HttpClient4.5 使用http连接池发送http请求深度示例

HttpClient 3.x,4.x都提供http连接池管理器,当使用了请求连接池管理器（比如PoolingHttpClientConnectionManager）后，HttpClient就可以同时执行多个线程的请求了。

hc3.x和4.x的早期版本,提供了PoolingClientConnectionManager,DefaultHttpClient等类来实现http连接池,但这些类在4.3.x版本之后大部分就已经过时,本文使用4.3.x提供的最新的PoolingHttpClientConnectionManager等类进行http连接池的实现.
废话不多说,下面是全部代码:

public class PoolTest {
	private static void config(HttpRequestBase httpRequestBase) {
		httpRequestBase.setHeader("User-Agent", "Mozilla/5.0");
		httpRequestBase.setHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
		httpRequestBase.setHeader("Accept-Language", "zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3");//"en-US,en;q=0.5");
		httpRequestBase.setHeader("Accept-Charset", "ISO-8859-1,utf-8,gbk,gb2312;q=0.7,*;q=0.7");
		
	    // 配置请求的超时设置
		RequestConfig requestConfig = RequestConfig.custom()
				.setConnectionRequestTimeout(3000)
				.setConnectTimeout(3000)
				.setSocketTimeout(3000)
				.build();
		httpRequestBase.setConfig(requestConfig);		
	}

	public static void main(String[] args) {
    	ConnectionSocketFactory plainsf = PlainConnectionSocketFactory.getSocketFactory();
        LayeredConnectionSocketFactory sslsf = SSLConnectionSocketFactory.getSocketFactory();
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", plainsf)
                .register("https", sslsf)
                .build();

		PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(registry);
		// 将最大连接数增加到200
		cm.setMaxTotal(200);
		// 将每个路由基础的连接增加到20
		cm.setDefaultMaxPerRoute(20);

		// 将目标主机的最大连接数增加到50
		HttpHost localhost = new HttpHost("http://blog.csdn.net/gaolu",80);
		cm.setMaxPerRoute(new HttpRoute(localhost), 50);
		
		//请求重试处理
		HttpRequestRetryHandler httpRequestRetryHandler = new HttpRequestRetryHandler() {
	        public boolean retryRequest(IOException exception,int executionCount, HttpContext context) {
	            if (executionCount >= 5) {// 如果已经重试了5次，就放弃	                
	                return false;
	            }
				if (exception instanceof NoHttpResponseException) {// 如果服务器丢掉了连接，那么就重试					
					return true;
				}
				if (exception instanceof SSLHandshakeException) {// 不要重试SSL握手异常					
					return false;
				}	            
	            if (exception instanceof InterruptedIOException) {// 超时	                
	                return false;
	            }
	            if (exception instanceof UnknownHostException) {// 目标服务器不可达	                
	                return false;
	            }
	            if (exception instanceof ConnectTimeoutException) {// 连接被拒绝	                
	                return false;
	            }
	            if (exception instanceof SSLException) {// ssl握手异常	                
	                return false;
	            }
	            
	            HttpClientContext clientContext = HttpClientContext.adapt(context);
	            HttpRequest request = clientContext.getRequest();
	            // 如果请求是幂等的，就再次尝试
	            if (!(request instanceof HttpEntityEnclosingRequest)) {	                
	                return true;
	            }
	            return false;
	        }
	    };  
	    
		CloseableHttpClient httpClient = HttpClients.custom()
				.setConnectionManager(cm)
				.setRetryHandler(httpRequestRetryHandler)
				.build();

		// URL列表数组
		String[] urisToGet = { 		
				"http://blog.csdn.net/gaolu/article/details/48466059",
				"http://blog.csdn.net/gaolu/article/details/48243103",
				"http://blog.csdn.net/gaolu/article/details/47656987",
				"http://blog.csdn.net/gaolu/article/details/47055029",
				
				"http://blog.csdn.net/gaolu/article/details/46400883",
				"http://blog.csdn.net/gaolu/article/details/46359127",
				"http://blog.csdn.net/gaolu/article/details/46224821",
				"http://blog.csdn.net/gaolu/article/details/45305769",
				
				"http://blog.csdn.net/gaolu/article/details/43701763",
				"http://blog.csdn.net/gaolu/article/details/43195449",
				"http://blog.csdn.net/gaolu/article/details/42915521",
				"http://blog.csdn.net/gaolu/article/details/41802319",
				
				"http://blog.csdn.net/gaolu/article/details/41045233",
				"http://blog.csdn.net/gaolu/article/details/40395425",
				"http://blog.csdn.net/gaolu/article/details/40047065",
				"http://blog.csdn.net/gaolu/article/details/39891877",
				
				"http://blog.csdn.net/gaolu/article/details/39499073",
				"http://blog.csdn.net/gaolu/article/details/39314327",
				"http://blog.csdn.net/gaolu/article/details/38820809",
				"http://blog.csdn.net/gaolu/article/details/38439375",
		};
		
		long start = System.currentTimeMillis();		
		try {
			int pagecount = urisToGet.length;
			ExecutorService executors = Executors.newFixedThreadPool(pagecount);
			CountDownLatch countDownLatch = new CountDownLatch(pagecount); 		
			for(int i = 0; i< pagecount;i++){
				HttpGet httpget = new HttpGet(urisToGet[i]);
				config(httpget);

				//启动线程抓取
				executors.execute(new GetRunnable(httpClient,httpget,countDownLatch));
			}

			countDownLatch.await();
			executors.shutdown();
		} catch (InterruptedException e) {
			e.printStackTrace();
		} finally {
			System.out.println("线程" + Thread.currentThread().getName() + "," + System.currentTimeMillis() + ", 所有线程已完成，开始进入下一步！");
		}		
		
		long end = System.currentTimeMillis();
		System.out.println("consume -> " + (end - start));
	}
	
	static class GetRunnable implements Runnable {
		private CountDownLatch countDownLatch;
		private final CloseableHttpClient httpClient;
		private final HttpGet httpget;
		
		public GetRunnable(CloseableHttpClient httpClient, HttpGet httpget, CountDownLatch countDownLatch){
			this.httpClient = httpClient;
			this.httpget = httpget;
			
			this.countDownLatch = countDownLatch;
		}

		@Override
		public void run() {
			CloseableHttpResponse response = null;
			try {
				response = httpClient.execute(httpget,HttpClientContext.create());
				HttpEntity entity = response.getEntity();
				System.out.println(EntityUtils.toString(entity, "utf-8")) ;
				EntityUtils.consume(entity);
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				countDownLatch.countDown();
				
				try {
					if(response != null)
						response.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}	
}

主要参考文档:
http://free0007.iteye.com/blog/2012308