Make HierarchicalUriComponents Serializable

Issue: SPR-10266

spring-web/src/main/java/org/springframework/web/util/HierarchicalUriComponents.java

@@ -17,6 +17,7 @@
 package org.springframework.web.util;
 
 import java.io.ByteArrayOutputStream;
+import java.io.Serializable;
 import java.io.UnsupportedEncodingException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -615,7 +616,7 @@ final class HierarchicalUriComponents extends UriComponents {
 	/**
 	 * Defines the contract for path (segments).
 	 */
-	interface PathComponent {
+	interface PathComponent extends Serializable {
 
 		String getPath();
 

spring-web/src/test/java/org/springframework/web/util/UriComponentsTests.java

@@ -16,11 +16,16 @@
 
 package org.springframework.web.util;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 import java.net.URI;
 import java.net.URISyntaxException;
 
 import org.junit.Test;
 
+import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.*;
 
 /** @author Arjen Poutsma */
@@ -75,4 +80,16 @@ public class UriComponentsTests {
 		assertEquals("http://example.com/bar", uriComponents.normalize().toString());
 	}
 
+	@Test
+	public void serializable() throws Exception {
+		UriComponents uriComponents = UriComponentsBuilder.fromUriString(
+				"http://example.com").path("/{foo}").query("bar={baz}").build();
+		ByteArrayOutputStream bos = new ByteArrayOutputStream();
+		ObjectOutputStream oos = new ObjectOutputStream(bos);
+		oos.writeObject(uriComponents);
+		ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(bos.toByteArray()));
+		UriComponents readObject = (UriComponents) ois.readObject();
+		assertThat(uriComponents.toString(), equalTo(readObject.toString()));
+	}
+
 }