httpclient模拟post请求json封装表单数据

好长时间不更博了，主要肚子里没什么好墨水，哈哈。废话不说上代码。

     public static String httpPostWithJSON(String url) throws Exception {

         HttpPost httpPost = new HttpPost(url);
         CloseableHttpClient client = HttpClients.createDefault();
         String respContent = null;

 //        json方式
         JSONObject jsonParam = new JSONObject();
         jsonParam.put("name", "admin");
         jsonParam.put("pass", "123456");
         StringEntity entity = new StringEntity(jsonParam.toString(),"utf-8");//解决中文乱码问题
         entity.setContentEncoding("UTF-8");
         entity.setContentType("application/json");
         httpPost.setEntity(entity);
         System.out.println();

 //        表单方式
 //        List<BasicNameValuePair> pairList = new ArrayList<BasicNameValuePair>();
 //        pairList.add(new BasicNameValuePair("name", "admin"));
 //        pairList.add(new BasicNameValuePair("pass", "123456"));
 //        httpPost.setEntity(new UrlEncodedFormEntity(pairList, "utf-8"));   

         HttpResponse resp = client.execute(httpPost);
         if(resp.getStatusLine().getStatusCode() == 200) {
             HttpEntity he = resp.getEntity();
             respContent = EntityUtils.toString(he,"UTF-8");
         }
         return respContent;
     }

     public static void main(String[] args) throws Exception {
         String result = httpPostWithJSON("http://localhost:8080/hcTest2/Hc");
         System.out.println(result);
     }

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。

 public class HcServlet extends HttpServlet {
     private static final long serialVersionUID = 1L;

     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
         doPost(request, response);
     }

     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         request.setCharacterEncoding("UTF-8");
         response.setContentType("text/html;charset=UTF-8");
         String acceptjson = "";
         User user = new User();
         BufferedReader br = new BufferedReader(new InputStreamReader(
                 (ServletInputStream) request.getInputStream(), "utf-8"));
         StringBuffer sb = new StringBuffer("");
         String temp;
         while ((temp = br.readLine()) != null) {
             sb.append(temp);
         }
         br.close();
         acceptjson = sb.toString();
         if (acceptjson != "") {
             JSONObject jo = JSONObject.parseObject(acceptjson);
             user.setUsername(jo.getString("name"));
             user.setPassword(jo.getString("pass"));
         }  

         request.setAttribute("user", user);
         request.getRequestDispatcher("/message.jsp").forward(request, response);
     }
 }

代码比较简陋，只是用于测试。希望能够有所收获。