Support port URI template variables

This commit makes it possible to specify port with an URI template variable.

For example :
RestTemplate restTemplate = new RestTemplate();
restTemplate.getForObject("http://localhost:{port}/resource", String.class, 8080);

Issue: SPR-12123

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

@@ -52,7 +52,7 @@ final class HierarchicalUriComponents extends UriComponents {
 
 	private final String host;
 
-	private final int port;
+	private final String port;
 
 	private final PathComponent path;
 
@@ -73,7 +73,7 @@ final class HierarchicalUriComponents extends UriComponents {
 	 * @param encoded whether the components are already encoded
 	 * @param verify whether the components need to be checked for illegal characters
 	 */
-	HierarchicalUriComponents(String scheme, String userInfo, String host, int port, PathComponent path,
+	HierarchicalUriComponents(String scheme, String userInfo, String host, String port, PathComponent path,
 			MultiValueMap<String, String> queryParams, String fragment, boolean encoded, boolean verify) {
 
 		super(scheme, fragment);
@@ -109,7 +109,7 @@ final class HierarchicalUriComponents extends UriComponents {
 
 	@Override
 	public int getPort() {
-		return this.port;
+		return Integer.parseInt(this.port);
 	}
 
 	@Override
@@ -308,6 +308,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		String expandedScheme = expandUriComponent(getScheme(), uriVariables);
 		String expandedUserInfo = expandUriComponent(this.userInfo, uriVariables);
 		String expandedHost = expandUriComponent(this.host, uriVariables);
+		String expandedPort = expandUriComponent(this.port, uriVariables);
 		PathComponent expandedPath = this.path.expand(uriVariables);
 		MultiValueMap<String, String> expandedQueryParams =
 				new LinkedMultiValueMap<String, String>(this.queryParams.size());
@@ -321,7 +322,7 @@ final class HierarchicalUriComponents extends UriComponents {
 			expandedQueryParams.put(expandedName, expandedValues);
 		}
 		String expandedFragment = expandUriComponent(this.getFragment(), uriVariables);
-		return new HierarchicalUriComponents(expandedScheme, expandedUserInfo, expandedHost, this.port, expandedPath,
+		return new HierarchicalUriComponents(expandedScheme, expandedUserInfo, expandedHost, expandedPort, expandedPath,
 				expandedQueryParams, expandedFragment, false, false);
 	}
 
@@ -359,7 +360,7 @@ final class HierarchicalUriComponents extends UriComponents {
 			if (this.host != null) {
 				uriBuilder.append(host);
 			}
-			if (this.port != -1) {
+			if (!"-1".equals(this.port)) {
 				uriBuilder.append(':');
 				uriBuilder.append(port);
 			}
@@ -432,7 +433,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		int result = ObjectUtils.nullSafeHashCode(getScheme());
 		result = 31 * result + ObjectUtils.nullSafeHashCode(this.userInfo);
 		result = 31 * result + ObjectUtils.nullSafeHashCode(this.host);
-		result = 31 * result + this.port;
+		result = 31 * result + ObjectUtils.nullSafeHashCode(this.port);
 		result = 31 * result + this.path.hashCode();
 		result = 31 * result + this.queryParams.hashCode();
 		result = 31 * result + ObjectUtils.nullSafeHashCode(getFragment());

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

@@ -70,7 +70,7 @@ public class UriComponentsBuilder {
 
 	private static final String HOST_PATTERN = "(" + HOST_IPV6_PATTERN + "|" + HOST_IPV4_PATTERN + ")";
 
-	private static final String PORT_PATTERN = "(\\d*)";
+	private static final String PORT_PATTERN = "(\\d*(?:\\{[^/]+?\\})?)";
 
 	private static final String PATH_PATTERN = "([^?#]*)";
 
@@ -96,7 +96,7 @@ public class UriComponentsBuilder {
 
 	private String host;
 
-	private int port = -1;
+	private String port = "-1";
 
 	private CompositePathComponentBuilder pathBuilder = new CompositePathComponentBuilder();
 
@@ -192,7 +192,7 @@ public class UriComponentsBuilder {
 				builder.userInfo(userInfo);
 				builder.host(host);
 				if (StringUtils.hasLength(port)) {
-					builder.port(Integer.parseInt(port));
+					builder.port(port);
 				}
 				builder.path(path);
 				builder.query(query);
@@ -237,7 +237,7 @@ public class UriComponentsBuilder {
 			builder.host(host);
 			String port = m.group(7);
 			if (StringUtils.hasLength(port)) {
-				builder.port(Integer.parseInt(port));
+				builder.port(port);
 			}
 			builder.path(m.group(8));
 			builder.query(m.group(10));
@@ -272,7 +272,7 @@ public class UriComponentsBuilder {
 			return new OpaqueUriComponents(this.scheme, this.ssp, this.fragment);
 		}
 		else {
-			return new HierarchicalUriComponents(this.scheme, this.userInfo, this.host, this.port,
+			return new HierarchicalUriComponents(this.scheme, this.userInfo, this.host, String.valueOf(this.port),
 					this.pathBuilder.build(), this.queryParams, this.fragment, encoded, true);
 		}
 	}
@@ -333,7 +333,7 @@ public class UriComponentsBuilder {
 				this.host = uri.getHost();
 			}
 			if (uri.getPort() != -1) {
-				this.port = uri.getPort();
+				this.port = String.valueOf(uri.getPort());
 			}
 			if (StringUtils.hasLength(uri.getRawPath())) {
 				this.pathBuilder = new CompositePathComponentBuilder(uri.getRawPath());
@@ -353,7 +353,7 @@ public class UriComponentsBuilder {
 	private void resetHierarchicalComponents() {
 		this.userInfo = null;
 		this.host = null;
-		this.port = -1;
+		this.port = "-1";
 		this.pathBuilder = new CompositePathComponentBuilder();
 		this.queryParams.clear();
 	}
@@ -393,7 +393,7 @@ public class UriComponentsBuilder {
 				this.host = uriComponents.getHost();
 			}
 			if (uriComponents.getPort() != -1) {
-				this.port = uriComponents.getPort();
+				this.port = String.valueOf(uriComponents.getPort());
 			}
 			if (StringUtils.hasLength(uriComponents.getPath())) {
 				List<String> segments = uriComponents.getPathSegments();
@@ -462,6 +462,18 @@ public class UriComponentsBuilder {
 	 */
 	public UriComponentsBuilder port(int port) {
 		Assert.isTrue(port >= -1, "'port' must not be < -1");
+		this.port = String.valueOf(port);
+		resetSchemeSpecificPart();
+		return this;
+	}
+
+	/**
+	 * Set the URI port. Passing {@code "-1"} will clear the port of this builder.
+	 * The given port may contain URI template variables.
+	 * @param port the URI port
+	 * @return this UriComponentsBuilder
+	 */
+	public UriComponentsBuilder port(String port) {
 		this.port = port;
 		resetSchemeSpecificPart();
 		return this;

spring-web/src/test/java/org/springframework/web/client/AbstractJettyServerTestCase.java

@@ -54,6 +54,7 @@ public class AbstractJettyServerTestCase {
 
 	protected static String helloWorld = "H\u00e9llo W\u00f6rld";
 
+	protected static int port;
 	protected static String baseUrl;
 
 	protected static MediaType textContentType;
@@ -63,7 +64,7 @@ public class AbstractJettyServerTestCase {
 
 	@BeforeClass
 	public static void startJettyServer() throws Exception {
-		int port = SocketUtils.findAvailableTcpPort();
+		port = SocketUtils.findAvailableTcpPort();
 		jettyServer = new Server(port);
 		baseUrl = "http://localhost:" + port;
 		ServletContextHandler handler = new ServletContextHandler();

spring-web/src/test/java/org/springframework/web/client/RestTemplateIntegrationTests.java

@@ -229,6 +229,14 @@ public class RestTemplateIntegrationTests extends AbstractJettyServerTestCase {
 		assertTrue(s.contains("\"without\":\"without\""));
 	}
 
+	// SPR-12123
+
+	@Test
+	public void serverPort() {
+		String s = template.getForObject("http://localhost:{port}/get", String.class, port);
+		assertEquals("Invalid content", helloWorld, s);
+	}
+
 	public interface MyJacksonView1 {};
 	public interface MyJacksonView2 {};
 

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

@@ -80,6 +80,28 @@ public class UriComponentsTests {
 		assertEquals("http://example.com/1 2 3 4", uriComponents.toUriString());
 	}
 
+	// SPR-12123
+
+	@Test
+	public void port() {
+		UriComponents uriComponents1 = UriComponentsBuilder.fromUriString(
+				"http://example.com:8080/bar").build();
+		UriComponents uriComponents2 = UriComponentsBuilder.fromUriString(
+				"http://example.com/bar").port(8080).build();
+		UriComponents uriComponents3 = UriComponentsBuilder.fromUriString(
+				"http://example.com/bar").port("{port}").build().expand(8080);
+		UriComponents uriComponents4 = UriComponentsBuilder.fromUriString(
+				"http://example.com/bar").port("808{digit}").build().expand(0);
+		assertEquals(8080, uriComponents1.getPort());
+		assertEquals("http://example.com:8080/bar", uriComponents1.toUriString());
+		assertEquals(8080, uriComponents2.getPort());
+		assertEquals("http://example.com:8080/bar", uriComponents2.toUriString());
+		assertEquals(8080, uriComponents3.getPort());
+		assertEquals("http://example.com:8080/bar", uriComponents3.toUriString());
+		assertEquals(8080, uriComponents4.getPort());
+		assertEquals("http://example.com:8080/bar", uriComponents4.toUriString());
+	}
+
 	@Test(expected = IllegalStateException.class)
 	public void expandEncoded() {
 		UriComponentsBuilder.fromPath("/{foo}").build().encode().expand("bar");