Integrated internal changes from Google

12 files changed, 282 insertions, 65 deletions

diff --git a/java/core/src/main/java/com/google/protobuf/Android.java b/java/core/src/main/java/com/google/protobuf/Android.java
new file mode 100644
index 00000000..cad54783
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/Android.java
@@ -0,0 +1,57 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+final class Android {
+
+  private static final Class<?> MEMORY_CLASS = getClassForName("libcore.io.Memory");
+  private static final boolean IS_ROBOLECTRIC =
+      getClassForName("org.robolectric.Robolectric") != null;
+
+  /** Returns {@code true} if running on an Android device. */
+  static boolean isOnAndroidDevice() {
+    return MEMORY_CLASS != null && !IS_ROBOLECTRIC;
+  }
+
+  /** Returns the memory class or {@code null} if not on Android device. */
+  static Class<?> getMemoryClass() {
+    return MEMORY_CLASS;
+  }
+
+  @SuppressWarnings("unchecked")
+  private static <T> Class<T> getClassForName(String name) {
+    try {
+      return (Class<T>) Class.forName(name);
+    } catch (Throwable e) {
+      return null;
+    }
+  }
+}
diff --git a/java/core/src/main/java/com/google/protobuf/ByteString.java b/java/core/src/main/java/com/google/protobuf/ByteString.java
index 99a31209..d67bb54a 100644
--- a/java/core/src/main/java/com/google/protobuf/ByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/ByteString.java
@@ -124,14 +124,8 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
 
   private static final ByteArrayCopier byteArrayCopier;
   static {
-    boolean isAndroid = true;
-    try {
-      Class.forName("android.content.Context");
-    } catch (ClassNotFoundException e) {
-      isAndroid = false;
-    }
-
-    byteArrayCopier = isAndroid ? new SystemByteArrayCopier() : new ArraysByteArrayCopier();
+    byteArrayCopier =
+        Android.isOnAndroidDevice() ? new SystemByteArrayCopier() : new ArraysByteArrayCopier();
   }
 
   /**
diff --git a/java/core/src/main/java/com/google/protobuf/FieldSet.java b/java/core/src/main/java/com/google/protobuf/FieldSet.java
index 8a9239ed..c09daa32 100644
--- a/java/core/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
@@ -102,6 +102,11 @@ final class FieldSet<FieldDescriptorType extends
   @SuppressWarnings("rawtypes")
   private static final FieldSet DEFAULT_INSTANCE = new FieldSet(true);
 
+  /** Returns {@code true} if empty, {@code false} otherwise. */
+  boolean isEmpty() {
+    return fields.isEmpty();
+  }
+
   /** Make this FieldSet immutable from this point forward. */
   @SuppressWarnings("unchecked")
   public void makeImmutable() {
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 09084646..8b8d9fc6 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@@ -504,11 +504,8 @@ public abstract class GeneratedMessageLite<
             extends GeneratedMessageLite<MessageType, BuilderType>
             implements ExtendableMessageOrBuilder<MessageType, BuilderType> {
 
-    /**
-     * Represents the set of extensions on this message. For use by generated
-     * code only.
-     */
-    protected FieldSet<ExtensionDescriptor> extensions = FieldSet.newFieldSet();
+    /** Represents the set of extensions on this message. For use by generated code only. */
+    protected FieldSet<ExtensionDescriptor> extensions = FieldSet.emptySet();
 
     @SuppressWarnings("unchecked")
     protected final void mergeExtensionFields(final MessageType other) {
@@ -578,7 +575,11 @@ public abstract class GeneratedMessageLite<
       if (unknown) {  // Unknown field or wrong wire type.  Skip.
         return parseUnknownField(tag, input);
       }
-      
+
+      if (extensions.isImmutable()) {
+        extensions = extensions.clone();
+      }
+
       if (packed) {
         int length = input.readRawVarint32();
         int limit = input.pushLimit(length);
@@ -942,12 +943,6 @@ public abstract class GeneratedMessageLite<
       implements ExtendableMessageOrBuilder<MessageType, BuilderType> {
     protected ExtendableBuilder(MessageType defaultInstance) {
       super(defaultInstance);
-
-      // TODO(dweis): This is kind of an unnecessary clone since we construct a
-      //     new instance in the parent constructor which makes the extensions
-      //     immutable. This extra allocation shouldn't matter in practice
-      //     though.
-      instance.extensions = instance.extensions.clone();
     }
 
     // For immutable message conversion.
@@ -966,6 +961,15 @@ public abstract class GeneratedMessageLite<
       instance.extensions = instance.extensions.clone();
     }
 
+    private FieldSet<ExtensionDescriptor> ensureExtensionsAreMutable() {
+      FieldSet<ExtensionDescriptor> extensions = instance.extensions;
+      if (extensions.isImmutable()) {
+        extensions = extensions.clone();
+        instance.extensions = extensions;
+      }
+      return extensions;
+    }
+
     @Override
     public final MessageType buildPartial() {
       if (isBuilt) {
@@ -1024,7 +1028,8 @@ public abstract class GeneratedMessageLite<
 
       verifyExtensionContainingType(extensionLite);
       copyOnWrite();
-      instance.extensions.setField(extensionLite.descriptor, extensionLite.toFieldSetType(value));
+      ensureExtensionsAreMutable()
+          .setField(extensionLite.descriptor, extensionLite.toFieldSetType(value));
       return (BuilderType) this;
     }
 
@@ -1037,8 +1042,9 @@ public abstract class GeneratedMessageLite<
 
       verifyExtensionContainingType(extensionLite);
       copyOnWrite();
-      instance.extensions.setRepeatedField(
-          extensionLite.descriptor, index, extensionLite.singularToFieldSetType(value));
+      ensureExtensionsAreMutable()
+          .setRepeatedField(
+              extensionLite.descriptor, index, extensionLite.singularToFieldSetType(value));
       return (BuilderType) this;
     }
 
@@ -1051,8 +1057,8 @@ public abstract class GeneratedMessageLite<
 
       verifyExtensionContainingType(extensionLite);
       copyOnWrite();
-      instance.extensions.addRepeatedField(
-          extensionLite.descriptor, extensionLite.singularToFieldSetType(value));
+      ensureExtensionsAreMutable()
+          .addRepeatedField(extensionLite.descriptor, extensionLite.singularToFieldSetType(value));
       return (BuilderType) this;
     }
 
@@ -1063,7 +1069,7 @@ public abstract class GeneratedMessageLite<
 
       verifyExtensionContainingType(extensionLite);
       copyOnWrite();
-      instance.extensions.clearField(extensionLite.descriptor);
+      ensureExtensionsAreMutable().clearField(extensionLite.descriptor);
       return (BuilderType) this;
     }
   }
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormat.java b/java/core/src/main/java/com/google/protobuf/TextFormat.java
index ab9acf2f..0c8b898c 100644
--- a/java/core/src/main/java/com/google/protobuf/TextFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormat.java
@@ -1224,6 +1224,22 @@ public final class TextFormat {
   }
 
   /**
+   * Parse a text-format message from {@code input}.
+   *
+   * @return the parsed message, guaranteed initialized
+   */
+  public static <T extends Message> T parse(final CharSequence input,
+                                            final Class<T> protoClass)
+                                            throws ParseException {
+    Message.Builder builder =
+        Internal.getDefaultInstance(protoClass).newBuilderForType();
+    merge(input, builder);
+    @SuppressWarnings("unchecked")
+    T output = (T) builder.build();
+    return output;
+  }
+
+  /**
    * Parse a text-format message from {@code input} and merge the contents
    * into {@code builder}.  Extensions will be recognized if they are
    * registered in {@code extensionRegistry}.
@@ -1248,6 +1264,25 @@ public final class TextFormat {
     PARSER.merge(input, extensionRegistry, builder);
   }
 
+  /**
+   * Parse a text-format message from {@code input}.  Extensions will be
+   * recognized if they are registered in {@code extensionRegistry}.
+   *
+   * @return the parsed message, guaranteed initialized
+   */
+  public static <T extends Message> T parse(
+      final CharSequence input,
+      final ExtensionRegistry extensionRegistry,
+      final Class<T> protoClass)
+      throws ParseException {
+    Message.Builder builder =
+        Internal.getDefaultInstance(protoClass).newBuilderForType();
+    merge(input, extensionRegistry, builder);
+    @SuppressWarnings("unchecked")
+    T output = (T) builder.build();
+    return output;
+  }
+
 
   /**
    * Parser for text-format proto2 instances. This class is thread-safe.
diff --git a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
index 88315cb6..98c93b90 100644
--- a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
@@ -364,15 +364,6 @@ final class UnsafeUtil {
   }
 
 
-  @SuppressWarnings("unchecked")
-  private static <T> Class<T> getClassForName(String name) {
-    try {
-      return (Class<T>) Class.forName(name);
-    } catch (Throwable e) {
-      return null;
-    }
-  }
-
   /** Finds the address field within a direct {@link Buffer}. */
   private static Field bufferAddressField() {
     return field(Buffer.class, "address");
diff --git a/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
index 622e36a4..cb2d34eb 100644
--- a/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
@@ -30,6 +30,9 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.TestUtil.TEST_REQUIRED_INITIALIZED;
+import static com.google.protobuf.TestUtil.TEST_REQUIRED_UNINITIALIZED;
+
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import protobuf_unittest.UnittestOptimizeFor.TestOptimizedForSize;
 import protobuf_unittest.UnittestProto;
@@ -346,11 +349,6 @@ public class AbstractMessageTest extends TestCase {
   // -----------------------------------------------------------------
   // Tests for isInitialized().
 
-  private static final TestRequired TEST_REQUIRED_UNINITIALIZED =
-    TestRequired.getDefaultInstance();
-  private static final TestRequired TEST_REQUIRED_INITIALIZED =
-    TestRequired.newBuilder().setA(1).setB(2).setC(3).build();
-
   public void testIsInitialized() throws Exception {
     TestRequired.Builder builder = TestRequired.newBuilder();
     AbstractMessageWrapper.Builder abstractBuilder =
@@ -380,7 +378,7 @@ public class AbstractMessageTest extends TestCase {
     builder.setOptionalMessage(TEST_REQUIRED_UNINITIALIZED);
     assertFalse(abstractBuilder.isInitialized());
     assertEquals(
-        "optional_message.a, optional_message.b, optional_message.c",
+        "optional_message.b, optional_message.c",
         abstractBuilder.getInitializationErrorString());
 
     builder.setOptionalMessage(TEST_REQUIRED_INITIALIZED);
@@ -390,7 +388,7 @@ public class AbstractMessageTest extends TestCase {
     builder.addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED);
     assertFalse(abstractBuilder.isInitialized());
     assertEquals(
-        "repeated_message[0].a, repeated_message[0].b, repeated_message[0].c",
+        "repeated_message[0].b, repeated_message[0].c",
         abstractBuilder.getInitializationErrorString());
 
     builder.setRepeatedMessage(0, TEST_REQUIRED_INITIALIZED);
diff --git a/java/core/src/test/java/com/google/protobuf/TestUtil.java b/java/core/src/test/java/com/google/protobuf/TestUtil.java
index e96adf07..b4bc3a3d 100644
--- a/java/core/src/test/java/com/google/protobuf/TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/TestUtil.java
@@ -231,6 +231,7 @@ import protobuf_unittest.UnittestProto.TestAllTypesOrBuilder;
 import protobuf_unittest.UnittestProto.TestOneof2;
 import protobuf_unittest.UnittestProto.TestPackedExtensions;
 import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestRequired;
 import protobuf_unittest.UnittestProto.TestUnpackedTypes;
 import java.io.File;
 import java.io.IOException;
@@ -252,6 +253,11 @@ import junit.framework.Assert;
 public final class TestUtil {
   private TestUtil() {}
 
+  public static final TestRequired TEST_REQUIRED_UNINITIALIZED =
+      TestRequired.newBuilder().setA(1).buildPartial();
+  public static final TestRequired TEST_REQUIRED_INITIALIZED =
+      TestRequired.newBuilder().setA(1).setB(2).setC(3).build();
+
   /** Helper to convert a String to ByteString. */
   static ByteString toBytes(String str) {
     return ByteString.copyFrom(str.getBytes(Internal.UTF_8));
diff --git a/java/core/src/test/java/com/google/protobuf/TextFormatTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
index 28c4fdea..5d38ca51 100644
--- a/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
@@ -30,6 +30,9 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.TestUtil.TEST_REQUIRED_INITIALIZED;
+import static com.google.protobuf.TestUtil.TEST_REQUIRED_UNINITIALIZED;
+
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.TextFormat.Parser.SingularOverwritePolicy;
@@ -42,6 +45,7 @@ import protobuf_unittest.UnittestProto.TestAllTypes;
 import protobuf_unittest.UnittestProto.TestAllTypes.NestedMessage;
 import protobuf_unittest.UnittestProto.TestEmptyMessage;
 import protobuf_unittest.UnittestProto.TestOneof2;
+import protobuf_unittest.UnittestProto.TestRequired;
 import proto2_wireformat_unittest.UnittestMsetWireFormat.TestMessageSet;
 import java.io.StringReader;
 import java.util.List;
@@ -326,19 +330,58 @@ public class TextFormatTest extends TestCase {
 
   // =================================================================
 
-  public void testParse() throws Exception {
+  public void testMerge() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(allFieldsSetText, builder);
     TestUtil.assertAllFieldsSet(builder.build());
   }
 
-  public void testParseReader() throws Exception {
+  public void testParse() throws Exception {
+    TestUtil.assertAllFieldsSet(
+        TextFormat.parse(allFieldsSetText, TestAllTypes.class));
+  }
+
+  public void testMergeInitialized() throws Exception {
+    TestRequired.Builder builder = TestRequired.newBuilder();
+    TextFormat.merge(TEST_REQUIRED_INITIALIZED.toString(), builder);
+    assertEquals(TEST_REQUIRED_INITIALIZED.toString(),
+                 builder.buildPartial().toString());
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testParseInitialized() throws Exception {
+    TestRequired parsed =
+        TextFormat.parse(TEST_REQUIRED_INITIALIZED.toString(),
+                         TestRequired.class);
+    assertEquals(TEST_REQUIRED_INITIALIZED.toString(), parsed.toString());
+    assertTrue(parsed.isInitialized());
+  }
+
+  public void testMergeUninitialized() throws Exception {
+    TestRequired.Builder builder = TestRequired.newBuilder();
+    TextFormat.merge(TEST_REQUIRED_UNINITIALIZED.toString(), builder);
+    assertEquals(TEST_REQUIRED_UNINITIALIZED.toString(),
+                 builder.buildPartial().toString());
+    assertFalse(builder.isInitialized());
+  }
+
+  public void testParseUninitialized() throws Exception {
+    try {
+      TextFormat.parse(TEST_REQUIRED_UNINITIALIZED.toString(),
+                       TestRequired.class);
+      fail("Expected UninitializedMessageException.");
+    } catch (UninitializedMessageException e) {
+      assertEquals("Message missing required fields: b, c", e.getMessage());
+    }
+  }
+
+  public void testMergeReader() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(new StringReader(allFieldsSetText), builder);
     TestUtil.assertAllFieldsSet(builder.build());
   }
 
-  public void testParseExtensions() throws Exception {
+  public void testMergeExtensions() throws Exception {
     TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
     TextFormat.merge(allExtensionsSetText,
                      TestUtil.getExtensionRegistry(),
@@ -346,7 +389,14 @@ public class TextFormatTest extends TestCase {
     TestUtil.assertAllExtensionsSet(builder.build());
   }
 
-  public void testParseCompatibility() throws Exception {
+  public void testParseExtensions() throws Exception {
+    TestUtil.assertAllExtensionsSet(
+        TextFormat.parse(allExtensionsSetText,
+                         TestUtil.getExtensionRegistry(),
+                         TestAllExtensions.class));
+  }
+
+  public void testMergeAndParseCompatibility() throws Exception {
     String original = "repeated_float: inf\n" +
                       "repeated_float: -inf\n" +
                       "repeated_float: nan\n" +
@@ -371,21 +421,29 @@ public class TextFormatTest extends TestCase {
                         "repeated_double: Infinity\n" +
                         "repeated_double: -Infinity\n" +
                         "repeated_double: NaN\n";
+
+    // Test merge().
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(original, builder);
     assertEquals(canonical, builder.build().toString());
+
+    // Test parse().
+    assertEquals(canonical,
+                 TextFormat.parse(original, TestAllTypes.class).toString());
   }
 
-  public void testParseExotic() throws Exception {
+  public void testMergeAndParseExotic() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(exoticText, builder);
 
     // Too lazy to check things individually.  Don't try to debug this
     // if testPrintExotic() is failing.
     assertEquals(canonicalExoticText, builder.build().toString());
+    assertEquals(canonicalExoticText,
+                 TextFormat.parse(exoticText, TestAllTypes.class).toString());
   }
 
-  public void testParseMessageSet() throws Exception {
+  public void testMergeMessageSet() throws Exception {
     ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
     extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
     extensionRegistry.add(TestMessageSetExtension2.messageSetExtension);
@@ -411,7 +469,7 @@ public class TextFormatTest extends TestCase {
       TestMessageSetExtension1.messageSetExtension).getI());
   }
 
-  public void testParseMessageSetWithOverwriteForbidden() throws Exception {
+  public void testMergeMessageSetWithOverwriteForbidden() throws Exception {
     ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
     extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
     extensionRegistry.add(TestMessageSetExtension2.messageSetExtension);
@@ -438,20 +496,20 @@ public class TextFormatTest extends TestCase {
     }
   }
 
-  public void testParseNumericEnum() throws Exception {
+  public void testMergeNumericEnum() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge("optional_nested_enum: 2", builder);
     assertEquals(TestAllTypes.NestedEnum.BAR, builder.getOptionalNestedEnum());
   }
 
-  public void testParseAngleBrackets() throws Exception {
+  public void testMergeAngleBrackets() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge("OptionalGroup: < a: 1 >", builder);
     assertTrue(builder.hasOptionalGroup());
     assertEquals(1, builder.getOptionalGroup().getA());
   }
 
-  public void testParseComment() throws Exception {
+  public void testMergeComment() throws Exception {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     TextFormat.merge(
       "# this is a comment\n" +
@@ -463,6 +521,7 @@ public class TextFormatTest extends TestCase {
   }
 
   private void assertParseError(String error, String text) {
+    // Test merge().
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     try {
       TextFormat.merge(text, TestUtil.getExtensionRegistry(), builder);
@@ -470,6 +529,15 @@ public class TextFormatTest extends TestCase {
     } catch (TextFormat.ParseException e) {
       assertEquals(error, e.getMessage());
     }
+
+    // Test parse().
+    try {
+      TextFormat.parse(
+          text, TestUtil.getExtensionRegistry(), TestAllTypes.class);
+      fail("Expected parse exception.");
+    } catch (TextFormat.ParseException e) {
+      assertEquals(error, e.getMessage());
+    }
   }
 
 
diff --git a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
index a26dbc2d..7f69ee68 100644
--- a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
+++ b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
@@ -105,7 +105,7 @@ public class JsonFormat {
   public static Printer printer() {
     return new Printer(
         TypeRegistry.getEmptyTypeRegistry(), false, Collections.<FieldDescriptor>emptySet(),
-        false, false);
+        false, false, false);
   }
 
   /**
@@ -125,18 +125,21 @@ public class JsonFormat {
     private Set<FieldDescriptor> includingDefaultValueFields;
     private final boolean preservingProtoFieldNames;
     private final boolean omittingInsignificantWhitespace;
+    private final boolean printingEnumsAsInts;
 
     private Printer(
         TypeRegistry registry,
         boolean alwaysOutputDefaultValueFields,
         Set<FieldDescriptor> includingDefaultValueFields,
         boolean preservingProtoFieldNames,
-        boolean omittingInsignificantWhitespace) {
+        boolean omittingInsignificantWhitespace,
+        boolean printingEnumsAsInts) {
       this.registry = registry;
       this.alwaysOutputDefaultValueFields = alwaysOutputDefaultValueFields;
       this.includingDefaultValueFields = includingDefaultValueFields;
       this.preservingProtoFieldNames = preservingProtoFieldNames;
       this.omittingInsignificantWhitespace = omittingInsignificantWhitespace;
+      this.printingEnumsAsInts = printingEnumsAsInts;
     }
 
     /**
@@ -154,7 +157,8 @@ public class JsonFormat {
           alwaysOutputDefaultValueFields,
           includingDefaultValueFields,
           preservingProtoFieldNames,
-          omittingInsignificantWhitespace);
+          omittingInsignificantWhitespace,
+          printingEnumsAsInts);
     }
 
     /**
@@ -170,7 +174,31 @@ public class JsonFormat {
           true,
           Collections.<FieldDescriptor>emptySet(),
           preservingProtoFieldNames,
-          omittingInsignificantWhitespace);
+          omittingInsignificantWhitespace,
+          printingEnumsAsInts);
+    }
+
+    /**
+     * Creates a new {@link Printer} that will print enum field values as integers instead of as
+     * string.
+     * The new Printer clones all other configurations from the current
+     * {@link Printer}.
+     */
+    public Printer printingEnumsAsInts() {
+      checkUnsetPrintingEnumsAsInts();
+      return new Printer(
+          registry,
+          alwaysOutputDefaultValueFields,
+          Collections.<FieldDescriptor>emptySet(),
+          preservingProtoFieldNames,
+          omittingInsignificantWhitespace,
+          true);
+    }
+
+    private void checkUnsetPrintingEnumsAsInts() {
+      if (printingEnumsAsInts) {
+        throw new IllegalStateException("JsonFormat printingEnumsAsInts has already been set.");
+      }
     }
 
     /**
@@ -191,7 +219,8 @@ public class JsonFormat {
           false,
           fieldsToAlwaysOutput,
           preservingProtoFieldNames,
-          omittingInsignificantWhitespace);
+          omittingInsignificantWhitespace,
+          printingEnumsAsInts);
     }
 
     private void checkUnsetIncludingDefaultValueFields() {
@@ -213,7 +242,8 @@ public class JsonFormat {
           alwaysOutputDefaultValueFields,
           includingDefaultValueFields,
           true,
-          omittingInsignificantWhitespace);
+          omittingInsignificantWhitespace,
+          printingEnumsAsInts);
     }
 
 
@@ -240,7 +270,8 @@ public class JsonFormat {
           alwaysOutputDefaultValueFields,
           includingDefaultValueFields,
           preservingProtoFieldNames,
-          true);
+          true,
+          printingEnumsAsInts);
     }
 
     /**
@@ -259,7 +290,8 @@ public class JsonFormat {
               includingDefaultValueFields,
               preservingProtoFieldNames,
               output,
-              omittingInsignificantWhitespace)
+              omittingInsignificantWhitespace,
+              printingEnumsAsInts)
           .print(message);
     }
 
@@ -416,7 +448,7 @@ public class JsonFormat {
        */
       public Builder add(Iterable<Descriptor> messageTypes) {
         if (types == null) {
-          throw new IllegalStateException("A TypeRegistry.Builer can only be used once.");
+          throw new IllegalStateException("A TypeRegistry.Builder can only be used once.");
         }
         for (Descriptor type : messageTypes) {
           addFile(type.getFile());
@@ -570,6 +602,7 @@ public class JsonFormat {
     private final boolean alwaysOutputDefaultValueFields;
     private final Set<FieldDescriptor> includingDefaultValueFields;
     private final boolean preservingProtoFieldNames;
+    private final boolean printingEnumsAsInts;
     private final TextGenerator generator;
     // We use Gson to help handle string escapes.
     private final Gson gson;
@@ -586,11 +619,13 @@ public class JsonFormat {
         Set<FieldDescriptor> includingDefaultValueFields,
         boolean preservingProtoFieldNames,
         Appendable jsonOutput,
-        boolean omittingInsignificantWhitespace) {
+        boolean omittingInsignificantWhitespace,
+        boolean printingEnumsAsInts) {
       this.registry = registry;
       this.alwaysOutputDefaultValueFields = alwaysOutputDefaultValueFields;
       this.includingDefaultValueFields = includingDefaultValueFields;
       this.preservingProtoFieldNames = preservingProtoFieldNames;
+      this.printingEnumsAsInts = printingEnumsAsInts;
       this.gson = GsonHolder.DEFAULT_GSON;
       // json format related properties, determined by printerType
       if (omittingInsignificantWhitespace) {
@@ -1069,7 +1104,7 @@ public class JsonFormat {
               generator.print("\"");
             }
           } else {
-            if (((EnumValueDescriptor) value).getIndex() == -1) {
+            if (printingEnumsAsInts || ((EnumValueDescriptor) value).getIndex() == -1) {
               generator.print(String.valueOf(((EnumValueDescriptor) value).getNumber()));
             } else {
               generator.print("\"" + ((EnumValueDescriptor) value).getName() + "\"");
diff --git a/java/util/src/main/java/com/google/protobuf/util/Timestamps.java b/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
index 7a1f2014..9e528d4a 100644
--- a/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
+++ b/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
@@ -74,6 +74,11 @@ public final class Timestamps {
   public static final Timestamp MAX_VALUE =
       Timestamp.newBuilder().setSeconds(TIMESTAMP_SECONDS_MAX).setNanos(999999999).build();
 
+  /**
+   * A constant holding the {@link Timestamp} of epoch time, {@code 1970-01-01T00:00:00.000000000Z}.
+   */
+  public static final Timestamp EPOCH = Timestamp.newBuilder().setSeconds(0).setNanos(0).build();
+
   private static final ThreadLocal<SimpleDateFormat> timestampFormat =
       new ThreadLocal<SimpleDateFormat>() {
         @Override
@@ -358,10 +363,12 @@ public final class Timestamps {
   static Timestamp normalizedTimestamp(long seconds, int nanos) {
     if (nanos <= -NANOS_PER_SECOND || nanos >= NANOS_PER_SECOND) {
       seconds = checkedAdd(seconds, nanos / NANOS_PER_SECOND);
-      nanos %= NANOS_PER_SECOND;
+      nanos = (int) (nanos % NANOS_PER_SECOND);
     }
     if (nanos < 0) {
-      nanos += NANOS_PER_SECOND; // no overflow since nanos is negative (and we're adding)
+      nanos =
+          (int)
+              (nanos + NANOS_PER_SECOND); // no overflow since nanos is negative (and we're adding)
       seconds = checkedSubtract(seconds, 1);
     }
     Timestamp timestamp = Timestamp.newBuilder().setSeconds(seconds).setNanos(nanos).build();
diff --git a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
index e4c5387a..6ef08508 100644
--- a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
@@ -1174,6 +1174,14 @@ public class JsonFormatTest extends TestCase {
     JsonFormat.parser().ignoringUnknownFields().merge(json, builder);
   }
 
+  public void testParserIntegerEnumValue() throws Exception {
+    TestAllTypes.Builder actualBuilder = TestAllTypes.newBuilder();
+    mergeFromJson("{\n" + "  \"optionalNestedEnum\": 2\n" + "}", actualBuilder);
+
+    TestAllTypes expected = TestAllTypes.newBuilder().setOptionalNestedEnum(NestedEnum.BAZ).build();
+    assertEquals(expected, actualBuilder.build());
+  }
+
   public void testCustomJsonName() throws Exception {
     TestCustomJsonName message = TestCustomJsonName.newBuilder().setValue(12345).build();
     assertEquals("{\n" + "  \"@value\": 12345\n" + "}", JsonFormat.printer().print(message));
@@ -1441,6 +1449,13 @@ public class JsonFormatTest extends TestCase {
     assertEquals(54321, builder.getOptionalInt32());
   }
 
+  public void testPrintingEnumsAsInts() throws Exception {
+    TestAllTypes message = TestAllTypes.newBuilder().setOptionalNestedEnum(NestedEnum.BAR).build();
+    assertEquals(
+        "{\n" + "  \"optionalNestedEnum\": 1\n" + "}",
+        JsonFormat.printer().printingEnumsAsInts().print(message));
+  }
+
   public void testOmittingInsignificantWhiteSpace() throws Exception {
     TestAllTypes message = TestAllTypes.newBuilder().setOptionalInt32(12345).build();
     assertEquals(