java 客户端发起http请求

 package com.mall.core.utils.http;

 import org.apache.commons.lang.StringUtils;
 import org.apache.http.HttpResponse;
 import org.apache.http.HttpStatus;
 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.*;
 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;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

 import javax.servlet.http.HttpServletRequest;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 /**
  * Created by admin on 2017/2/22.
　　　　自己写了一个工具类 把常见的几种http请求方法 封装起来
  */
 public class HttpUtils {

     private static final Logger logger = LogManager.getLogger(HttpUtils.class);
     private static final RequestConfig requestConfig = RequestConfig.custom()
             .setConnectTimeout(20000).setConnectionRequestTimeout(10000)
             .setSocketTimeout(20000).build();

     /**
      * Http Get
      *
      * @param url    请求路径
      * @param params 参数
      * @return http响应状态及json结果
      */
     public static HttpResult doGet(String url, Map<String, String> params) {
         CloseableHttpClient httpClient = HttpClients.createDefault();
         url = contactUrl(url, params);
         HttpGet httpGet = new HttpGet(url.replace(" ", ""));
         return executeRequest(httpClient, httpGet);
     }

     /**
      * Http Post
      *
      * @param url    请求路径
      * @param params 参数
      * @return http响应状态及json结果
      */
     public static HttpResult doPost(String url, Map<String, String> params) {
         CloseableHttpClient httpClient = HttpClients.createDefault();
         HttpPost httpPost = new HttpPost(url);
         List<NameValuePair> pairs = new ArrayList<>();
         Set<String> keys = params.keySet();
         for (String key : keys) {
             String value = params.get(key);
             pairs.add(new BasicNameValuePair(key, value));
         }
         return executeRequest(httpClient, httpPost, pairs);
     }

     /**
      * Http Put
      *
      * @param url    请求路径
      * @param params 参数
      * @return http响应状态及json结果
      */
     public static HttpResult doPut(String url, Map<String, String> params) {
         CloseableHttpClient httpClient = HttpClients.createDefault();
         url = contactUrl(url, params);
         HttpPut httpPut = new HttpPut(url);
         return executeRequest(httpClient, httpPut);
     }

     /**
      * Http Delete
      *
      * @param url    请求路径
      * @param params 参数
      * @return http响应状态及json结果
      */
     public static HttpResult doDelete(String url, Map<String, String> params) {
         CloseableHttpClient httpClient = HttpClients.createDefault();
         url = contactUrl(url, params);
         HttpDelete httpDelete = new HttpDelete(url);
         return executeRequest(httpClient, httpDelete);
     }

     /**
      * 拼装url
      *
      * @param url    url
      * @param params 参数
      * @return
      */
     private static String contactUrl(String url, Map<String, String> params) {
         if (params != null) {
             String param = "";
             Set<String> keys = params.keySet();
             for (String key : keys) {
                 String value = params.get(key);
                 if (value == null || value.equals("null")) {
                     continue;
                 }
                 param += key + "=" + value + "&";
             }
             if (!param.equals("")) {
                 url += "?" + param.substring(0, param.length() - 1);
             }
         }
         return url;
     }
     private static String contactUrl_(String url, Map<String, Object> params){
         if(params != null){
             String param = "";
             Set<String> keys = params.keySet();
             for(String key : keys){
                 Object value = params.get(key);
                 if(value == null || value.equals("null")){
                     continue;
                 }
                 param += key + "=" + value + "&";
             }
             if(!param.equals("")){
                 url += "?" + param.substring(0, param.length() - 1);
             }
         }
         return url;
     }

     public static String getFullPath(HttpServletRequest request) {
         String basePath = request.getRequestURL().toString();
         String queryString = request.getQueryString();
         if (StringUtils.isNotEmpty(queryString)) {
             queryString = "?" + queryString;
         } else {
             queryString = "";
         }

         return basePath + queryString;
     }

     /**
      * 执行GET/PUT/DELETE请求
      *
      * @param httpClient
      * @param request
      * @return
      */
     private static HttpResult executeRequest(CloseableHttpClient httpClient, HttpRequestBase request) {
         HttpResult result = null;
         request.setConfig(requestConfig);
         try {
             HttpResponse response = httpClient.execute(request);
             int code = response.getStatusLine().getStatusCode();
             result = new HttpResult();
             result.setStatus(code);
             if (code == HttpStatus.SC_OK) {
                 result.setResponse(EntityUtils.toString(response.getEntity()));
             }
         } catch (Exception e) {
             logger.error("=========GET/PUT/DELETE请求异常：" + request.getURI(), e);
             return result;
         } finally {
             try {
                 httpClient.close();
             } catch (IOException e) {
                 logger.error("=========GET/PUT/DELETE请求连接关闭异常：" + request.getURI(), e);
             }
         }
         logger.debug("========GET/PUT/DELETE请求响应：" + request.getURI() + "\n" + result);
         return result;
     }

     /**
      * 执行POST请求
      *
      * @param httpClient
      * @param request
      * @param pairs
      * @return
      */
     private static HttpResult executeRequest(CloseableHttpClient httpClient, HttpEntityEnclosingRequestBase request, List<NameValuePair> pairs) {
         HttpResult result = null;
         request.setConfig(requestConfig);
         try {
             StringEntity entity;
             if (pairs.size() == 1 && pairs.get(0).getName().equals("json")) {
                 entity = new StringEntity(pairs.get(0).getValue(), "UTF-8");
                 entity.setContentType("application/json");
             } else {
                 entity = new UrlEncodedFormEntity(pairs, "UTF-8");
             }
             request.setEntity(entity);
             HttpResponse response = httpClient.execute(request);
             int code = response.getStatusLine().getStatusCode();
             result = new HttpResult();
             result.setStatus(code);
             if (code == HttpStatus.SC_OK) {
                 result.setResponse(EntityUtils.toString(response.getEntity()));
             }
         } catch (Exception e) {
             logger.error("=========POST请求异常：" + request.getURI(), e);
             return result;
         } finally {
             try {
                 httpClient.close();
             } catch (IOException e) {
                 logger.error("=========POST请求连接关闭异常：" + request.getURI(), e);
             }
         }
         logger.debug("========POST请求响应：" + request.getURI() + "\n" + result);
         return result;
     }
 }

顺便把 响应的那个HttpResult 类也贴下

public class HttpResult {

    private int status;
    private String response;

    public HttpResult() {
        status = 400;
    }

    public HttpResult(int status, String response) {
        this.status = status;
        this.response = response;
    }

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public String getResponse() {
        return response;
    }

    public void setResponse(String response) {
        this.response = response;
    }

    @Override
    public String toString() {
        return "HttpResult{" +
                "status=" + status +
                ", response='" + response + '\'' +
                '}';
    }
}