HttpClientUtil 工具类 实现跨域请求数据

 package com.xxx.common.util;

 import java.io.IOException;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import org.apache.http.NameValuePair;
 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.utils.URIBuilder;
 import org.apache.http.entity.ContentType;
 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;

 public class HttpClientUtil {

     public static String doGet(String url, Map<String, String> param) {
         // 创建Httpclient对象
         CloseableHttpClient httpclient = HttpClients.createDefault();
         String resultString = "";
         CloseableHttpResponse response = null;
         try {
             // 创建uri
             URIBuilder builder = new URIBuilder(url);
             if (param != null) {
                 for (String key : param.keySet()) {
                     builder.addParameter(key, param.get(key));
                 }
             }
             URI uri = builder.build();

             // 创建http GET请求
             HttpGet httpGet = new HttpGet(uri);

             // 执行请求
             response = httpclient.execute(httpGet);
             // 判断返回状态是否为200
             if (response.getStatusLine().getStatusCode() == 200) {
                 resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 if (response != null) {
                     response.close();
                 }
                 httpclient.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return resultString;
     }

     public static String doGet(String url) {
         return doGet(url, null);
     }

     public static String doPost(String url, Map<String, String> param) {
         // 创建Httpclient对象
         CloseableHttpClient httpClient = HttpClients.createDefault();
         CloseableHttpResponse response = null;
         String resultString = "";
         try {
             // 创建Http Post请求
             HttpPost httpPost = new HttpPost(url);
             // 创建参数列表
             if (param != null) {
                 List<NameValuePair> paramList = new ArrayList<>();
                 for (String key : param.keySet()) {
                     paramList.add(new BasicNameValuePair(key, param.get(key)));
                 }
                 // 模拟表单
                 UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList, "utf-8");
                 httpPost.setEntity(entity);
             }
             // 执行http请求
             response = httpClient.execute(httpPost);
             resultString = EntityUtils.toString(response.getEntity(), "utf-8");
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 response.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return resultString;
     }

     public static String doPost(String url) {
         return doPost(url, null);
     }

     /**
      * 请求的参数类型为json
      * @param url
      * @param json
      * @return
      * {username:"",pass:""}
      */
     public static String doPostJson(String url, String json) {
         // 创建Httpclient对象
         CloseableHttpClient httpClient = HttpClients.createDefault();
         CloseableHttpResponse response = null;
         String resultString = "";
         try {
             // 创建Http Post请求
             HttpPost httpPost = new HttpPost(url);
             // 创建请求内容
             StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
             httpPost.setEntity(entity);
             // 执行http请求
             response = httpClient.execute(httpPost);
             resultString = EntityUtils.toString(response.getEntity(), "utf-8");
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             try {
                 response.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return resultString;
     }
 }