Java tutorial
package project.celine.infinitescroll.service; /** * Created by celine on 2015/10/26. */ /* * 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. */ 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; import java.util.Date; import java.util.Locale; import java.util.TimeZone; /** * 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 MyDateTypeAdapter extends TypeAdapter<Date> { public static final TypeAdapterFactory FACTORY = new TypeAdapterFactory() { @SuppressWarnings("unchecked") // we use a runtime check to make sure the 'T's equal public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) { return typeToken.getRawType() == Date.class ? (TypeAdapter<T>) new MyDateTypeAdapter() : null; } }; private static DateFormat buildNSDateFormat() { DateFormat nsFormat = new SimpleDateFormat("yyyy'-'MM'-'dd'T'HH':'mm':'ss.SSS'Z'", Locale.US); nsFormat.setTimeZone(TimeZone.getTimeZone("UTC")); return nsFormat; } private final DateFormat enUsFormat = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.US); private final DateFormat localFormat = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT); private final DateFormat iso8601Format = buildIso8601Format(); private final DateFormat nsdDateFormat = buildNSDateFormat(); private static DateFormat buildIso8601Format() { DateFormat iso8601Format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.US); iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC")); return iso8601Format; } @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) { try { return localFormat.parse(json); } catch (ParseException ignored) { } try { return enUsFormat.parse(json); } catch (ParseException ignored) { } try { return iso8601Format.parse(json); } catch (ParseException e) { } try { return nsdDateFormat.parse(json); } 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 = enUsFormat.format(value); out.value(dateFormatAsString); } }