Stack Exchange
ClassNotFoundException in JSON Parsing by servlet
I am new in json and I am getting a  request in json object format. 
       {"login_detail":[{"password":"world","username":"hello"}]}

I want to parse it by servlet and my code is as follow-
     public class LoginServlet extends HttpServlet{

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
    //String json=request.getParameter("x");
   try {
        String jsonreq=request.getParameter("x");

        System.out.println(jsonreq);



        JSONArray outerArray = (JSONArray) JSONSerializer.toJSON(jsonreq);
        JSONObject json1 = (JSONObject) outerArray.get(0);
        JSONArray jarray1 = json1.getJSONArray("login_detail");
        for (int i = 0; i < jarray1.size(); i++)
        {
          JSONObject hotel = jarray1.getJSONObject(i);
          String user = hotel.getString("pasword");
          System.out.println(user);
          String pass=hotel.getString("username");
          System.out.println(pass);
        }

        out.print(jsonreq);

    }catch(Exception e){
        System.out.println("inside exception");
        e.printStackTrace();
    }
    finally {            
        out.close();
    }


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

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

public String getServletInfo() {
    return "Short description";
}}

But i am getting a exception
       Sep 09, 2013 4:57:52 PM org.apache.catalina.core.StandardWrapperValve invoke
       SEVERE: Servlet.service() for servlet login threw exception
       java.lang.ClassNotFoundException:            org.apache.commons.lang.exception.NestableRuntimeException
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1850)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:890)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1354)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
at com.serverside.LoginServlet.processRequest(LoginServlet.java:40)
at com.serverside.LoginServlet.doPost(LoginServlet.java:72)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
at java.lang.Thread.run(Thread.java:722)

Now i am using json-lib 2.2.2 jar file.There is no any issue in receiving request from android client . I cant understand if JSONObject parametrize constructor work perfectly in ANDROID then why it is not working for servlet.?? What is problem i can't understand. If anybody will help me i will be really thankful.

You have to all dependency libraries, If you miss these, you will get runtime exception.
You are missing org.apache.commons
btw, change hotel.getString("pasword"); to hotel.getString("password");

i have add all the commong jar sorry i am getting same problem

finally i have solve my problem see the code 
 try {
       String data=request.getParameter("x");
       System.out.println("received data : "+data);
       JSONObject myjson=new JSONObject(data);
       JSONArray json_array=myjson.getJSONArray("login_detail");
       // return simple array with [] bracket
       System.out.println("json_array "+json_array);
       int size=json_array.length();
       ArrayList<JSONObject> arrays=new ArrayList<JSONObject>();
       for(int i=0;i<size;i++){
           JSONObject another_json_object=json_array.getJSONObject(i);
           arrays.add(another_json_object);
       }
       JSONObject[] jsons=new JSONObject[arrays.size()];
       arrays.toArray(jsons);
    // return simple array with [] bracket
       System.out.println("arrays :"+arrays);
    // return simple array and filter [] when we call get(index)
       System.out.println("0 index : "+arrays.get(0));
       //System.out.println("1 index : "+arrays.get(1));

       //here we are accessing value using key of the array at 0 index
       // we can do same for next index --> get(index).get("key")
       System.out.println(arrays.get(0).get("username")+"   
       "+arrays.get(0).getString("password"));

    }catch(Exception e){
        System.out.println("inside exception");
        e.printStackTrace();
    }


The most likely explanation is that the JAR that defines the Apache NestableRuntimeException is missing from your webapp's WAR file.
According to http://www.findjar.com, there are lots of JAR file that could supply that dependency, but the most likely one is one of the commons-lang-x.x.jar files; e.g. commons-lang-2.3.jar
If you are building your WAR file using Maven, just add the relevant dependency to the POM file.  Otherwise, download the JAR by hand and add it to the "/WEB-INF/lib" directory of your WAR file.

finally i got solution of my problem

You can download the Apache Commons Lang and place the jar file under /WEB-INF/lib.
It should solve the problem.

the http://json-lib.sourceforge.net/dependencies.html has all the dependencies you need to add.

confirm that you liability jars had been copied to WEB-INF/lib folder... I guess so.
