HttpClient4.X发送带参数的Get请求

原地址：http://blog.youkuaiyun.com/zknxx/article/details/51598852

HttpClient 是apache 组织下面的一个用于处理HTTP 请求和响应的开源工具。所用jar包为httpclient-4.3.6.jar、httpcore-4.3.3.jar、httpmime-4.3.6.jar、commons-codec-1.6.jar。

发送Get请求代码如下：

[java]  view plain  copy

1. package com.zkn.newlearn.httpclient;  
2.   
3. import java.io.BufferedReader;  
4. import java.io.IOException;  
5. import java.io.InputStream;  
6. import java.io.InputStreamReader;  
7. import java.util.List;  
8.   
9. import org.apache.http.Consts;  
10. import org.apache.http.HttpEntity;  
11. import org.apache.http.NameValuePair;  
12. import org.apache.http.ParseException;  
13. import org.apache.http.client.entity.UrlEncodedFormEntity;  
14. import org.apache.http.client.methods.CloseableHttpResponse;  
15. import org.apache.http.client.methods.HttpGet;  
16. import org.apache.http.impl.client.CloseableHttpClient;  
17. import org.apache.http.impl.client.HttpClients;  
18. import org.apache.http.message.BasicNameValuePair;  
19. import org.apache.http.util.EntityUtils;  
20.   
21. import com.google.common.collect.Lists;  
22.   
23. public class HttpClientTest02 {  
24.   
25.     public static void main(String[] args) {  
26.         CloseableHttpClient httpClient = HttpClients.createDefault();  
27.         CloseableHttpResponse response = null;  
28.         InputStream is = null;  
29.         String url = "http://localhost:8080/MyWebxTest/getCityByProvinceEname.do";  
30.         //封装请求参数  
31.         List<NameValuePair> params = Lists.newArrayList();  
32.         params.add(new BasicNameValuePair("cityEname", "henan"));  
33.         String str = "";  
34.         try {  
35.             //转换为键值对  
36.             str = EntityUtils.toString(new UrlEncodedFormEntity(params, Consts.UTF_8));  
37.             System.out.println(str);  
38.             //创建Get请求  
39.             HttpGet httpGet = new HttpGet(url+"?"+str);  
40.             //执行Get请求，  
41.             response = httpClient.execute(httpGet);  
42.             //得到响应体  
43.             HttpEntity entity = response.getEntity();  
44.             if(entity != null){  
45.                 is = entity.getContent();  
46.                 //转换为字节输入流  
47.                 BufferedReader br = new BufferedReader(new InputStreamReader(is, Consts.UTF_8));  
48.                 String body = null;  
49.                 while((body=br.readLine()) != null){  
50.                     System.out.println(body);  
51.                 }  
52.             }  
53.         } catch (ParseException e) {  
54.             e.printStackTrace();  
55.         } catch (IOException e) {  
56.             e.printStackTrace();  
57.         } finally{  
58.             //关闭输入流，释放资源  
59.             if(is != null){  
60.                 try {  
61.                     is.close();  
62.                 } catch (IOException e) {  
63.                     e.printStackTrace();  
64.                 }  
65.             }  
66.             //消耗实体内容  
67.             if(response != null){  
68.                 try {  
69.                     response.close();  
70.                 } catch (IOException e) {  
71.                     e.printStackTrace();  
72.                 }  
73.             }  
74.             //关闭相应 丢弃http连接  
75.             if(httpClient != null){  
76.                 try {  
77.                     httpClient.close();  
78.                 } catch (IOException e) {  
79.                     e.printStackTrace();  
80.                 }  
81.             }  
82.         }  
83.           
84.     }  
85. }