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

import java.io.IOException;
import java.util.*;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.type.WritableTypeId;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonArrayFormatVisitor;
import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatTypes;
import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
import com.fasterxml.jackson.databind.ser.std.StaticListSerializerBase;

Efficient implement for serializing Lists that contains Strings and are random-accessible. The only complexity is due to possibility that serializer for String may be overridde; because of this, logic is needed to ensure that the default serializer is in use to use fastest mode, or if not, to defer to custom String serializer.
/** * Efficient implement for serializing {@link List}s that contains Strings and are random-accessible. * The only complexity is due to possibility that serializer for {@link String} * may be overridde; because of this, logic is needed to ensure that the default * serializer is in use to use fastest mode, or if not, to defer to custom * String serializer. */
@JacksonStdImpl public final class IndexedStringListSerializer extends StaticListSerializerBase<List<String>> { private static final long serialVersionUID = 1L; public final static IndexedStringListSerializer instance = new IndexedStringListSerializer(); /* /********************************************************** /* Life-cycle /********************************************************** */ protected IndexedStringListSerializer() { super(List.class); } public IndexedStringListSerializer(IndexedStringListSerializer src, Boolean unwrapSingle) { super(src, unwrapSingle); } @Override public JsonSerializer<?> _withResolved(BeanProperty prop, Boolean unwrapSingle) { return new IndexedStringListSerializer(this, unwrapSingle); } @Override protected JsonNode contentSchema() { return createSchemaNode("string", true); } @Override protected void acceptContentVisitor(JsonArrayFormatVisitor visitor) throws JsonMappingException { visitor.itemsFormat(JsonFormatTypes.STRING); } /* /********************************************************** /* Actual serialization /********************************************************** */ @Override public void serialize(List<String> value, JsonGenerator g, SerializerProvider provider) throws IOException { final int len = value.size(); if (len == 1) { if (((_unwrapSingle == null) && provider.isEnabled(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED)) || (_unwrapSingle == Boolean.TRUE)) { serializeContents(value, g, provider, 1); return; } } g.writeStartArray(value, len); serializeContents(value, g, provider, len); g.writeEndArray(); } @Override public void serializeWithType(List<String> value, JsonGenerator g, SerializerProvider provider, TypeSerializer typeSer) throws IOException { WritableTypeId typeIdDef = typeSer.writeTypePrefix(g, typeSer.typeId(value, JsonToken.START_ARRAY)); g.setCurrentValue(value); serializeContents(value, g, provider, value.size()); typeSer.writeTypeSuffix(g, typeIdDef); } private final void serializeContents(List<String> value, JsonGenerator g, SerializerProvider provider, int len) throws IOException { int i = 0; try { for (; i < len; ++i) { String str = value.get(i); if (str == null) { provider.defaultSerializeNull(g); } else { g.writeString(str); } } } catch (Exception e) { wrapAndThrow(provider, e, value, i); } } }