高并发场景下HTTP请求连接池

package com.comtop.dop.bdap.appservice;


import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TimerTask;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.NameValuePair;
import org.apache.http.NoHttpResponseException;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.protocol.HTTP;
import org.apache.http.protocol.HttpContext;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.comtop.cip.json.JSON;
import com.comtop.cip.json.JSONObject;
import com.comtop.dop.api.engine.dag.DagController;
import com.google.gson.Gson;
import com.google.gson.JsonObject;

import comtop.soa.org.apache.cxf.helpers.IOUtils;

public class HttpConnectionPoolUtil {
    /** 
     * 日志对象 
     */
    
    
    private static Logger logger = LoggerFactory.getLogger(HttpConnectionPoolUtil.class);

    private static final int CONNECT_TIMEOUT = 3000;// 设置连接建立的超时时间为30s
    private static final int SOCKET_TIMEOUT = 5000;
    private static final int MAX_CONN = 100; // 最大连接数
    private static final int Max_PRE_ROUTE = 60; // 路由最大连接数
    private static final int MAX_ROUTE =60;
    private static CloseableHttpClient httpClient; // 发送请求的客户端单例
    private static PoolingHttpClientConnectionManager manager; //连接池管理类
    private static ScheduledExecutorService monitorExecutor;

    private final static Object syncLock = new Object(); // 相当于线程锁,用于线程安全

    /**
     * 对http请求进行基本设置
     * @param httpRequestBase http请求
     */
    private static void setRequestConfig(HttpRequestBase httpRequestBase){
        RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(CONNECT_TIMEOUT)
                .setConnectTimeout(CONNECT_TIMEOUT)
                .setSocketTimeout(SOCKET_TIMEOUT).build();

        httpRequestBase.setConfig(requestConfig);
    }

    public static CloseableHttpClient getHttpClient(String url){
        long startTime=System.currentTimeMillis();
        if (httpClient == null){
            //多线程下多个线程同时调用getHttpClient容易导致重复创建httpClient对象的问题,所以加上了同步锁
            synchronized (syncLock){
                if (httpClient == null){
                    String hostName = url.split("/")[2];
                    int port = 80;
                    if (hostName.contains(":")){
                        String[] args = hostName.split(":");
                        hostName = args[0];
                        port = Integer.parseInt(args[1]);
                    }
                    httpClient = createHttpClient(hostName, port);
                    //开启监控线程,对异常和空闲线程进行关闭
                    monitorExecutor = Executors.newScheduledThreadPool(1);
                    monitorExecutor.scheduleAtFixedRate(new TimerTask() {
                        @Override
                        public void run() {
                            //关闭异常连接
                            manager.closeExpiredConnections();
                            //关闭1s空闲的连接
                            manager.closeIdleConnections(1000, TimeUnit.MILLISECONDS);
                            //logger.info("close expired and idle for over 1s connection");
                        }
                    }, 20, 20, TimeUnit.MILLISECONDS); 
                }
            }
        }       
        return httpClient;
    }

    /**
     * 根据host和port构建httpclient实例
     * @param host 要访问的域名
     * @param port 要访问的端口
     * @return
     */
    public static CloseableHttpClient createHttpClient(String host, int port){
        ConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
        LayeredConnectionSocketFactory sslSocketFactory = SSLConnectionSocketFactory.getSocketFactory();
        Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory> create().register("http", plainSocketFactory)
                .register("https", sslSocketFactory).build();

        manager = new PoolingHttpClientConnectionManager(registry);
        //设置连接参数
        manager.setMaxTotal(MAX_CONN); // 最大连接数
        manager.setDefaultMaxPerRoute(Max_PRE_ROUTE); // 路由最大连接数

        HttpHost httpHost = new HttpHost(host, port);
        manager.setMaxPerRoute(new HttpRoute(httpHost), MAX_ROUTE);

        //请求失败时,进行请求重试
        HttpRequestRetryHandler handler = new HttpRequestRetryHandler() {
            @Override
            public boolean retryRequest(IOException e, int i, HttpContext httpContext) {
                if (i > 3){
                    //重试超过3次,放弃请求
                    logger.error("重试超过3次,放弃请求");
                    return false;
                }
                if (e instanceof NoHttpResponseException){
                    //服务器没有响应,可能是服务器断开了连接,应该重试
                    logger.error("服务器没有响应,可能是服务器断开了连接,请重试");
                    return true;
                }
                if (e instanceof SSLHandshakeException){
                    // SSL握手异常
                    logger.error("SSL握手异常");
                    return false;
                }
                if (e instanceof InterruptedIOException){
                    //超时
                    logger.error("InterruptedIOException");
                    return false;
                }
                if (e instanceof UnknownHostException){
                    // 服务器不可达
                    logger.error("服务器不可达");
                    return false;
                }
                if (e instanceof ConnectTimeoutException){
                    // 连接超时
                    logger.error("连接超时");
                    return false;
                }
                if (e instanceof SSLException){
                    logger.error("SSLException");
                    return false;
                }

                HttpClientContext context = HttpClientContext.adapt(httpContext);
                HttpRequest request = context.getRequest();
                if (!(request instanceof HttpEntityEnclosingRequest)){
                    //如果请求不是关闭连接的请求
                    return true;
                }
                return false;
            }
        };

        CloseableHttpClient client = HttpClients.custom().setConnectionManager(manager).setRetryHandler(handler).build();
        return client;
    }

    /**
     * 设置post请求的参数
     * @param httpPost
     * @param params
     */
    private static void setPostParams(HttpPost httpPost, Map<String, Object> params){
        /*List<NameValuePair> nvps = new ArrayList<NameValuePair>();
        Set<String> keys = params.keySet();
        for (String key: keys){
            nvps.add(new BasicNameValuePair(key, params.get(key).toString()));
        }*/
        StringEntity stringEntity;
        stringEntity = new StringEntity(JSON.toJSONString(params),HTTP.UTF_8);
        httpPost.setEntity(stringEntity);
        //HTTP.DEF_CONTENT_CHARSET
    }

    public static JSONObject post(String url, Map<String, Object> params){
        logger.info("================执行HTTP请求开始====================");
        HttpPost httpPost = new HttpPost(url);
        httpPost.addHeader("Content-Type", "application/json");
        setRequestConfig(httpPost);
        setPostParams(httpPost, params);
        CloseableHttpResponse response = null;
        InputStream in = null;
        JSONObject object = null;
        long startTime=System.currentTimeMillis();
        try {
            response = getHttpClient(url).execute(httpPost, HttpClientContext.create());
            
            long endTime=System.currentTimeMillis();
            
            
            startTime=System.currentTimeMillis();
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                in = entity.getContent();
                String result = IOUtils.toString(in, "utf-8");
                Gson gson = new Gson();
//                object = gson.fromJson(result, JsonObject.class);
                object = JSONObject.parseObject(result);
            }
            
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try{
                if (in != null) in.close();
                if (response != null) response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return object;
    }

    /**
     * 关闭连接池
     */
    public static void closeConnectionPool(){
        try {
            httpClient.close();
            manager.close();
            monitorExecutor.shutdown();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}