httpclient模拟post请求json封装表单数据

 1     public static String httpPostWithJSON(String url) throws Exception {
 2
 3         HttpPost httpPost = new HttpPost(url);
 4         CloseableHttpClient client = HttpClients.createDefault();
 5         String respContent = null;
 6
 7 //        json方式
 8         JSONObject jsonParam = new JSONObject();
 9         jsonParam.put("name", "admin");
10         jsonParam.put("pass", "123456");
11         StringEntity entity = new StringEntity(jsonParam.toString(),"utf-8");//解决中文乱码问题
12         entity.setContentEncoding("UTF-8");
13         entity.setContentType("application/json");
14         httpPost.setEntity(entity);
15         System.out.println();
16
17
18 //        表单方式
19 //        List<BasicNameValuePair> pairList = new ArrayList<BasicNameValuePair>();
20 //        pairList.add(new BasicNameValuePair("name", "admin"));
21 //        pairList.add(new BasicNameValuePair("pass", "123456"));
22 //        httpPost.setEntity(new UrlEncodedFormEntity(pairList, "utf-8"));
23
24
25         HttpResponse resp = client.execute(httpPost);
26         if(resp.getStatusLine().getStatusCode() == 200) {
27             HttpEntity he = resp.getEntity();
28             respContent = EntityUtils.toString(he,"UTF-8");
29         }
30         return respContent;
31     }
32
33
34     public static void main(String[] args) throws Exception {
35         String result = httpPostWithJSON("http://localhost:8080/hcTest2/Hc");
36         System.out.println(result);
37     }

post方式 就要考虑提交的表单内容怎么传输了。本文name和pass就是表单的值了。

封装表单属性可以用json也可以用传统的表单，如果是传统表单的话 要注意，也就是在上边代码注释那部分。用这种方式的话在servlet里也就是数据处理层可以通过request.getParameter(”string“)直接获取到属性值。就是相比json这种要简单一点，不过在实际开发中一般都是用json做数据传输的。用json的话有两种选择一个是阿里巴巴的fastjson还有一个就是谷歌的gson。fastjson相比效率比较高，gson适合解析有规律的json数据。博主这里用的是fastjson。还有用json的话在数据处理层要用流来读取表单属性，这就是相比传统表单多的一点内容。代码下边已经有了。

 1 public class HcServlet extends HttpServlet {
 2     private static final long serialVersionUID = 1L;
 3
 4     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 5         doPost(request, response);
 6     }
 7
 8
 9     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
10
11         request.setCharacterEncoding("UTF-8");
12         response.setContentType("text/html;charset=UTF-8");
13         String acceptjson = "";
14         User user = new User();
15         BufferedReader br = new BufferedReader(new InputStreamReader(
16                 (ServletInputStream) request.getInputStream(), "utf-8"));
17         StringBuffer sb = new StringBuffer("");
18         String temp;
19         while ((temp = br.readLine()) != null) {
20             sb.append(temp);
21         }
22         br.close();
23         acceptjson = sb.toString();
24         if (acceptjson != "") {
25             JSONObject jo = JSONObject.parseObject(acceptjson);
26             user.setUsername(jo.getString("name"));
27             user.setPassword(jo.getString("pass"));
28         }
29
30         request.setAttribute("user", user);
31         request.getRequestDispatcher("/message.jsp").forward(request, response);
32     }
33 }

原文地址：https://www.cnblogs.com/cristin/p/8427667.html