gson-comments/extras/src/test/java/com/google/gson/typeadapters/UtcDateTypeAdapterTest.java

/*
 * 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.typeadapters;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import org.junit.Test;

@SuppressWarnings("JavaUtilDate")
public final class UtcDateTypeAdapterTest {
  private final Gson gson = new GsonBuilder()
    .registerTypeAdapter(Date.class, new UtcDateTypeAdapter())
    .create();

  @Test
  public void testLocalTimeZone() {
    Date expected = new Date();
    String json = gson.toJson(expected);
    Date actual = gson.fromJson(json, Date.class);
    assertEquals(expected.getTime(), actual.getTime());
  }

  @Test
  public void testDifferentTimeZones() {
    for (String timeZone : TimeZone.getAvailableIDs()) {
      Calendar cal = Calendar.getInstance(TimeZone.getTimeZone(timeZone));
      Date expected = cal.getTime();
      String json = gson.toJson(expected);
      // System.out.println(json + ": " + timeZone);
      Date actual = gson.fromJson(json, Date.class);
      assertEquals(expected.getTime(), actual.getTime());
    }
  }

  /**
   * JDK 1.7 introduced support for XXX format to indicate UTC date. But Android is older JDK.
   * We want to make sure that this date is parseable in Android.
   */
  @Test
  public void testUtcDatesOnJdkBefore1_7() {
    Gson gson = new GsonBuilder()
      .registerTypeAdapter(Date.class, new UtcDateTypeAdapter())
      .create();
    gson.fromJson("'2014-12-05T04:00:00.000Z'", Date.class);
  }

  @Test
  public void testUtcWithJdk7Default() {
    Date expected = new Date();
    SimpleDateFormat iso8601Format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX", Locale.US);
    iso8601Format.setTimeZone(TimeZone.getTimeZone("UTC"));
    String expectedJson = "\"" + iso8601Format.format(expected) + "\"";
    String actualJson = gson.toJson(expected);
    assertEquals(expectedJson, actualJson);
    Date actual = gson.fromJson(expectedJson, Date.class);
    assertEquals(expected.getTime(), actual.getTime());
  }

  @Test
  public void testNullDateSerialization() {
    String json = gson.toJson(null, Date.class);
    assertEquals("null", json);
  }

  @Test
  public void testWellFormedParseException() {
    try {
      gson.fromJson("2017-06-20T14:32:30", Date.class);
      fail("No exception");
    } catch (JsonParseException exe) {
      assertEquals("java.text.ParseException: Failed to parse date ['2017-06-20T14']: 2017-06-20T14", exe.getMessage());
    }
  }
}