gson/com/google/gson/DefaultDateTypeAdapter.java

   1 /*
   2  * Copyright (C) 2008 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;
  18
  19 import java.lang.reflect.Type;
  20 import java.sql.Timestamp;
  21 import java.text.DateFormat;
  22 import java.text.ParseException;
  23 import java.text.SimpleDateFormat;
  24 import java.util.Date;
  25 import java.util.Locale;
  26 import java.util.TimeZone;
  27
  28 /**
  29  * This type adapter supports three subclasses of date: Date, Timestamp, and
  30  * java.sql.Date.
  31  *
  32  * @author Inderjeet Singh
  33  * @author Joel Leitch
  34  */
  35 final class DefaultDateTypeAdapter implements JsonSerializer<Date>, JsonDeserializer<Date> {
  36
  37   // TODO: migrate to streaming adapter
  38
  39   private final DateFormat enUsFormat;
  40   private final DateFormat localFormat;
  41   private final DateFormat iso8601Format;
  42
  43   DefaultDateTypeAdapter() {
  44     this(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.US),
  45         DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT));
  46   }
  47
  48   DefaultDateTypeAdapter(String datePattern) {
  49     this(new SimpleDateFormat(datePattern, Locale.US), new SimpleDateFormat(datePattern));
  50   }
  51
  52   DefaultDateTypeAdapter(int style) {
  53     this(DateFormat.getDateInstance(style, Locale.US), DateFormat.getDateInstance(style));
  54   }
  55
  56   public DefaultDateTypeAdapter(int dateStyle, int timeStyle) {
  57     this(DateFormat.getDateTimeInstance(dateStyle, timeStyle, Locale.US),
  58         DateFormat.getDateTimeInstance(dateStyle, timeStyle));
  59   }
  60
  61   DefaultDateTypeAdapter(DateFormat enUsFormat, DateFormat localFormat) {
  62     this.enUsFormat = enUsFormat;
  63     this.localFormat = localFormat;
  64     this.iso8601Format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US);
  65     this.iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC"));
  66   }
  67
  68   // These methods need to be synchronized since JDK DateFormat classes are not thread-safe
  69   // See issue 162
  70   public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
  71     synchronized (localFormat) {
  72       String dateFormatAsString = enUsFormat.format(src);
  73       return new JsonPrimitive(dateFormatAsString);
  74     }
  75   }
  76
  77   public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
  78       throws JsonParseException {
  79     if (!(json instanceof JsonPrimitive)) {
  80       throw new JsonParseException("The date should be a string value");
  81     }
  82     Date date = deserializeToDate(json);
  83     if (typeOfT == Date.class) {
  84       return date;
  85     } else if (typeOfT == Timestamp.class) {
  86       return new Timestamp(date.getTime());
  87     } else if (typeOfT == java.sql.Date.class) {
  88       return new java.sql.Date(date.getTime());
  89     } else {
  90       throw new IllegalArgumentException(getClass() + " cannot deserialize to " + typeOfT);
  91     }
  92   }
  93
  94   private Date deserializeToDate(JsonElement json) {
  95     synchronized (localFormat) {
  96       try {
  97         return localFormat.parse(json.getAsString());
  98       } catch (ParseException ignored) {
  99       }
 100       try {
 101         return enUsFormat.parse(json.getAsString());
 102       } catch (ParseException ignored) {
 103       }
 104       try {
 105         return iso8601Format.parse(json.getAsString());
 106       } catch (ParseException e) {
 107         throw new JsonSyntaxException(json.getAsString(), e);
 108       }
 109     }
 110   }
 111
 112   @Override
 113   public String toString() {
 114     StringBuilder sb = new StringBuilder();
 115     sb.append(DefaultDateTypeAdapter.class.getSimpleName());
 116     sb.append('(').append(localFormat.getClass().getSimpleName()).append(')');
 117     return sb.toString();
 118   }
 119 }