Adding Timestamp.toDate().

schmidt-sebastian · schmidt-sebastian · commit 4cdaf68bc8da · 2018-05-25T15:26:56.000-07:00
This will be used by consumers of the Firestore API.
diff --git a/google-cloud-clients/google-cloud-core/src/main/java/com/google/cloud/Timestamp.java b/google-cloud-clients/google-cloud-core/src/main/java/com/google/cloud/Timestamp.java
@@ -95,6 +95,18 @@ public static Timestamp of(Date date) {
     return ofTimeMicroseconds(TimeUnit.MILLISECONDS.toMicros(date.getTime()));
   }
 
+  /**
+   * Returns a new {@code java.util.Date} corresponding to this {@code timestamp}. Any
+   * sub-millisecond precision will be stripped.
+   *
+   * @return An approximate {@code java.util.Date} representation of this {@code timestamp}.
+   */
+  public Date toDate() {
+    long secondsInMilliseconds = TimeUnit.SECONDS.toMillis(this.seconds);
+    long nanosInMilliseconds = TimeUnit.NANOSECONDS.toMillis(this.nanos);
+    return new Date(secondsInMilliseconds + nanosInMilliseconds);
+  }
+
   /** Creates an instance with current time. */
   public static Timestamp now() {
     java.sql.Timestamp date = new java.sql.Timestamp(System.currentTimeMillis());
diff --git a/google-cloud-clients/google-cloud-core/src/test/java/com/google/cloud/TimestampTest.java b/google-cloud-clients/google-cloud-core/src/test/java/com/google/cloud/TimestampTest.java
@@ -21,8 +21,10 @@
 
 import com.google.common.testing.EqualsTester;
 import java.util.Calendar;
+import java.util.Date;
 import java.util.GregorianCalendar;
 import java.util.TimeZone;
+import java.util.concurrent.TimeUnit;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -35,6 +37,9 @@ public class TimestampTest {
   private static final String TEST_TIME_ISO = "2015-10-12T15:14:54Z";
   private static final long TEST_TIME_SECONDS = 1444662894L;
   private static final long TEST_TIME_MICROSECONDS = 10000100L;
+  private static final long TEST_TIME_MILLISECONDS =
+      TimeUnit.SECONDS.toMillis(1444662894L) + TimeUnit.MICROSECONDS.toMillis(1234);
+  private static final Date TEST_DATE = new Date(TEST_TIME_MILLISECONDS);
 
   @Rule public ExpectedException expectedException = ExpectedException.none();
 
@@ -64,6 +69,24 @@ public void ofMicroseconds() {
     assertThat(timestamp.getNanos()).isEqualTo(TEST_TIME_MICROSECONDS % 1000000L * 1000);
   }
 
+  @Test
+  public void ofDate() {
+    Timestamp timestamp = Timestamp.of(TEST_DATE);
+    Long expectedSeconds = TimeUnit.MILLISECONDS.toSeconds(TEST_TIME_MILLISECONDS);
+    Long expectedNanos =
+        TimeUnit.MILLISECONDS.toNanos(TEST_TIME_MILLISECONDS)
+            - TimeUnit.SECONDS.toNanos(expectedSeconds);
+    assertThat(timestamp.getSeconds()).isEqualTo(expectedSeconds);
+    assertThat(timestamp.getNanos()).isEqualTo(expectedNanos);
+  }
+
+  @Test
+  public void toDate() {
+    Timestamp timestamp = Timestamp.ofTimeSecondsAndNanos(TEST_TIME_SECONDS, 1234 * 1000);
+    Date date = timestamp.toDate();
+    assertThat(TEST_TIME_MILLISECONDS).isEqualTo(date.getTime());
+  }
+
   @Test
   public void toFromSqlTimestamp() {
     long seconds = TEST_TIME_SECONDS;
