/*
 * 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 com.google.gson.Gson;
import com.google.gson.JsonSyntaxException;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;

Adapter for java.sql.Date. Although this class appears stateless, it is not.
DateFormat captures its time zone and locale when it is created, which gives
this class state. DateFormat isn't thread safe either, so this class has
to synchronize its read and write methods.
/**
 * Adapter for java.sql.Date. Although this class appears stateless, it is not.
 * DateFormat captures its time zone and locale when it is created, which gives
 * this class state. DateFormat isn't thread safe either, so this class has
 * to synchronize its read and write methods.
 */
public final class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {
  public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() {
    @SuppressWarnings("unchecked") // we use a runtime check to make sure the 'T's equal
    @Override public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
      return typeToken.getRawType() == java.sql.Date.class
          ? (TypeAdapter<T>) new SqlDateTypeAdapter() : null;
    }
  };

  private final DateFormat format = new SimpleDateFormat("MMM d, yyyy");

  @Override
  public synchronized java.sql.Date read(JsonReader in) throws IOException {
    if (in.peek() == JsonToken.NULL) {
      in.nextNull();
      return null;
    }
    try {
      final long utilDate = format.parse(in.nextString()).getTime();
      return new java.sql.Date(utilDate);
    } catch (ParseException e) {
      throw new JsonSyntaxException(e);
    }
  }

  @Override
  public synchronized void write(JsonWriter out, java.sql.Date value) throws IOException {
    out.value(value == null ? null : format.format(value));
  }
}