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 }httpclient模拟post请求json封装表单数据
原文地址：https://www.cnblogs.com/cristin/p/8427667.html