java使用httpcomponents发送get请求

一、适用场景

　　在ESTful webservice中，get方法一般都是用来获取数据。我们可以使用httpcomponents组件来完成调用。

　　如我们需要发起get请求，携带的参数都是附加到请求的url后面。

　　url："http://www.xxxxx.com/message?id=000010"

二、代码示例

 package com.demo.test;

 import java.io.IOException;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpStatus;
 import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.util.EntityUtils;

 public class Test2 {

     public static String sendInfo(String url, String param) {
         String geturl = String.format("%s?id=%s", url, param);
         CloseableHttpClient client = HttpClients.createDefault();
         HttpGet get = new HttpGet(geturl);
         String responseContent = null; // 响应内容
         CloseableHttpResponse response = null;
         try {
             response = client.execute(get);
             HttpEntity entity = response.getEntity();// 响应体
             if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {// 正确返回
                 responseContent = EntityUtils.toString(entity, "UTF-8");
             }
         } catch (ClientProtocolException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
             try {
                 if (response != null)
                     response.close();
                 if (client != null)
                     client.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
         }
         return responseContent;
     }

     public static void main(String[] args) {
         String param = "000010";
         String result = sendInfo("http://www.xxxxx.com/message", param);
         System.out.println(result);
     }
 }

　　请求成功后，后天会打印返回的信息。