json 将字符串转变为json数据

import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.json.*;public class Testajax extends HttpServlet {/** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. *  * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}/** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. *  * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html");PrintWriter out = response.getWriter();System.out.println("***********");//String result = '{"status": "y"}';//out.print(result) ; try { String str = "{\"status\":\"y\"}";          JSONObject a = new JSONObject(str);        out.print(a) ;        System.out.println(a); // {"c":"d","a":"b"}          System.out.println(a.get("status")); // d  } catch (Exception e) {// TODO: handle exception}out.flush();out.close();}}