QueriesLearningTest

CalendarUtil.java

public final class CalendarUtil {

  @SuppressWarnings("unused")
  CalendarUtil() {
  }

  public static Date january(int year, int day) {
    return newDate(year, 1, day);
  }

  public static Date february(int year, int day) {
    return newDate(year, 2, day);
  }

  public static Date newDate(int year, int month, int day) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.MONTH, month - 1);
    calendar.set(Calendar.DAY_OF_MONTH, day);
    calendar.set(Calendar.HOUR, 1);
    calendar.set(Calendar.MINUTE, 1);
    calendar.set(Calendar.SECOND, 1);

    clearNonDateFields(calendar);
    return calendar.getTime();
  }

   private static Calendar clearNonDateFields(Calendar c) {
    c.clear(Calendar.HOUR);
    c.clear(Calendar.MINUTE);
    c.clear(Calendar.SECOND);
    c.clear(Calendar.MILLISECOND);
    return c;
  }
}

QueriesLearningTest.java

public class QueriesLearningTest {

  @Rule
  public DatastoreRule rule = new DatastoreRule();

  @Test
  public void learnToUseConditionalQueries() {

    DatastoreService dss = DatastoreServiceFactory.getDatastoreService();

    insert(january(2012, 10));
    insert(january(2012, 11));
    insert(january(2012, 12));
    insert(january(2012, 20));

    Query query = new Query("Test");
    query.addFilter("date", FilterOperator.GREATER_THAN_OR_EQUAL, january(2012,10));
    query.addFilter("date", FilterOperator.LESS_THAN_OR_EQUAL, january(2012, 15));

    List<Entity> entities = Lists.newArrayList(dss.prepare(query).asIterable());
    assertThat(entities.size(),is(equalTo(3)));
  }

  private void insert(Date date) {
    Entity entity = new Entity("Test");
    entity.setProperty("date", date);
    DatastoreService dss = DatastoreServiceFactory.getDatastoreService();
    dss.put(entity);
  }
}