HttpClient的连接池

HttpClient因易用性和灵活性优于URLConnection,尤其适合接口测试。本文讨论为何使用Http连接池,如降低延迟、支持更大并发,并提及HttpClient4.3后推荐使用连接池,介绍相关参考资料。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

写在前面

HttpClient相比传统JDK自带的URLConnection,增加了易用性和灵活性,它不仅是客户端发送Http请求变得容易,而且也方便了开发人员测试接口(基于Http协议的),即提高了开发的效率,也方便提高代码的健壮性。

一、为什么要用Http连接池

1、降低延迟:如果不采用连接池,每次连接发起Http请求的时候都会重新建立TCP连接(经历3次握手),用完就会关闭连接(4次挥手)。

2、支持更大的并发:如果不采用连接池,每次连接都会打开一个端口,在大并发的情况下系统的端口资源很快就会被用完,导致无法建立新的连接。

二、具体实现

httpclient4.3之后就推荐使用连接池的方式了。

package com.icekredit.credit.common.utils;

import net.sf.json.JSONObject;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
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.config.Registry;
import org.apache.http.config.RegistryBuilder;
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.apache.http.ssl.SSLContextBuilder;
import org.apache.http.ssl.TrustStrategy;
import org.apache.http.util.EntityUtils;

import javax.net.ssl.SSLContext;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Class 提高并发数,减少握手次数,httpclient的连接池
 *
 * @author hua xu
 * @version 1.0.0
 * @date 16/08/15
 */
public class HttpUtils {
    private static String NULL_URL = "url is null!";
    private static String ERROR_TYPE = "method is not support!";

    // 类初始化时,自动实例化,饿汉单例模式
    private static final HttpUtils httpUtils = new HttpUtils();

    // 创建httpclient连接池
    private PoolingHttpClientConnectionManager httpClientConnectionManager = null;

    // 单例的静态方法,返回HttpUtils的实例
    public static HttpUtils getHttpUtils() {
        return httpUtils;
    }

    // 私有的构造函数
    private HttpUtils() {
        initHttpClient();
    }

    /**
     * 发送请求
     *
     * @param method     请求方法
     * @param urlString  url
     * @param jsonObject json
     * @return
     * @throws URISyntaxException
     */
    public static String httpRequest(String method, String urlString, JSONObject jsonObject) throws
            URISyntaxException, MalformedURLException {
        if (StringUtils.isEmpty(urlString)) {
            return NULL_URL;
        } else {
            urlString = urlString.trim();
            URL url = new URL(urlString);
            URI uri = new URI(url.getProtocol(), url.getHost(), url.getPath(), url.getQuery(), null);

            CloseableHttpClient httpClient = null;
            if (urlString.startsWith("https")) {
                httpClient = getSSLHttpClient();
            } else {
                httpClient = httpUtils.getHttpClient();
            }
            CloseableHttpResponse response = null;
            String json = null;

            switch (method) {
                case "GET": {
                    HttpGet http = new HttpGet(uri);
                    try {
                        response = httpClient.execute(http);
                        HttpEntity entity = response.getEntity();
                        json = EntityUtils.toString(entity, "utf-8");
                        EntityUtils.consume(entity);
                        return json;
                    } catch (UnsupportedOperationException | IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (response != null) {
                            try {
                                response.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                        http.releaseConnection();
                    }
                }
                case "POST": {
                    HttpPost http = new HttpPost(uri);
                    try {
                        StringEntity entity = new StringEntity(jsonObject.toString(), "utf-8");    // 解决中文乱码问题

                        entity.setContentEncoding("UTF-8");
                        entity.setContentType("application/json");
                        http.setEntity(entity);
                        response = httpClient.execute(http);

                        HttpEntity httpEntity = response.getEntity();
                        json = EntityUtils.toString(httpEntity, "utf-8");
                        EntityUtils.consume(entity);
                        return json;
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (response != null) {
                            try {
                                response.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                        http.releaseConnection();
                    }
                }
                default:
                    return ERROR_TYPE;
            }
        }
    }

    /**
     * 发送请求
     *
     * @param urlString url
     * @param params    发送map
     * @return
     * @throws MalformedURLException
     * @throws URISyntaxException
     */
    public static String httpRequest(String urlString, Map<String, Object> params) throws MalformedURLException,
            URISyntaxException {
        if (StringUtils.isEmpty(urlString)) {
            return NULL_URL;
        } else {
            urlString = urlString.trim();
            URL url = new URL(urlString);
            URI uri = new URI(url.getProtocol(), url.getHost(), url.getPath(), url.getQuery(), null);

            CloseableHttpClient httpClient = null;
            if (urlString.startsWith("https")) {
                httpClient = getSSLHttpClient();
            } else {
                httpClient = httpUtils.getHttpClient();
            }
            CloseableHttpResponse response = null;
            String json = null;

            HttpPost http = new HttpPost(uri);

            try {
                setPostParams(http, params);
                response = httpClient.execute(http);
                HttpEntity httpEntity = response.getEntity();
                json = EntityUtils.toString(httpEntity, "utf-8");
                EntityUtils.consume(httpEntity);
                return json;
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (response != null) {
                    try {
                        response.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                http.releaseConnection();
            }
            return json;
        }
    }

    private static void setPostParams(HttpPost httpost, Map<String, Object> params) {
        List<NameValuePair> nvps = new ArrayList<NameValuePair>();
        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) {
            e.printStackTrace();
        }
    }

    /**
     * 创建httpclient连接池,并初始化httpclient
     */
    public void initHttpClient() {
        LayeredConnectionSocketFactory ssl_sf = null;

        try {
            ssl_sf = new SSLConnectionSocketFactory(SSLContext.getDefault());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }

        Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
                .register("https", ssl_sf)
                .register("http",
                        new PlainConnectionSocketFactory())
                .build();

        // 创建httpclient连接池
        httpClientConnectionManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);

        // 设置连接池最大数量
        httpClientConnectionManager.setMaxTotal(200);

        // 设置单个路由最大连接数量
        httpClientConnectionManager.setDefaultMaxPerRoute(20);
    }

    /**
     * 多线程调用时,需要创建自己的httpclient
     *
     * @return
     */
    public CloseableHttpClient getHttpClient() {
        RequestConfig requestConfig = RequestConfig.custom()
                .setConnectTimeout(60000)
                .setSocketTimeout(60000).build();

        CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(httpClientConnectionManager)
                .setDefaultRequestConfig(requestConfig).build();

        /* CloseableHttpClient httpClient = HttpClients.createDefault();//如果不采用连接池就是这种方式获取连接 */
        return httpClient;
    }

    /**
     * 针对https采用SSL的方式创建httpclient
     *
     * @return
     */
    public static CloseableHttpClient getSSLHttpClient() {
        try {
            SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                //信任所有
                public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
                    return true;
                }
            }).build();

            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext);

            return HttpClients.custom().setSSLSocketFactory(sslsf).build();

        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (KeyStoreException e) {
            e.printStackTrace();
        }

        return HttpClients.createDefault();
    }
}


//~ Formatted by Jindent --- http://www.jindent.com

参考链接
HttpClient4.5.2 连接池原理及注意事项
HttpClient使用详解
HttpClient4.3教程 第二章 连接管理
Http请求连接池 - HttpClient 连接池

评论 1
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值