演示使用HttpUrlConnection

kaven-G · Mar 28, 2012 · 158c7e3 · 158c7e3
1 parent ffbfa8b
commit 158c7e3
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Showing 2 changed files with 73 additions and 18 deletions.
diff --git a/...les/showcase/src/main/java/org/springside/examples/showcase/web/RemoteContentServlet.java b/...les/showcase/src/main/java/org/springside/examples/showcase/web/RemoteContentServlet.java
@@ -1,8 +1,11 @@
 package org.springside.examples.showcase.web;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
@@ -78,8 +81,38 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response) t
 			response.sendError(HttpServletResponse.SC_BAD_REQUEST, "contentUrl parameter is required.");
 		}
 
-		//远程访问获取内容
-		HttpEntity entity = fetchContent(contentUrl);
+		//远程访问获取内容的方式
+		String client = request.getParameter("client");
+
+		InputStream input = null;
+		if ("apache".equals(client)) {
+			//使用Apache HttpClient
+			fetchContentByApacheHttpClient(response, contentUrl);
+		} else {
+			//使用JDK HttpUrlConnection
+			fetchContentByJDKConnection(response, contentUrl);
+		}
+	}
+
+	/**
+	 * 使用HttpClient取得内容.
+	 */
+	private void fetchContentByApacheHttpClient(HttpServletResponse response, String contentUrl) throws IOException {
+
+		//获取内容
+		HttpEntity entity = null;
+		HttpGet httpGet = new HttpGet(contentUrl);
+		try {
+			HttpContext context = new BasicHttpContext();
+			HttpResponse remoteResponse = httpClient.execute(httpGet, context);
+			entity = remoteResponse.getEntity();
+		} catch (Exception e) {
+			logger.error("fetch remote content" + contentUrl + "  error", e);
+			httpGet.abort();
+			return;
+		}
+
+		//404返回
 		if (entity == null) {
 			response.sendError(HttpServletResponse.SC_NOT_FOUND, contentUrl + " is not found.");
 			return;
@@ -94,7 +127,6 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response) t
 		//输出内容
 		InputStream input = entity.getContent();
 		OutputStream output = response.getOutputStream();
-
 		try {
 			//基于byte数组读取InputStream并直接写入OutputStream, 数组默认大小为4k.
 			IOUtils.copy(input, output);
@@ -103,22 +135,44 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response) t
 			//保证InputStream的关闭.
 			IOUtils.closeQuietly(input);
 		}
+
 	}
 
-	/**
-	 * 使用HttpClient取得内容.
-	 */
-	private HttpEntity fetchContent(String targetUrl) {
-		HttpGet httpGet = new HttpGet(targetUrl);
-		HttpContext context = new BasicHttpContext();
+	private void fetchContentByJDKConnection(HttpServletResponse response, String contentUrl) throws IOException {
+
+		HttpURLConnection connection = (HttpURLConnection) new URL(contentUrl).openConnection();
+		//设置Socket超时
+		connection.setReadTimeout(TIMEOUT_SECONDS * 1000);
 		try {
-			HttpResponse remoteResponse = httpClient.execute(httpGet, context);
-			return remoteResponse.getEntity();
-		} catch (Exception e) {
-			logger.error("fetch remote content" + targetUrl + "  error", e);
-			httpGet.abort();
-			return null;
+			connection.connect();
+
+			//真正发出请求
+			InputStream input;
+			try {
+				input = connection.getInputStream();
+			} catch (FileNotFoundException e) {
+				response.sendError(HttpServletResponse.SC_NOT_FOUND, contentUrl + " is not found.");
+				return;
+			}
+
+			//设置Header
+			response.setContentType(connection.getContentType());
+			if (connection.getContentLength() > 0) {
+				response.setContentLength(connection.getContentLength());
+			}
+
+			//输出内容
+			OutputStream output = response.getOutputStream();
+			try {
+				//基于byte数组读取InputStream并直接写入OutputStream, 数组默认大小为4k.
+				IOUtils.copy(input, output);
+				output.flush();
+			} finally {
+				//保证InputStream的关闭.
+				IOUtils.closeQuietly(input);
+			}
+		} finally {
+			connection.disconnect();
 		}
 	}
-
 }
diff --git a/examples/showcase/src/main/webapp/WEB-INF/views/story/web.jsp b/examples/showcase/src/main/webapp/WEB-INF/views/story/web.jsp
@@ -18,8 +18,9 @@
 		<p>
 			    1. 静态内容Servlet, 演示高效读取静态内容, 控制客户端缓存, 压缩传输, 弹出下载对话框, 见StaticContentServlet.<br/>
 			       <img src="${ctx}/static-content?contentPath=static/img/logo.jpg"/> <a href="${ctx}/static-content?contentPath=img/logo.jpg&download=true">图片下载链接</a><br/>
-			 	2. 远程内容Servlet, 演示使用Apache HttpClient多线程高效获取远程网站内容, 见RemoteContentServlet.<br/>
-			 	   <img src="${ctx}/remote-content?contentUrl=<%=encodedImageUrl%>"/><br/>
+			 	2. 远程内容Servlet, 演示使用两种http client多线程高效获取远程网站内容, 见RemoteContentServlet.<br/>
+			 	   <img src="${ctx}/remote-content?client=apache&contentUrl=<%=encodedImageUrl%>"/> Apache HttpClient.<br/>
+			 	   <img src="${ctx}/remote-content?client=jdk&contentUrl=<%=encodedImageUrl%>"/> JDK HttpUrlConnection.<br/>
 			    3. CacheControlHeaderFilter为静态内容添加缓存控制 Header.<br/>
 			    4. YUI Compressor 压缩js/css,见bin/yuicompressor.bat命令及webapp中两个版本的js/css文件<br/>
 		</p>