如果看到過我前些天寫過的《輕鬆把玩HttpClient之模擬post請求示例》這篇文章，你再看本文就是小菜一碟了，如果你順便懂一些NIO，基本上是毫無壓力了。因為HttpAsyncClient相對於HttpClient，就多了一個NIO，這也是為什麼支援非同步的原因。

       不過我有一個疑問，雖說NIO是同步非阻塞IO，但是HttpAsyncClient提供了回撥的機制，這點兒跟netty很像，所以可以模擬類似於AIO的效果。但是官網上的例子卻基本上都是使用Future<HttpResponse> future = httpclient.execute(request, null);來同步獲得執行結果。

       好吧，反正我是用回撥的方式實現的。程式碼基本上跟httpClient那篇一致。不一樣的地方主要有這麼2個地方：配置ssl時不一樣；呼叫execute方式時，使用回撥。具體程式碼如下：

package com.tgb.ccl.http.simpledemo;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.impl.conn.DefaultProxyRoutePlanner;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import org.apache.http.impl.nio.conn.PoolingNHttpClientConnectionManager;
import org.apache.http.impl.nio.reactor.DefaultConnectingIOReactor;
import org.apache.http.impl.nio.reactor.IOReactorConfig;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.nio.conn.NoopIOSessionStrategy;
import org.apache.http.nio.conn.SchemeIOSessionStrategy;
import org.apache.http.nio.conn.ssl.SSLIOSessionStrategy;
import org.apache.http.nio.reactor.ConnectingIOReactor;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.EntityUtils;

/** 
 * HttpAsyncClient模擬post請求簡單示例
 * 
 * @author arron
 * @date 2015年11月1日 下午2:23:18 
 * @version 1.0 
 */
public class SimpleHttpAsyncClientDemo {
	
	/**
	 * 設定信任自定義的證書
	 * 	
	 * @param keyStorePath		金鑰庫路徑
	 * @param keyStorepass		金鑰庫密碼
	 * @return
	 */
	public static SSLContext custom(String keyStorePath, String keyStorepass) {
		SSLContext sc = null;
		FileInputStream instream = null;
		KeyStore trustStore = null;
		try {
			trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
			instream = new FileInputStream(new File(keyStorePath));
			trustStore.load(instream, keyStorepass.toCharArray());
			// 相信自己的CA和所有自簽名的證書
			sc = SSLContexts.custom().loadTrustMaterial(trustStore, new TrustSelfSignedStrategy()).build();
		} catch (KeyStoreException | NoSuchAlgorithmException| CertificateException | IOException | KeyManagementException e) {
			e.printStackTrace();
		} finally {
			try {
				instream.close();
			} catch (IOException e) {
			}
		}
		return sc;
	}
	
	/**
	 * 繞過驗證
	 * 	
	 * @return
	 * @throws NoSuchAlgorithmException 
	 * @throws KeyManagementException 
	 */
	public static SSLContext createIgnoreVerifySSL() throws NoSuchAlgorithmException, KeyManagementException {
		SSLContext sc = SSLContext.getInstance("SSLv3");

		// 實現一個X509TrustManager介面，用於繞過驗證，不用修改裡面的方法
		X509TrustManager trustManager = new X509TrustManager() {
			@Override
			public void checkClientTrusted(
					java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
					String paramString) throws CertificateException {
			}

			@Override
			public void checkServerTrusted(
					java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
					String paramString) throws CertificateException {
			}

			@Override
			public java.security.cert.X509Certificate[] getAcceptedIssuers() {
				return null;
			}
		};
		sc.init(null, new TrustManager[] { trustManager }, null);
		return sc;
	}

	/**
	 * 設定代理
	 * @param builder
	 * @param hostOrIP
	 * @param port
	 */
	public static HttpAsyncClientBuilder proxy(String hostOrIP, int port){
		// 依次是代理地址，代理埠號，協議型別  
		HttpHost proxy = new HttpHost(hostOrIP, port, "http");  
		DefaultProxyRoutePlanner routePlanner = new DefaultProxyRoutePlanner(proxy);
		return HttpAsyncClients.custom().setRoutePlanner(routePlanner);
	}
	
	/**
	 * 模擬請求
	 * 
	 * @param url				資源地址
	 * @param map			引數列表
	 * @param encoding	編碼
	 * @param handler		結果處理類
	 * @return
	 * @throws NoSuchAlgorithmException 
	 * @throws KeyManagementException 
	 * @throws IOException 
	 * @throws ClientProtocolException 
	 */
	public static void send(String url, Map<String,String> map,final String encoding, final AsyncHandler handler) throws KeyManagementException, NoSuchAlgorithmException, ClientProtocolException, IOException {

		//繞過證書驗證，處理https請求
		SSLContext sslcontext = createIgnoreVerifySSL();
		
        // 設定協議http和https對應的處理socket連結工廠的物件
		Registry<SchemeIOSessionStrategy> sessionStrategyRegistry = RegistryBuilder.<SchemeIOSessionStrategy>create()
                .register("http", NoopIOSessionStrategy.INSTANCE)
                .register("https", new SSLIOSessionStrategy(sslcontext))
                .build();
		//配置io執行緒
        IOReactorConfig ioReactorConfig = IOReactorConfig.custom().setIoThreadCount(Runtime.getRuntime().availableProcessors()).build();
		//設定連線池大小
        ConnectingIOReactor ioReactor;
		ioReactor = new DefaultConnectingIOReactor(ioReactorConfig);
        PoolingNHttpClientConnectionManager connManager = new PoolingNHttpClientConnectionManager(ioReactor, null, sessionStrategyRegistry, null);
        
        //建立自定義的httpclient物件
		final CloseableHttpAsyncClient client = proxy("127.0.0.1", 8087).setConnectionManager(connManager).build();
//		CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
		
		//建立post方式請求物件
		HttpPost httpPost = new HttpPost(url);
		
		//裝填引數
		List<NameValuePair> nvps = new ArrayList<NameValuePair>();
		if(map!=null){
			for (Entry<String, String> entry : map.entrySet()) {
				nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
			}
		}
		//設定引數到請求物件中
		httpPost.setEntity(new UrlEncodedFormEntity(nvps, encoding));

		System.out.println("請求地址："+url);
		System.out.println("請求引數："+nvps.toString());
		
		//設定header資訊
		//指定報文頭【Content-type】、【User-Agent】
		httpPost.setHeader("Content-type", "application/x-www-form-urlencoded");
		httpPost.setHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
		
		// Start the client
		client.start();
		//執行請求操作，並拿到結果（非同步）
		client.execute(httpPost, new FutureCallback<HttpResponse>() {
			
			@Override
			public void failed(Exception ex) {
				handler.failed(ex);
				close(client);
			}
			
			@Override
			public void completed(HttpResponse resp) {
				String body="";
				//這裡使用EntityUtils.toString()方式時會大概率報錯，原因：未接受完畢，連結已關
				try {
					HttpEntity entity = resp.getEntity();
					if (entity != null) {
						final InputStream instream = entity.getContent();
						try {
							final StringBuilder sb = new StringBuilder();
							final char[] tmp = new char[1024];
							final Reader reader = new InputStreamReader(instream,encoding);
							int l;
							while ((l = reader.read(tmp)) != -1) {
								sb.append(tmp, 0, l);
							}
							body = sb.toString();
						} finally {
							instream.close();
							EntityUtils.consume(entity);
						}
					}
				} catch (ParseException | IOException e) {
					e.printStackTrace();
				}
				handler.completed(body);
				close(client);
			}
			
			@Override
			public void cancelled() {
				handler.cancelled();
				close(client);
			}
		});
	}
	
	/**
	 * 關閉client物件
	 * 
	 * @param client
	 */
	private static void close(CloseableHttpAsyncClient client) {
		try {
			client.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	static class AsyncHandler implements IHandler{
		
		@Override
		public Object failed(Exception e) {
			System.err.println(Thread.currentThread().getName()+"--失敗了--"+e.getClass().getName()+"--"+e.getMessage());
			return null;
		}
		@Override
		public Object completed(String respBody) {
			System.out.println(Thread.currentThread().getName()+"--獲取內容："+respBody);
			return null;
		}
		@Override
		public Object cancelled() {
			System.out.println(Thread.currentThread().getName()+"--取消了");
			return null;
		}
	}
	
	/**
	 * 回撥處理介面
	 * 
	 * @author arron
	 * @date 2015年11月10日 上午10:05:40 
	 * @version 1.0
	 */
	public interface IHandler {
		
		/**
		 * 處理異常時，執行該方法
		 * @return
		 */
		Object failed(Exception e);
		
		/**
		 * 處理正常時，執行該方法
		 * @return
		 */
		Object completed(String respBody);
		
		/**
		 * 處理取消時，執行該方法
		 * @return
		 */
		Object cancelled();
	}
	
}
 

	public static void main(String[] args) throws KeyManagementException, NoSuchAlgorithmException, ClientProtocolException, IOException {
		AsyncHandler handler = new AsyncHandler();
		String url = "http://php.weather.sina.com.cn/iframe/index/w_cl.php";
		Map<String, String> map = new HashMap<String, String>();
		map.put("code", "js");
		map.put("day", "0");
		map.put("city", "上海");
		map.put("dfc", "1");
		map.put("charset", "utf-8");
		send(url, map, "utf-8", handler);
		
		System.out.println("-----------------------------------");
		
		map.put("city", "北京");
		send(url, map, "utf-8", handler);
		
		System.out.println("-----------------------------------");
		
	}
 

       很簡單吧，其實基於HttpAsyncClient的工具類我也進行了封裝，跟HttpClient工具類差不多。

       httpclientUtil （QQ交流群:548452686 ）