gson/com/google/gson/internal/bind/SqlDateTypeAdapter.java

   1 /*
   2  * Copyright (C) 2011 Google Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package com.google.gson.internal.bind;
  18
  19 import com.google.gson.Gson;
  20 import com.google.gson.JsonSyntaxException;
  21 import com.google.gson.TypeAdapter;
  22 import com.google.gson.TypeAdapterFactory;
  23 import com.google.gson.reflect.TypeToken;
  24 import com.google.gson.stream.JsonReader;
  25 import com.google.gson.stream.JsonToken;
  26 import com.google.gson.stream.JsonWriter;
  27 import java.io.IOException;
  28 import java.text.DateFormat;
  29 import java.text.ParseException;
  30 import java.text.SimpleDateFormat;
  31
  32 /**
  33  * Adapter for java.sql.Date. Although this class appears stateless, it is not.
  34  * DateFormat captures its time zone and locale when it is created, which gives
  35  * this class state. DateFormat isn't thread safe either, so this class has
  36  * to synchronize its read and write methods.
  37  */
  38 public final class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {
  39   public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() {
  40     @SuppressWarnings("unchecked") // we use a runtime check to make sure the 'T's equal
  41     public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
  42       return typeToken.getRawType() == java.sql.Date.class
  43           ? (TypeAdapter<T>) new SqlDateTypeAdapter() : null;
  44     }
  45   };
  46
  47   private final DateFormat format = new SimpleDateFormat("MMM d, yyyy");
  48
  49   @Override
  50   public synchronized java.sql.Date read(JsonReader in) throws IOException {
  51     if (in.peek() == JsonToken.NULL) {
  52       in.nextNull();
  53       return null;
  54     }
  55     try {
  56       final long utilDate = format.parse(in.nextString()).getTime();
  57       return new java.sql.Date(utilDate);
  58     } catch (ParseException e) {
  59       throw new JsonSyntaxException(e);
  60     }
  61   }
  62
  63   @Override
  64   public synchronized void write(JsonWriter out, java.sql.Date value) throws IOException {
  65     out.value(value == null ? null : format.format(value));
  66   }
  67 }