package com.fasterxml.jackson.databind.ser.std;

import java.io.IOException;
import java.lang.reflect.Type;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.type.WritableTypeId;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;

Simple general purpose serializer, useful for any type for which Object.toString returns the desired JSON value.
/** * Simple general purpose serializer, useful for any * type for which {@link Object#toString} returns the desired JSON * value. */
@JacksonStdImpl @SuppressWarnings("serial") public class ToStringSerializer extends StdSerializer<Object> {
Singleton instance to use.
/** * Singleton instance to use. */
public final static ToStringSerializer instance = new ToStringSerializer();

Note: usually you should NOT create new instances, but instead use instance which is stateless and fully thread-safe. However, there are cases where constructor is needed; for example, when using explicit serializer annotations like JsonSerialize.using.

/** *<p> * Note: usually you should NOT create new instances, but instead use * {@link #instance} which is stateless and fully thread-safe. However, * there are cases where constructor is needed; for example, * when using explicit serializer annotations like * {@link com.fasterxml.jackson.databind.annotation.JsonSerialize#using}. */
public ToStringSerializer() { super(Object.class); }
Sometimes it may actually make sense to retain actual handled type, so...
Since:2.5
/** * Sometimes it may actually make sense to retain actual handled type, so... * * @since 2.5 */
public ToStringSerializer(Class<?> handledType) { super(handledType, false); } @Override public boolean isEmpty(SerializerProvider prov, Object value) { return value.toString().isEmpty(); } @Override public void serialize(Object value, JsonGenerator gen, SerializerProvider provider) throws IOException { gen.writeString(value.toString()); } /* 01-Mar-2011, tatu: We were serializing as "raw" String; but generally that * is not what we want, since lack of type information would imply real * String type. */
Default implementation will write type prefix, call regular serialization method (since assumption is that value itself does not need JSON Array or Object start/end markers), and then write type suffix. This should work for most cases; some sub-classes may want to change this behavior.
/** * Default implementation will write type prefix, call regular serialization * method (since assumption is that value itself does not need JSON * Array or Object start/end markers), and then write type suffix. * This should work for most cases; some sub-classes may want to * change this behavior. */
@Override public void serializeWithType(Object value, JsonGenerator g, SerializerProvider provider, TypeSerializer typeSer) throws IOException { WritableTypeId typeIdDef = typeSer.writeTypePrefix(g, typeSer.typeId(value, JsonToken.VALUE_STRING)); serialize(value, g, provider); typeSer.writeTypeSuffix(g, typeIdDef); } @Override public JsonNode getSchema(SerializerProvider provider, Type typeHint) throws JsonMappingException { return createSchemaNode("string", true); } @Override public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) throws JsonMappingException { visitStringFormat(visitor, typeHint); } }