Merge pull request #323 from kwon37xi/issue_321

Fix for #321 EnumNameSerializer

.gitignore

@@ -2,6 +2,8 @@
 *~
 .*.swp
 .DS_STORE
+*.iml
 
 bin/
 target/
+.idea/

src/com/esotericsoftware/kryo/serializers/EnumNameSerializer.java

@@ -0,0 +1,48 @@
+package com.esotericsoftware.kryo.serializers;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.KryoException;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+
+/**
+ * Enum serialize with enum's name.
+ * <p />
+ * This serializer prevents reading wrong values when enum's order changed.
+ *
+ * @author KwonNam Son <[email protected]>
+ */
+public class EnumNameSerializer extends Serializer<Enum> {
+	{
+		setImmutable(true);
+		setAcceptsNull(true);
+	}
+
+	private Class<? extends Enum> enumType;
+
+	public EnumNameSerializer(Class<? extends Enum> type) {
+		this.enumType = type;
+	}
+
+	public void write(Kryo kryo, Output output, Enum object) {
+		if (object == null) {
+			output.writeString(null);
+			return;
+		}
+		output.writeString(object.name());
+	}
+
+	public Enum read(Kryo kryo, Input input, Class<Enum> type) {
+		String name = input.readString();
+		if (name == null) {
+			return null;
+		}
+
+		try {
+			return Enum.valueOf(enumType, name);
+		} catch (IllegalArgumentException e) {
+			throw new KryoException("Invalid name for enum \"" + type.getName() + "\": " + name, e);
+		}
+	}
+}

test/com/esotericsoftware/kryo/serializers/EnumNameSerializerTest.java

@@ -0,0 +1,89 @@
+package com.esotericsoftware.kryo.serializers;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.KryoTestCase;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+
+import java.util.EnumSet;
+
+/**
+ * @author KwonNam Son <[email protected]>
+ */
+public class EnumNameSerializerTest extends KryoTestCase {
+
+	public void testEnumNameSerializer() {
+		kryo.addDefaultSerializer(Enum.class, EnumNameSerializer.class);
+		kryo.register(TestNameEnum.class);
+		kryo.register(TestAnotherNameEnum.class);
+
+		// 1 byte for identifying class name,
+		// rest bytes for enum's name
+		roundTrip(6, 6, TestNameEnum.HELLO);
+		roundTrip(5, 5, TestNameEnum.KRYO);
+
+		roundTrip(7, 7, TestAnotherNameEnum.SUNDAY);
+		roundTrip(8, 8, TestAnotherNameEnum.TUESDAY);
+
+		kryo = new Kryo();
+		kryo.addDefaultSerializer(Enum.class, EnumNameSerializer.class);
+		kryo.setRegistrationRequired(false);
+
+		roundTrip(83, 83, TestNameEnum.WORLD);
+		roundTrip(91, 91, TestAnotherNameEnum.MONDAY);
+	}
+
+	public void testEnumSetSerializerWithEnumNameSerializer() throws Exception {
+		kryo.addDefaultSerializer(Enum.class, EnumNameSerializer.class);
+		kryo.register(EnumSet.class);
+		kryo.register(TestNameEnum.class);
+
+		// roundTrip for EnumSet with EnumNameSerializer does not work.
+
+		// test directly
+		Output output = new Output(1024);
+		kryo.writeClassAndObject(output, EnumSet.of(TestNameEnum.HELLO, TestNameEnum.WORLD));
+		byte[] bytes = output.toBytes();
+
+		EnumSet<TestNameEnum> enumSet = (EnumSet<TestNameEnum>) kryo.readClassAndObject(new Input(bytes));
+		assertEquals(enumSet.size(), 2);
+		assertTrue(enumSet.contains(TestNameEnum.HELLO));
+		assertTrue(enumSet.contains(TestNameEnum.WORLD));
+		assertFalse(enumSet.contains(TestNameEnum.KRYO));
+
+		// empty EnumSet
+		roundTrip(3, 6, EnumSet.noneOf(TestNameEnum.class));
+
+	}
+
+	public void testEnumNameSerializerWithMethods() {
+		kryo.addDefaultSerializer(Enum.class, EnumNameSerializer.class);
+
+		kryo.register(TestNameEnumWithMethods.class);
+		roundTrip(6, 6, TestNameEnumWithMethods.ALPHA);
+		roundTrip(5, 5, TestNameEnumWithMethods.BETA);
+
+		kryo = new Kryo();
+		kryo.addDefaultSerializer(Enum.class, EnumNameSerializer.class);
+		kryo.setRegistrationRequired(false);
+
+		roundTrip(96, 96, TestNameEnumWithMethods.ALPHA);
+		roundTrip(95, 95, TestNameEnumWithMethods.BETA);
+
+	}
+
+	public enum TestNameEnum {
+		HELLO, KRYO, WORLD
+	}
+
+	public enum TestAnotherNameEnum {
+		SUNDAY, MONDAY, TUESDAY
+	}
+
+	public enum TestNameEnumWithMethods {
+		ALPHA {
+		},
+		BETA {
+		}
+	}
+}