通过java.net.URLConnection发送HTTP请求的方法

最近项目中有用到与外围系统对接, 总结下通过java.net.URLConnection发送HTTP请求的方法。

参考博客：http://www.cnblogs.com/nick-huang/p/3859353.html

由于项目较小，并且只查询一个外部接口数据，采用了简单的get请求；

完整代码如下：

 1 package com.ruoyi.api;
 2 
 3 import javax.servlet.http.HttpServletRequest;
 4 
 5 import com.alibaba.fastjson.JSON;
 6 import com.alibaba.fastjson.JSONObject;
 7 import com.ruoyi.api.bus.vo.LinksV2;
 8 import com.ruoyi.api.bus.vo.TopicItemListV2;
 9 import org.apache.commons.collections.CollectionUtils;
10 import org.slf4j.Logger;
11 import org.slf4j.LoggerFactory;
12 import org.springframework.beans.factory.annotation.Value;
13 import org.springframework.stereotype.Controller;
14 import org.springframework.web.bind.annotation.RequestMapping;
15 import org.springframework.web.bind.annotation.ResponseBody;
16 import java.io.BufferedReader;
17 import java.io.IOException;
18 import java.io.InputStreamReader;
19 import java.net.MalformedURLException;
20 import java.net.URL;
21 import java.net.URLConnection;
22 
23 import java.util.ArrayList;
24 import java.util.List;
25 
26 @Controller
27 @RequestMapping("api")
28 public class testcontroller {
29 
30     @Value("${config.getItemInfoUrl}")
31     private String url;
32     private static final Logger LOGGER = LoggerFactory.getLogger(testcontroller.class);
33 
34     @ResponseBody
35     @RequestMapping("/data/getlist")
36     public List<Links>  testlist(HttpServletRequest request) {
37         String jsonInfo = loadJSON(url);
38         List<TopicItemListV2> topicItemListV2s = JSONObject.parseArray(jsonInfo, TopicItemListV2.class);
39         List<Links> linkLists = new ArrayList<>();
40         if (CollectionUtils.isNotEmpty(topicItemListV2s)){
41             for (TopicItemListV2 topicItemList : topicItemListV2s){
42                 Links links = new Links();
43                 links.setPid("0");
44                 links.setCode(String.valueOf(topicItemList.getCode()));
45                 links.setName(topicItemList.getName());
46                 linkLists.add(links);
47                 List<LinksV2> linkV2sss = topicItemList.getLinks();
48                 if (CollectionUtils.isNotEmpty(linkV2sss)){
49                     for (LinksV2 li :linkV2sss){
50                         Links linkvvv = new Links();
51                         linkvvv.setCode(li.getTaskCode());
52                         linkvvv.setName(li.getTaskName());
53                         linkvvv.setPid(String.valueOf(topicItemList.getCode()));
54                         linkLists.add(linkvvv);
55                     }
56                 }
57             }
58         }
59         LOGGER.info(JSON.toJSONString(linkLists));
60         return linkLists;
61     }
62 
63     public  String loadJSON(String url) {
64         StringBuilder json = new StringBuilder();
65         BufferedReader in = null;
66         try {
67             // 创建url对象
68             URL reqUrl = new URL(url);
69             // 打开url链接
70             URLConnection yc = reqUrl.openConnection();
71             // 建立实际对象
72             yc.connect();
73             // 定义BufferedReader 数据流来读取URL的相应,并设置编码方式
74             in = new BufferedReader(new InputStreamReader(
75                     yc.getInputStream(),"utf-8"));
76             String inputLine = null;
77             //读取内容
78             while ((inputLine = in.readLine()) != null) {
79                 json.append(inputLine);
80             }
81         } catch (MalformedURLException e) {
82             LOGGER.error(" error info" + e);
83         } catch (IOException e) {
84             LOGGER.error(" error info" + e);
85         } finally {
86             if (null != in){
87                 try {
88                     in.close();
89                 } catch (IOException e) {
90                     e.printStackTrace();
91                 }
92             }
93         }
94         return json.toString();
95     }
96 }