forked from google/gson
/
DateTypeAdapter.java
101 lines (90 loc) · 3.5 KB
/
DateTypeAdapter.java
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/*
* 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.internal.JavaVersion;
import com.google.gson.internal.PreJava9DateFormatProvider;
import com.google.gson.internal.bind.util.ISO8601Utils;
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.ParsePosition;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
/**
* Adapter for 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 DateTypeAdapter extends TypeAdapter<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() == Date.class ? (TypeAdapter<T>) new DateTypeAdapter() : null;
}
};
/**
* List of 1 or more different date formats used for de-serialization attempts.
* The first of them (default US format) is used for serialization as well.
*/
private final List<DateFormat> dateFormats = new ArrayList<DateFormat>();
public DateTypeAdapter() {
dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.US));
if (!Locale.getDefault().equals(Locale.US)) {
dateFormats.add(DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT));
}
if (JavaVersion.isJava9OrLater()) {
dateFormats.add(PreJava9DateFormatProvider.getUSDateTimeFormat(DateFormat.DEFAULT, DateFormat.DEFAULT));
}
}
@Override public Date read(JsonReader in) throws IOException {
if (in.peek() == JsonToken.NULL) {
in.nextNull();
return null;
}
return deserializeToDate(in.nextString());
}
private synchronized Date deserializeToDate(String json) {
for (DateFormat dateFormat : dateFormats) {
try {
return dateFormat.parse(json);
} catch (ParseException ignored) {}
}
try {
return ISO8601Utils.parse(json, new ParsePosition(0));
} catch (ParseException e) {
throw new JsonSyntaxException(json, e);
}
}
@Override public synchronized void write(JsonWriter out, Date value) throws IOException {
if (value == null) {
out.nullValue();
return;
}
String dateFormatAsString = dateFormats.get(0).format(value);
out.value(dateFormatAsString);
}
}