SPR-8823 Add ServletUriComponentsBuilder.

build-spring-framework/resources/changelog.txt

@@ -22,6 +22,7 @@ Changes in version 3.1 RC2 (2011-11-15)
 * The Form hidden tag supports "disabled" attribute
 * Add ignoreDefaultModelOnRedirect attribute to <mvc:annotation-driven/>
 * Add methods to UriComponentsBuilder for replacing the path or the query.
+* Add ServletUriComponentsBuilder to build a UriComponents instance starting with a ServletRequest
 
 Changes in version 3.1 RC1 (2011-10-11)
 ---------------------------------------

org.springframework.web/src/main/java/org/springframework/web/util/ServletUriComponentsBuilder.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright 2002-2011 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.util;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+import org.springframework.web.context.request.RequestAttributes;
+import org.springframework.web.context.request.RequestContextHolder;
+import org.springframework.web.context.request.ServletRequestAttributes;
+
+/**
+ * A builder for {@link UriComponents} that offers static factory methods to 
+ * extract information from an {@code HttpServletRequest}. 
+ *
+ * @author Rossen Stoyanchev
+ * @since 3.1
+ */
+public class ServletUriComponentsBuilder extends UriComponentsBuilder {
+
+	/**
+	 * Default constructor. Protected to prevent direct instantiation.
+	 *
+	 * @see #fromContextPath(HttpServletRequest)
+	 * @see #fromServletMapping(HttpServletRequest)
+	 * @see #fromRequest(HttpServletRequest)
+	 * @see #fromCurrentContextPath()
+	 * @see #fromCurrentServletMapping()
+ 	 * @see #fromCurrentRequest()
+	 */
+	protected ServletUriComponentsBuilder() {
+	}
+
+	/**
+	 * Return a builder initialized with the host, port, scheme, and the 
+	 * context path of the given request.
+	 */
+	public static ServletUriComponentsBuilder fromContextPath(HttpServletRequest request) {
+		ServletUriComponentsBuilder builder = fromRequest(request);
+		builder.replacePath(new UrlPathHelper().getContextPath(request));
+		builder.replaceQuery(null);
+		return builder;
+	}
+
+	/**
+	 * Return a builder initialized with the host, port, scheme, context path, 
+	 * and the servlet mapping of the given request.
+	 * 
+	 * <p>For example if the servlet is mapped by name, i.e. {@code "/main/*"}, 
+	 * then the resulting path will be {@code /appContext/main}. If the servlet
+	 * path is not mapped by name, i.e. {@code "/"} or {@code "*.html"}, then 
+	 * the resulting path will contain the context path only.
+	 */
+	public static ServletUriComponentsBuilder fromServletMapping(HttpServletRequest request) {
+		ServletUriComponentsBuilder builder = fromContextPath(request);
+		if (StringUtils.hasText(new UrlPathHelper().getPathWithinServletMapping(request))) {
+			builder.path(request.getServletPath());
+		}
+		return builder;
+	}
+
+	/**
+	 * Return a builder initialized with all available information in the given
+	 * request including scheme, host, port, path, and query string.
+	 */
+	public static ServletUriComponentsBuilder fromRequest(HttpServletRequest request) {
+		String scheme = request.getScheme();
+		int port = request.getServerPort();
+
+		ServletUriComponentsBuilder builder = new ServletUriComponentsBuilder();
+		builder.scheme(scheme);
+		builder.host(request.getServerName());
+		if ((scheme.equals("http") && port != 80) || (scheme.equals("https") && port != 443)) {
+			builder.port(port);
+		}
+		builder.path(new UrlPathHelper().getRequestUri(request));
+		builder.query(request.getQueryString());
+		return builder;
+	}
+	
+	/**
+	 * Equivalent to {@link #fromContextPath(HttpServletRequest)} except the
+	 * request is obtained via {@link RequestContextHolder}.
+	 */
+	public static ServletUriComponentsBuilder fromCurrentContextPath() {
+		return fromContextPath(getCurrentRequest());
+	}
+
+	/**
+	 * Equivalent to {@link #fromServletMapping(HttpServletRequest)} except the
+	 * request is obtained via {@link RequestContextHolder}.
+	 */
+	public static ServletUriComponentsBuilder fromCurrentServletMapping() {
+		return fromServletMapping(getCurrentRequest());
+	}
+
+	/**
+	 * Equivalent to {@link #fromRequest(HttpServletRequest)} except the
+	 * request is obtained via {@link RequestContextHolder}.
+	 */
+	public static ServletUriComponentsBuilder fromCurrentRequest() {
+		return fromRequest(getCurrentRequest());
+	}
+
+	private static HttpServletRequest getCurrentRequest() {
+		RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
+		Assert.state(requestAttributes != null, "Could not find current request via RequestContextHolder");
+		Assert.isInstanceOf(ServletRequestAttributes.class, requestAttributes);
+		HttpServletRequest servletRequest = ((ServletRequestAttributes) requestAttributes).getRequest();
+		Assert.state(servletRequest != null, "Could not find current HttpServletRequest");
+		return servletRequest;
+	}
+	
+}

org.springframework.web/src/test/java/org/springframework/web/util/ServletUriComponentsBuilderTests.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2002-2011 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.util;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.web.context.request.RequestContextHolder;
+import org.springframework.web.context.request.ServletRequestAttributes;
+
+/**
+ * @author Rossen Stoyanchev
+ */
+public class ServletUriComponentsBuilderTests {
+
+	private MockHttpServletRequest request;
+
+	@Before
+	public void setup() {
+		this.request = new MockHttpServletRequest();
+		this.request.setScheme("http");
+		this.request.setServerName("localhost");
+		this.request.setServerPort(80);
+		this.request.setContextPath("/mvc-showcase");
+	}
+	
+	@Test
+	public void fromRequest() {
+		request.setRequestURI("/mvc-showcase/data/param");
+		request.setQueryString("foo=123");
+
+		String result = ServletUriComponentsBuilder.fromRequest(request).build().toUriString();
+
+		assertEquals("http://localhost/mvc-showcase/data/param?foo=123", result);
+	}
+
+	@Test
+	public void fromRequestEncodedPath() {
+		request.setRequestURI("/mvc-showcase/data/foo%20bar;jsessionid=123");
+
+		String result = ServletUriComponentsBuilder.fromRequest(request).build().toUriString();
+
+		assertEquals("http://localhost/mvc-showcase/data/foo bar", result);
+	}
+
+	@Test
+	public void fromRequestAtypicalHttpPort() {
+		request.setServerPort(8080);
+		String result = ServletUriComponentsBuilder.fromRequest(request).build().toUriString();
+		
+		assertEquals("http://localhost:8080", result);
+	}
+	
+	@Test
+	public void fromRequestAtypicalHttpsPort() {
+		request.setScheme("https");
+		request.setServerPort(9043);
+		
+		String result = ServletUriComponentsBuilder.fromRequest(request).build().toUriString();
+		
+		assertEquals("https://localhost:9043", result);
+	}
+
+	@Test
+	public void fromContextPath() {
+		request.setRequestURI("/mvc-showcase/data/param");
+		request.setQueryString("foo=123");
+		
+		String result = ServletUriComponentsBuilder.fromContextPath(request).build().toUriString();
+		
+		assertEquals("http://localhost/mvc-showcase", result);
+	}	
+
+	@Test
+	public void fromServletMapping() {
+		request.setRequestURI("/mvc-showcase/app/simple");
+		request.setServletPath("/app");
+		request.setQueryString("foo=123");
+		
+		String result = ServletUriComponentsBuilder.fromServletMapping(request).build().toUriString();
+		
+		assertEquals("http://localhost/mvc-showcase/app", result);
+	}	
+
+	@Test
+	public void fromCurrentRequest() {
+		request.setRequestURI("/mvc-showcase/data/param");
+		request.setQueryString("foo=123");
+		RequestContextHolder.setRequestAttributes(new ServletRequestAttributes(this.request));
+
+		try {
+			String result = ServletUriComponentsBuilder.fromCurrentRequest().build().toUriString();
+
+			assertEquals("http://localhost/mvc-showcase/data/param?foo=123", result);
+		}
+		finally {
+			RequestContextHolder.resetRequestAttributes();
+		}
+	}
+	
+}