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");//解決中文亂碼問題      entity.setContentEncoding("UTF-8");      entity.setContentType("application/json");      httpPost.setEntity(entity);    System.out.println();      //    表單方式//    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);  }

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);  }}