Adds Charset serializer, also set as default serializer

With registration required == true, users still have to register
the required charsets, e.g. via `kryo.register(StandardCharsets.ISO_8859_1.getClass());`.

Resolves #364

src/com/esotericsoftware/kryo/Kryo.java

@@ -28,6 +28,7 @@
 import java.lang.reflect.Proxy;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Collection;
@@ -72,6 +73,7 @@
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.ByteSerializer;
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.CalendarSerializer;
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.CharSerializer;
+import com.esotericsoftware.kryo.serializers.DefaultSerializers.CharsetSerializer;
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.ClassSerializer;
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.CollectionsEmptyListSerializer;
 import com.esotericsoftware.kryo.serializers.DefaultSerializers.CollectionsEmptyMapSerializer;
@@ -213,6 +215,7 @@ public Kryo (ClassResolver classResolver, ReferenceResolver referenceResolver, S
 		addDefaultSerializer(TimeZone.class, TimeZoneSerializer.class);
 		addDefaultSerializer(Calendar.class, CalendarSerializer.class);
 		addDefaultSerializer(Locale.class, LocaleSerializer.class);
+		addDefaultSerializer(Charset.class, CharsetSerializer.class);
 		OptionalSerializers.addDefaultSerializers(this);
 		TimeSerializers.addDefaultSerializers(this);
 		lowPriorityDefaultSerializerCount = defaultSerializers.size();

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

@@ -15,12 +15,13 @@
  * SHALL THE COPYRIGHT HOLDER 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. */
-
+ * 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.esotericsoftware.kryo.serializers;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.nio.charset.Charset;
 import java.util.Calendar;
 import java.util.Collection;
 import java.util.Collections;
@@ -836,4 +837,20 @@ protected static boolean isSameLocale(Locale locale, String language, String cou
 			}
 		}
 	}
-}
+
+	/** Serializer for {@link Charset}. Added as default serializer for java >= 7. */
+	public static class CharsetSerializer extends Serializer<Charset> {
+
+		{ setImmutable(true); }
+
+		public void write(Kryo kryo, Output output, Charset object) {
+			output.writeString(object.name());
+		}
+
+		public Charset read(Kryo kryo, Input input, Class<Charset> type) {
+			return Charset.forName(input.readString());
+		}
+
+	}
+
+}

test/com/esotericsoftware/kryo/DefaultSerializersTest.java

@@ -15,22 +15,25 @@
  * SHALL THE COPYRIGHT HOLDER 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. */
-
+ * 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.esotericsoftware.kryo;
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Calendar;
 import java.util.Collections;
 import java.util.Date;
 import java.util.EnumSet;
+import java.util.List;
+import java.util.Locale;
 import java.util.TimeZone;
 
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
-import java.util.Locale;
 
 /** @author Nathan Sweet <misc@n4te.com> */
 public class DefaultSerializersTest extends KryoTestCase {
@@ -342,6 +345,26 @@ public void testLocaleSerializer () {
 		roundTrip(16, 16, new Locale("es", "ES", "áéíóú"));		
 	}
 
+	public void testCharset() {
+		List<String> css = Arrays.asList("ISO-8859-1", "US-ASCII", "UTF-8", "UTF-16", "UTF-16BE", "UTF-16LE");
+
+		for(String cs : css) {
+			Charset charset = Charset.forName(cs);
+			kryo.register(charset.getClass());
+			int expectedLength = 1 + cs.length();
+			roundTrip(expectedLength, expectedLength, charset);
+		}
+
+		kryo = new Kryo();
+		kryo.setRegistrationRequired(false);
+
+		for(String cs : css) {
+			Charset charset = Charset.forName(cs);
+			int expectedLength = 3 + charset.getClass().getName().length() + cs.length();
+			roundTrip(expectedLength, expectedLength, charset);
+		}
+	}
+
 	public enum TestEnum {
 		a, b, c
 	}
@@ -373,4 +396,4 @@ public BigIntegerSubclass(String val) {
 		}
 	}
 
-}
+}

test/com/esotericsoftware/kryo/SerializationCompatTest.java

@@ -22,6 +22,7 @@
 import com.esotericsoftware.kryo.SerializationCompatTestData.TestData;
 import com.esotericsoftware.kryo.SerializationCompatTestData.TestDataJava8;
 import com.esotericsoftware.kryo.io.*;
+import com.esotericsoftware.kryo.serializers.CollectionSerializer;
 import com.esotericsoftware.minlog.Log;
 import org.objenesis.strategy.StdInstantiatorStrategy;
 
@@ -32,6 +33,7 @@
 import java.lang.reflect.Field;
 import java.nio.ByteOrder;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.EnumSet;
 import java.util.List;
 
@@ -72,12 +74,12 @@ public class SerializationCompatTest extends KryoTestCase {
 
     private static final String ENDIANNESS = ByteOrder.nativeOrder() == ByteOrder.LITTLE_ENDIAN ? "le" : "be";
     private static final int JAVA_VERSION = Integer.parseInt(System.getProperty("java.version").split("\\.")[1]);
-    private static final int EXPECTED_DEFAULT_SERIALIZER_COUNT = JAVA_VERSION < 8 ? 33 : 51;
+    private static final int EXPECTED_DEFAULT_SERIALIZER_COUNT = JAVA_VERSION < 8 ? 34 : 52;
     private static final List<TestDataDescription<?>> TEST_DATAS = new ArrayList<TestDataDescription<?>>();
 
     static {
-        TEST_DATAS.add(new TestDataDescription<TestData>("3.0.0", new TestData(), 1646, 1754));
-        if(JAVA_VERSION >= 8) TEST_DATAS.add(new TestDataDescription<TestDataJava8>("3.1.0", new TestDataJava8(), 1806, 1958));
+        TEST_DATAS.add(new TestDataDescription<TestData>("3.0.0", new TestData(), 1824, 1932));
+        if(JAVA_VERSION >= 8) TEST_DATAS.add(new TestDataDescription<TestDataJava8>("3.1.0", new TestDataJava8(), 1984, 2136));
     };
 
     @Override
@@ -213,6 +215,7 @@ private void runTest(TestDataDescription description, String variant, Function1<
                 // if anything failed (e.g. the initial test), we should delete the file as it may be empty or corruped
                 out.close();
                 file.delete();
+                throw e;
             }
         }
     }

test/com/esotericsoftware/kryo/SerializationCompatTestData.java

@@ -26,6 +26,7 @@
 import java.io.Serializable;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.nio.charset.Charset;
 import java.time.*;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -112,6 +113,7 @@ public static class TestData implements Serializable {
 		private TimeZone _timeZone;
 		private Calendar _calendar;
 		private Locale _locale;
+		List<Charset> _charsets;
 
 		private Gender _enum;
 		private EnumSet<Gender> _enumSet;
@@ -184,6 +186,8 @@ public TestData () {
 
 			_timeZone = TimeZone.getTimeZone("America/Los_Angeles");
 			_locale = Locale.ENGLISH;
+			_charsets = new ArrayList<Charset>(Arrays.asList(Charset.forName("ISO-8859-1"), Charset.forName("US-ASCII"),
+					Charset.forName("UTF-8"), Charset.forName("UTF-16"), Charset.forName("UTF-16BE"), Charset.forName("UTF-16LE")));
 
 			_enum = Gender.FEMALE;
 			_enumSet = EnumSet.allOf(Gender.class);