本文共 5937 字，大约阅读时间需要 19 分钟。

依赖

               
    
     org.apache.httpcomponents
                
    
     httpclient
                
    
     4.5.2
            
   

工具类

package com.jerry.utls;package com.httpclinet;import java.io.IOException;import java.util.ArrayList;import java.util.List;import java.util.Map;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.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;/** * http工具类 * @author jerryjin */public class HttpClientUtil {
       private RequestConfig requestConfig = RequestConfig.custom()            .setSocketTimeout(15000)            .setConnectTimeout(15000)            .setConnectionRequestTimeout(15000)            .build();    private volatile static HttpClientUtil instance = null;        private HttpClientUtil(){
   }        public static HttpClientUtil getInstance(){
           if (instance == null) {
               synchronized (HttpClientUtil.class) {
                   if (instance == null) {
                       instance = new HttpClientUtil();                }            }        }        return instance;    }        /**     * 发送 post请求     * @param httpUrl 地址     */    public String sendHttpPost(String httpUrl) {
           HttpPost httpPost = new HttpPost(httpUrl);        return sendHttpPost(httpPost);    }    /**     * 发送 post请求     * @param httpUrl 地址     * @param params 参数(格式:key1=value1&key2=value2)     */    public String sendHttpPost(String httpUrl, String params) {
           HttpPost httpPost = new HttpPost(httpUrl);        try {
               //设置参数            StringEntity stringEntity = new StringEntity(params, "UTF-8");            stringEntity.setContentType("application/x-www-form-urlencoded");            httpPost.setEntity(stringEntity);        } catch (Exception e) {
               e.printStackTrace();        }        return sendHttpPost(httpPost);    }    /**     * 发送 post请求     * @param httpUrl 地址     * @param maps 参数     */    public String sendHttpPost(String httpUrl, Map
   
     maps) {
           HttpPost httpPost = new HttpPost(httpUrl);        // 创建参数队列        List
    
      nameValuePairs = new ArrayList
     
      ();        for (String key : maps.keySet()) {
               nameValuePairs.add(new BasicNameValuePair(key, maps.get(key)));        }        try {
               httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "UTF-8"));        } catch (Exception e) {
               e.printStackTrace();        }        return sendHttpPost(httpPost);    }    /**     * 发送Post请求     * @param httpPost     * @return     */    private String sendHttpPost(HttpPost httpPost) {
           CloseableHttpClient httpClient = null;        CloseableHttpResponse response = null;        HttpEntity entity = null;        String responseContent = null;        try {
               // 创建默认的httpClient实例.            httpClient = HttpClients.createDefault();            httpPost.setConfig(requestConfig);            // 执行请求            response = httpClient.execute(httpPost);            entity = response.getEntity();            responseContent = EntityUtils.toString(entity, "UTF-8");        } catch (Exception e) {
               e.printStackTrace();        } finally {
               try {
                   // 关闭连接,释放资源                if (response != null) {
                       response.close();                }                if (httpClient != null) {
                       httpClient.close();                }            } catch (IOException e) {
                   e.printStackTrace();            }        }        return responseContent;    }    /**     * 发送 get请求     * @param httpUrl     */    public String sendHttpGet(String httpUrl) {
           HttpGet httpGet = new HttpGet(httpUrl);        return sendHttpGet(httpGet);    }    /**     * 发送Get请求     * @param httpGet     * @return     */    public String sendHttpGet(HttpGet httpGet) {
           CloseableHttpClient httpClient = null;        CloseableHttpResponse response = null;        HttpEntity entity = null;        String responseContent = null;        try {
               // 创建默认的httpClient实例.            httpClient = HttpClients.createDefault();            httpGet.setConfig(requestConfig);            // 执行请求            response = httpClient.execute(httpGet);            entity = response.getEntity();            responseContent = EntityUtils.toString(entity, "UTF-8");        } catch (Exception e) {
               e.printStackTrace();        } finally {
               try {
                   // 关闭连接,释放资源                if (response != null) {
                       response.close();                }                if (httpClient != null) {
                       httpClient.close();                }            } catch (IOException e) {
                   e.printStackTrace();            }        }        return responseContent;    }}
     
    
   

客户端

import org.apache.http.client.methods.HttpGet;/** * @author jerryjin * @Classname HttpClinetDemo * @Date 2021-04-11 12:36 */public class HttpClinetDemo {
       public static void main(String[] args) throws CloneNotSupportedException {
           String url = "https://jerryjin.blog.csdn.net/article/details/115766780";        HttpGet get = new HttpGet(url);        get.addHeader("User-Agent", " Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36");                String s = HttpClientUtil.getInstance().sendHttpGet(get);        System.out.println(s);    }}

转载地址：https://jerryjin.blog.csdn.net/article/details/115766780 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！