Fix EsotericSoftware#412: Add default serializer for java.net.URL

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.net.URL;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Calendar;
@@ -43,6 +44,7 @@
 import java.util.TreeMap;
 import java.util.TreeSet;
 
+import com.esotericsoftware.kryo.serializers.DefaultSerializers.URLSerializer;
 import com.esotericsoftware.kryo.serializers.OptionalSerializers;
 import com.esotericsoftware.kryo.serializers.GenericsResolver;
 import com.esotericsoftware.kryo.serializers.TimeSerializers;
@@ -216,6 +218,7 @@ public Kryo (ClassResolver classResolver, ReferenceResolver referenceResolver, S
 		addDefaultSerializer(Calendar.class, CalendarSerializer.class);
 		addDefaultSerializer(Locale.class, LocaleSerializer.class);
 		addDefaultSerializer(Charset.class, CharsetSerializer.class);
+		addDefaultSerializer(URL.class, URLSerializer.class);
 		OptionalSerializers.addDefaultSerializers(this);
 		TimeSerializers.addDefaultSerializers(this);
 		lowPriorityDefaultSerializerCount = defaultSerializers.size();

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

@@ -21,6 +21,8 @@
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.Calendar;
 import java.util.Collection;
@@ -838,7 +840,7 @@ protected static boolean isSameLocale(Locale locale, String language, String cou
 		}
 	}
 
-	/** Serializer for {@link Charset}. Added as default serializer for java >= 7. */
+	/** Serializer for {@link Charset}. */
 	public static class CharsetSerializer extends Serializer<Charset> {
 
 		{ setImmutable(true); }
@@ -853,4 +855,23 @@ public Charset read(Kryo kryo, Input input, Class<Charset> type) {
 
 	}
 
+	/** Serializer for {@link URL}. */
+	public static class URLSerializer extends Serializer<URL> {
+
+		{ setImmutable(true); }
+
+		public void write(Kryo kryo, Output output, URL object) {
+			output.writeString(object.toExternalForm());
+		}
+
+		public URL read(Kryo kryo, Input input, Class<URL> type) {
+			try {
+				return new java.net.URL(input.readString());
+			} catch (MalformedURLException e) {
+				throw new KryoException(e);
+			}
+		}
+
+	}
+
 }

test/com/esotericsoftware/kryo/DefaultSerializersTest.java

@@ -21,6 +21,7 @@
 
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.net.URL;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -34,6 +35,7 @@
 
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
+import org.objenesis.strategy.StdInstantiatorStrategy;
 
 /** @author Nathan Sweet <[email protected]> */
 public class DefaultSerializersTest extends KryoTestCase {
@@ -365,6 +367,15 @@ public void testCharset() {
 		}
 	}
 
+	public void testURLSerializer () throws Exception {
+		kryo.setInstantiatorStrategy(new Kryo.DefaultInstantiatorStrategy(new StdInstantiatorStrategy()));
+		kryo.setRegistrationRequired(true);
+		kryo.register(URL.class);
+
+		roundTrip(41, 41, new URL("https://github.com/EsotericSoftware/kryo"));
+		roundTrip(78, 78, new URL("https://github.com:443/EsotericSoftware/kryo/pulls?utf8=%E2%9C%93&q=is%3Apr"));
+	}
+
 	public enum TestEnum {
 		a, b, c
 	}

test/com/esotericsoftware/kryo/SerializationCompatTest.java

@@ -74,12 +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 ? 34 : 52;
+    private static final int EXPECTED_DEFAULT_SERIALIZER_COUNT = JAVA_VERSION < 8 ? 35 : 53;
     private static final List<TestDataDescription<?>> TEST_DATAS = new ArrayList<TestDataDescription<?>>();
 
     static {
-        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));
+        TEST_DATAS.add(new TestDataDescription<TestData>("3.0.0", new TestData(), 1865, 1973));
+        if(JAVA_VERSION >= 8) TEST_DATAS.add(new TestDataDescription<TestDataJava8>("3.1.0", new TestDataJava8(), 2025, 2177));
     };
 
     @Override

test/com/esotericsoftware/kryo/SerializationCompatTestData.java

@@ -26,6 +26,8 @@
 import java.io.Serializable;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.nio.charset.Charset;
 import java.time.*;
 import java.util.*;
@@ -114,6 +116,7 @@ public static class TestData implements Serializable {
 		private Calendar _calendar;
 		private Locale _locale;
 		List<Charset> _charsets;
+		private URL _url;
 
 		private Gender _enum;
 		private EnumSet<Gender> _enumSet;
@@ -188,6 +191,11 @@ public TestData () {
 			_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")));
+			try {
+				_url = new java.net.URL("https://github.com/EsotericSoftware/kryo");
+			} catch (MalformedURLException e) {
+				throw new RuntimeException(e);
+			}
 
 			_enum = Gender.FEMALE;
 			_enumSet = EnumSet.allOf(Gender.class);