alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (ArrayTypeAdapter.java)

This example Java source code file (ArrayTypeAdapter.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

arraylist, arraytypeadapter, class, genericarraytype, gson, ioexception, object, override, reflection, suppresswarnings, typeadapter, typeadapterfactory, typeadapterruntimetypewrapper, typetoken, util

The ArrayTypeAdapter.java Java example source code

/*
 * Copyright (C) 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.gson.internal.bind;

import java.io.IOException;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.internal.$Gson$Types;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;

/**
 * Adapt an array of objects.
 */
public final class ArrayTypeAdapter<E> extends TypeAdapter {
  public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() {
    @SuppressWarnings({"unchecked", "rawtypes"})
    @Override public <T> TypeAdapter create(Gson gson, TypeToken typeToken) {
      Type type = typeToken.getType();
      if (!(type instanceof GenericArrayType || type instanceof Class && ((Class<?>) type).isArray())) {
        return null;
      }

      Type componentType = $Gson$Types.getArrayComponentType(type);
      TypeAdapter<?> componentTypeAdapter = gson.getAdapter(TypeToken.get(componentType));
      return new ArrayTypeAdapter(
              gson, componentTypeAdapter, $Gson$Types.getRawType(componentType));
    }
  };

  private final Class<E> componentType;
  private final TypeAdapter<E> componentTypeAdapter;

  public ArrayTypeAdapter(Gson context, TypeAdapter<E> componentTypeAdapter, Class componentType) {
    this.componentTypeAdapter =
      new TypeAdapterRuntimeTypeWrapper<E>(context, componentTypeAdapter, componentType);
    this.componentType = componentType;
  }

  @Override public Object read(JsonReader in) throws IOException {
    if (in.peek() == JsonToken.NULL) {
      in.nextNull();
      return null;
    }

    List<E> list = new ArrayList();
    in.beginArray();
    while (in.hasNext()) {
      E instance = componentTypeAdapter.read(in);
      list.add(instance);
    }
    in.endArray();
    Object array = Array.newInstance(componentType, list.size());
    for (int i = 0; i < list.size(); i++) {
      Array.set(array, i, list.get(i));
    }
    return array;
  }

  @SuppressWarnings("unchecked")
  @Override public void write(JsonWriter out, Object array) throws IOException {
    if (array == null) {
      out.nullValue();
      return;
    }

    out.beginArray();
    for (int i = 0, length = Array.getLength(array); i < length; i++) {
      E value = (E) Array.get(array, i);
      componentTypeAdapter.write(out, value);
    }
    out.endArray();
  }
}




Other Java examples (source code examples)


Here is a short list of links related to this Java ArrayTypeAdapter.java source code file:
... this post is sponsored by my books ...

#1 New Release!
FP Best Seller

 

new blog posts

 

Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.