1、场景

有某个业务需要使用https请求内部服务。发现服务器下载宽带占用达到30M/s。大大超出宽带可承受的范围。

2、分析

通过抓包发现TLS的证书占用很大，并且每次tcp都需要申请和获取证书。
http每次请求都需要三次握手和四次挥手，如果是高频请求的话，反复创建和销毁是十分耗时的。https因为还需要申请证书更是耗时。

3、实现

package com.world.util;


import org.apache.http.*;
import org.apache.http.client.HttpRequestRetryHandler;
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.HttpGet;
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.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.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;
import org.slf4j.LoggerFactory;

import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.UnknownHostException;
import java.util.*;

/**
 * HttpClient工具类
 */
public class HttpPoolKit {
    private static final org.slf4j.Logger log = LoggerFactory.getLogger(HttpPoolKit.class);

    private static int timeOut = 10 * 1000;
    private static int connectTimeOut = 10 * 1000;
    private static int socketTimeOut = 10 * 1000;
    private static int maxTotal = 100;
    private static int maxPerRoute = 10;
    private static int maxRoute = 10;

    private static CloseableHttpClient httpClient = null;

    private final static Object syncLock = new Object();


    static {
        InputStream stream = HttpPoolKit.class.getClassLoader().getResourceAsStream("main.properties");
        Properties props = new Properties();
        try {
            props.load(stream);
            timeOut = Integer.valueOf(props.getProperty("timeOut"));
            connectTimeOut = Integer.valueOf(props.getProperty("connectTimeOut"));
            socketTimeOut = Integer.valueOf(props.getProperty("socketTimeOut"));

            maxTotal = Integer.valueOf(props.getProperty("maxTotal"));
            maxPerRoute = Integer.valueOf(props.getProperty("maxPerRoute"));
            maxRoute = Integer.valueOf(props.getProperty("maxRoute"));
        } catch (Exception e) {
            log.error("load properties error", e);
        }
    }

    private static void config(HttpRequestBase httpRequestBase) {
        // 设置Header等
        // 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(timeOut) // 连接请求超时设置
                                                   .setConnectTimeout(connectTimeOut)  // 连接超时设置
                                                   .setSocketTimeout(socketTimeOut)   // socket通信超时设置
                                                   .build();

        httpRequestBase.setConfig(requestConfig);
    }

    /**
     * 获取HttpClient对象
     *
     * @return
     */
    public static CloseableHttpClient getHttpClient(String url) {
        //  https://www.aaa.com/bbb/ccc   http://www.aaa.com/bbb/ccc   aaa.com/bbb/ccc
        String hostname = url.split("/")[2];
        int port = 80;
        if (hostname.contains(":")) {
            String[] arr = hostname.split(":");
            hostname = arr[0];
            port = Integer.parseInt(arr[1]);
        }

        // 双重校验锁
        if (httpClient == null) {
            synchronized (syncLock) {
                if (httpClient == null) {
                    httpClient = createHttpClient(maxTotal, maxPerRoute, maxRoute, hostname, port);
                }
            }
        }
        return httpClient;
    }

    /**
     * 创建HttpClient对象
     *
     * @param maxTotal
     * @param maxPerRoute
     * @param maxRoute
     * @param hostname
     * @param port
     * @return
     */
    public static CloseableHttpClient createHttpClient(int maxTotal,
                                                       int maxPerRoute,
                                                       int maxRoute,
                                                       String hostname,
                                                       int port) {

        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
        cm.setMaxTotal(maxTotal);
        // 将每个路由基础的连接增加
        cm.setDefaultMaxPerRoute(maxPerRoute);
        HttpHost httpHost = new HttpHost(hostname, port);
        // 将目标主机的最大连接数增加
        cm.setMaxPerRoute(new HttpRoute(httpHost), maxRoute);

        // 请求重试处理
        HttpRequestRetryHandler httpRequestRetryHandler = new HttpRequestRetryHandler() {

            @Override
            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();
                // 如果请求不是幂等的，就再次尝试
                if (!(request instanceof HttpEntityEnclosingRequest)) {
                    return true;
                }
                return false;
            }
        };

        CloseableHttpClient httpClient = HttpClients.custom()
                                                    .setConnectionManager(cm)
                                                    .setRetryHandler(httpRequestRetryHandler)
                                                    .build();

        return httpClient;
    }

    /**
     * @param httpost
     * @param params
     */
    private static void setPostParams(HttpPost httpost,
                                      Map<String, Object> params) {
        List<NameValuePair> nvps = new ArrayList<>();
        Set<String> keySet = params.keySet();
        for (String key : keySet) {
            nvps.add(new BasicNameValuePair(key, params.get(key).toString()));
        }
        try {
            httpost.setEntity(new UrlEncodedFormEntity(nvps, "UTF-8"));
        } catch (UnsupportedEncodingException e) {
            log.error("error", e);
        }
    }

    /**
     * POST请求URL获取内容
     *
     * @param url
     * @return
     * @throws IOException
     */
    public static String post(String url, Map<String, Object> params) throws IOException {
        HttpPost httppost = new HttpPost(url);
        config(httppost);
        setPostParams(httppost, params);
        CloseableHttpResponse response = null;
        try {
            response = getHttpClient(url).execute(httppost,
                    HttpClientContext.create());
            HttpEntity entity = response.getEntity();
            String result = EntityUtils.toString(entity, "utf-8");
            EntityUtils.consume(entity);
            return result;
        } catch (Exception e) {
            log.error("error", e);
            throw e;
        } finally {
            try {
                if (response != null)
                    response.close();
            } catch (IOException e) {
                log.error("error", e);
            }
        }
    }

    /**
     * GET请求URL获取内容
     *
     * @param url
     * @return
     */
    public static String get(String url) {
        HttpGet httpget = new HttpGet(url);
        config(httpget);
        CloseableHttpResponse response = null;
        try {
            response = getHttpClient(url).execute(httpget, HttpClientContext.create());

            HttpEntity entity = response.getEntity();
            String result = EntityUtils.toString(entity, "utf-8");
            EntityUtils.consume(entity);
            return result;
        } catch (IOException e) {
            log.error("error", e);
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                log.error("error", e);
            }
        }
        return null;
    }

}

测试代码

package com.eblly.network;

import com.eblly.util.HttpUtil;
import org.junit.Test;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 测试http请求效率
 *
 * @author eblly
 * @since 2018/10/3
 */
public class MultiHttpTs_2 {

    @Test
    public void httpTs() throws InterruptedException {

        request("测试4-1", 1000, 100);
        request("测试4-2", 10000, 100);
//        request("测试4-3", 100000, 100);
        //不使用http连接池
        //测试4-1 ==>耗时: 3697.0毫秒
        //测试4-2 ==>耗时: 30483.0毫秒

        //使用http连接池
        //测试4-1 ==>耗时: 2023.0毫秒
        //测试4-2 ==>耗时: 10909.0毫秒

    }

    /**
     * @param msg
     * @param requestSize
     * @param threadSize
     * @throws InterruptedException
     */
    private void request(String msg, int requestSize, int threadSize) throws InterruptedException {
        CountDownLatch countDownLatch = null;
        AtomicInteger atomicInteger = null;

        countDownLatch = new CountDownLatch(requestSize);
        atomicInteger = new AtomicInteger(requestSize);

        long startTime = System.currentTimeMillis();
        ExecutorService executorService = Executors.newFixedThreadPool(threadSize);
        //使用线程池
        for (int i = 0; i < threadSize; i++) {
            executorService.execute(new DownRunnable(countDownLatch, atomicInteger));
        }
        countDownLatch.await();
        long endTime = System.currentTimeMillis();


        double time = (endTime - startTime);
        System.out.println(msg + " ==>耗时: " + time + "毫秒");
    }


    /**
     * 下载线程
     */
    private class DownRunnable implements Runnable {
        private CountDownLatch countDownLatch;
        private AtomicInteger atomicInteger;
        public static final String host = "https://www.baidu.com";

        public DownRunnable(CountDownLatch countDownLatch, AtomicInteger atomicInteger) {
            super();
            this.countDownLatch = countDownLatch;
            this.atomicInteger = atomicInteger;
        }

        @Override

        public void run() {
            try {
                while (atomicInteger.decrementAndGet() >= 0) {
                    try {
//                        String reposne = HttpUtil.get(host, "");

                        String reposne = HttpClientUtil.get(host);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                    countDownLatch.countDown();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

测试结果

        //不使用http连接池
        //测试4-1 ==>耗时: 3697.0毫秒
        //测试4-2 ==>耗时: 30483.0毫秒

        //使用http连接池
        //测试4-1 ==>耗时: 2023.0毫秒
        //测试4-2 ==>耗时: 10909.0毫秒

3.1、对比

未使用http连接池

未使用http连接池，客户端重复向服务端请求证书。

使用http连接池

使用http连接池，不再重复申请证书。

参考：

• http://www.cnblogs.com/bethunebtj/p/8493379.html
• https://yq.aliyun.com/articles/294