // not super clean way to do it, we must ensure closure so:
        if (forceClosing) {
            p.enable(JsonParser.Feature.AUTO_CLOSE_SOURCE);
        }
        // important: use matching ObjectReader (may not be 'this')
        return match.getReader()._bindAndClose(p);
    }

    @SuppressWarnings("resource")
    protected <T> MappingIterator<T> _detectBindAndReadValues(DataFormatReaders.Match match, boolean forceClosing)
        throws IOException
    {
        if (!match.hasMatch()) {
            _reportUnkownFormat(_dataFormatReaders, match);
        }
        JsonParser p = match.createParserWithMatch();
        // One more thing: we Own the input stream now; and while it's 
        // not super clean way to do it, we must ensure closure so:
        if (forceClosing) {
            p.enable(JsonParser.Feature.AUTO_CLOSE_SOURCE);
        }
        // important: use matching ObjectReader (may not be 'this')
        return match.getReader()._bindAndReadValues(p);
    }
    
    @SuppressWarnings("resource")
    protected JsonNode _detectBindAndCloseAsTree(InputStream in) throws IOException
    {
        DataFormatReaders.Match match = _dataFormatReaders.findFormat(in);
        if (!match.hasMatch()) {
            _reportUnkownFormat(_dataFormatReaders, match);
        }
        JsonParser p = match.createParserWithMatch();
        p.enable(JsonParser.Feature.AUTO_CLOSE_SOURCE);
        return match.getReader()._bindAndCloseAsTree(p);
    }
    
    
Method called to indicate that format detection failed to detect format
of given input
/**
     * Method called to indicate that format detection failed to detect format
     * of given input
     */
    protected void _reportUnkownFormat(DataFormatReaders detector, DataFormatReaders.Match match)
        throws JsonProcessingException
    {
        // 17-Aug-2015, tatu: Unfortunately, no parser/generator available so:
        throw new JsonParseException(null, "Cannot detect format from input, does not look like any of detectable formats "
                +detector.toString());
    }

    /*
    /**********************************************************
    /* Internal methods, other
    /**********************************************************
     */

    
Since:
2.2/**
     * @since 2.2
     */
    protected void _verifySchemaType(FormatSchema schema)
    {
        if (schema != null) {
            if (!_parserFactory.canUseSchema(schema)) {
                    throw new IllegalArgumentException("Cannot use FormatSchema of type "+schema.getClass().getName()
                            +" for format "+_parserFactory.getFormatName());
            }
        }
    }

    
Internal helper method called to create an instance of DeserializationContext for deserializing a single root value. Can be overridden if a custom context is needed. /**
     * Internal helper method called to create an instance of {@link DeserializationContext}
     * for deserializing a single root value.
     * Can be overridden if a custom context is needed.
     */
    protected DefaultDeserializationContext createDeserializationContext(JsonParser p) {
        return _context.createInstance(_config, p, _injectableValues);
    }

    protected InputStream _inputStream(URL src) throws IOException {
        return src.openStream();
    }

    protected InputStream _inputStream(File f) throws IOException {
        return new FileInputStream(f);
    }

    protected void _reportUndetectableSource(Object src) throws JsonProcessingException
    {
        // 17-Aug-2015, tatu: Unfortunately, no parser/generator available so:
        throw new JsonParseException(null, "Cannot use source of type "
                +src.getClass().getName()+" with format auto-detection: must be byte- not char-based");
    }

    /*
    /**********************************************************
    /* Helper methods, locating deserializers etc
    /**********************************************************
     */
    
    
Method called to locate deserializer for the passed root-level value.
/**
     * Method called to locate deserializer for the passed root-level value.
     */
    protected JsonDeserializer<Object> _findRootDeserializer(DeserializationContext ctxt)
        throws JsonMappingException
    {
        if (_rootDeserializer != null) {
            return _rootDeserializer;
        }

        // Sanity check: must have actual type...
        JavaType t = _valueType;
        if (t == null) {
            ctxt.reportBadDefinition((JavaType) null,
                    "No value type configured for ObjectReader");
        }
        // First: have we already seen it?
        JsonDeserializer<Object> deser = _rootDeserializers.get(t);
        if (deser != null) {
            return deser;
        }
        // Nope: need to ask provider to resolve it
        deser = ctxt.findRootValueDeserializer(t);
        if (deser == null) { // can this happen?
            ctxt.reportBadDefinition(t, "Cannot find a deserializer for type "+t);
        }
        _rootDeserializers.put(t, deser);
        return deser;
    }

    
Since:
2.6/**
     * @since 2.6
     */
    protected JsonDeserializer<Object> _findTreeDeserializer(DeserializationContext ctxt)
        throws JsonMappingException
    {
        JsonDeserializer<Object> deser = _rootDeserializers.get(JSON_NODE_TYPE);
        if (deser == null) {
            // Nope: need to ask provider to resolve it
            deser = ctxt.findRootValueDeserializer(JSON_NODE_TYPE);
            if (deser == null) { // can this happen?
                ctxt.reportBadDefinition(JSON_NODE_TYPE,
                        "Cannot find a deserializer for type "+JSON_NODE_TYPE);
            }
            _rootDeserializers.put(JSON_NODE_TYPE, deser);
        }
        return deser;
    }

    
Method called to locate deserializer ahead of time, if permitted
by configuration. Method also is NOT to throw an exception if
access fails.
/**
     * Method called to locate deserializer ahead of time, if permitted
     * by configuration. Method also is NOT to throw an exception if
     * access fails.
     */
    protected JsonDeserializer<Object> _prefetchRootDeserializer(JavaType valueType)
    {
        if ((valueType == null) || !_config.isEnabled(DeserializationFeature.EAGER_DESERIALIZER_FETCH)) {
            return null;
        }
        // already cached?
        JsonDeserializer<Object> deser = _rootDeserializers.get(valueType);
        if (deser == null) {
            try {
                // If not, need to resolve; for which we need a temporary context as well:
                DeserializationContext ctxt = createDeserializationContext(null);
                deser = ctxt.findRootValueDeserializer(valueType);
                if (deser != null) {
                    _rootDeserializers.put(valueType, deser);
                }
                return deser;
            } catch (JsonProcessingException e) {
                // need to swallow?
            }
        }
        return deser;
    }
}