Android出勤应用程序JSON解析错误

Question

I managed to solve all problems except the JSONException error. I know that my code is not efficient and it can be improved by using asynctask etc but for now solving this error is on top of my priority list so please help me out with this.

I am sharing all required codes and details.

MSRITShowAttendance.java:

package com.vasan.msritstudentservice;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MSRITShowAttendance extends Activity
{
JSONParser JP = new JSONParser();

ProgressDialog PDial = null;

String Pswd, stpwd;

Button Attendance;
EditText AIDEdit, SPEdit;
TextView StIDView, SuIDView, TCView, CAView, PView, CView;

private static String url_att_view = "http://10.0.2.2/MSRIT_Student_Info_Handles/MSRIT_retrieve_particular_attendance.php";

private static final String TAG_ATTENDANCE_SUCCESS = "success";
    private static final String TAG_ATTENDANCE_ARRAY = "attendance";
    private static final String TAG_ATTENDANCE_STUDID = "studid";
    private static final String TAG_ATTENDANCE_SUBID = "subid";
    private static final String TAG_ATTENDANCE_TOTALCLASSES = "totalclasses";
    private static final String TAG_ATTENDANCE_ATTENDEDCLASSES = "attendedclasses";
    private static final String TAG_ATTENDANCE_PERCENTAGE = "percentage";
    private static final String TAG_ATTENDANCE_COMMENTS = "comments";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.msrit_student_details);
    Attendance = (Button) findViewById(R.id.ViewAttendance); 
    AIDEdit = (EditText) findViewById(R.id.AttIDEdit);
    SPEdit = (EditText) findViewById(R.id.PasswordEdit);
    StIDView = (TextView) findViewById(R.id.StudentIDView);
    SuIDView = (TextView) findViewById(R.id.SubjectIDView);
    TCView = (TextView) findViewById(R.id.TotalClassesView);
    CAView = (TextView) findViewById(R.id.ClassesAttendedView);
    PView = (TextView) findViewById(R.id.PercentageView);
    CView = (TextView) findViewById(R.id.CommentView);

Attendance.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            PDial = ProgressDialog.show(MSRITShowAttendance.this, "", "Validating user.Please wait...", true);
            new Thread(new Runnable() 
            {
                public void run()
                {
                    showDetails();
                }
            }).start();

        }
    });
}       

void showDetails()
{
    try
    {
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("attid",AIDEdit.getText().toString().trim())); 
        params.add(new BasicNameValuePair("studpwd",SPEdit.getText().toString().trim()));
        JSONObject json = JP.makeHttpRequest(url_att_view, "GET", params);
        int success = json.getInt(TAG_ATTENDANCE_SUCCESS);  
        new Thread(new Runnable(){
            public void run()
            {
                PDial.dismiss();
            }
        }).start();
        if (success == 1)
        {
            runOnUiThread(new Runnable()
            {
                public void run()
                {
                    Toast.makeText(getApplicationContext(),"Login Credentials Verified!!", Toast.LENGTH_SHORT).show();
                }
            });
            JSONArray attendance = json.getJSONArray(TAG_ATTENDANCE_ARRAY);

                JSONObject c = attendance.getJSONObject(0);

                String TC = ""+(c.getInt(TAG_ATTENDANCE_TOTALCLASSES));
                String AC = ""+(c.getInt(TAG_ATTENDANCE_ATTENDEDCLASSES));
                String PCNTG = ""+(c.getInt(TAG_ATTENDANCE_PERCENTAGE));
                String CMTS = ""+(c.getInt(TAG_ATTENDANCE_COMMENTS));
                StIDView.setText(("Student ID: "+c.getString(TAG_ATTENDANCE_STUDID))); 
                SuIDView.setText(("Subject ID: "+c.getString(TAG_ATTENDANCE_SUBID)));
                TCView.setText(("Total Classes: "+TC.trim())); 
                CAView.setText(("Classes Attended: "+AC.trim())); 
                PView.setText(("Percentage: "+PCNTG.trim())); 
                CView.setText(("Comments: "+CMTS.trim())); 

        }
        else
        {
            showAlert();                
        }   
    }
    catch(JSONException E)
    {
        PDial.dismiss();
        E.printStackTrace();
    }       
}
void showAlert()
{
    MSRITShowAttendance.this.runOnUiThread(new Runnable()
    {
        public void run()
        {
            AlertDialog.Builder builder = new AlertDialog.Builder(MSRITShowAttendance.this);
            builder.setTitle("Database Error:Record not found.");
            builder.setMessage("To User:Please check if you have registered.")  
                   .setCancelable(false)
                   .setPositiveButton("OK", new DialogInterface.OnClickListener()
                   {
                       public void onClick(DialogInterface dialog, int id)
                       {

                       }
                   });                     
            AlertDialog alert = builder.create();
            alert.show();               
        }
    });
  }
}

JSONParser.java:

 package com.vasan.msritstudentservice;

    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.UnsupportedEncodingException;
    import java.util.List;

    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.NameValuePair;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.entity.UrlEncodedFormEntity;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.client.utils.URLEncodedUtils;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.json.JSONException;
    import org.json.JSONObject;

    import android.util.Log;

    public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    // function get json from url
    // by making HTTP POST or GET mehtod
    public JSONObject makeHttpRequest(String url, String method,
            List<NameValuePair> params) {

        // Making HTTP request
        try {

            // check for request method
            if(method.equals("POST")){
                // request method is POST
                // defaultHttpClient
                DefaultHttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(url);
                httpPost.setEntity(new UrlEncodedFormEntity(params));

                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            }else if(method.equals("GET")){
                // request method is GET
                DefaultHttpClient httpClient = new DefaultHttpClient();
                String paramString = URLEncodedUtils.format(params, "utf-8");
                url += "?" + paramString;
                HttpGet httpGet = new HttpGet(url);

                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }           


        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
            Log.e("The Resultant String is",json);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser results",json);
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

      }
   }

MSRIT_Retrieve_Particular_Attendance.php:

<?php
$response = array();
include 'MSRIT_db_connect.php';
$db = new DB_CONNECT();
if (isset($_GET["attid"]) && $_GET["studpwd"])
{
    $attid = $_GET['attid'];
$studpwd = $_GET['studpwd'];
    $result = mysql_query("SELECT * FROM attendance, studentdetails WHERE attid =   '$attid' AND studpwd = '$studpwd' AND attendance.studid = studentdetails.studid");
    if (!empty($result))
{
        if (mysql_num_rows($result) > 0)
    {
            $result = mysql_fetch_array($result);
            $attendance = array();
            $attendance["attid"] = $result["attid"];
            $attendance["studid"] = $result["studid"];
            $attendance["subid"] = $result["subid"];
            $attendance["totalclasses"] = $result["totalclasses"];
            $attendance["attendedclasses"] = $result["attendedclasses"];
            $attendance["percentage"] = $result["percentage"];
    $attendance["comments"] = $result["comments"];
            $response["success"] = 1;
            $response["attendance"] = array();
            array_push($response["attendance"], $attendance);
            echo json_encode($response);
        }
    else
    {
            $response["success"] = 0;
            $response["message"] = "No attendance found";
            echo json_encode($response);
        }
    }
else
{
        $response["success"] = 0;
        $response["message"] = "No attendance found";
        echo json_encode($response);
    }
}
else
{
    $response["success"] = 0;
    $response["message"] = "Required field(s) is missing";
    echo json_encode($response);
}
?>

LogCat:

03-27 08:18:36.672: E/The Resultant String is(776): <br />
03-27 08:18:36.672: E/The Resultant String is(776): <font size='1'><table    class='xdebug-error xe-notice' dir='ltr' border='1' cellspacing='0' cellpadding='1'>
03-27 08:18:36.672: E/The Resultant String is(776): <tr><th align='left'    bgcolor='#f57900' colspan="5"><span style='background-color: #cc0000; color: #fce94f; font-size: x-large;'>( ! )</span> Notice: Undefined index: comments in   C:\wamp\www\MSRIT_Student_Info_Handles\MSRIT_retrieve_particular_attendance.php on line <i>22</i></th></tr>
03-27 08:18:36.672: E/The Resultant String is(776): <tr><th align='left' bgcolor='#e9b96e' colspan='5'>Call Stack</th></tr>
03-27 08:18:36.672: E/The Resultant String is(776): <tr><th align='center' bgcolor='#eeeeec'>#</th><th align='left' bgcolor='#eeeeec'>Time</th><th align='left' bgcolor='#eeeeec'>Memory</th><th align='left' bgcolor='#eeeeec'>Function</th><th align='left' bgcolor='#eeeeec'>Location</th></tr>
03-27 08:18:36.672: E/The Resultant String is(776): <tr><td bgcolor='#eeeeec' align='center'>1</td><td bgcolor='#eeeeec' align='center'>0.0005</td><td bgcolor='#eeeeec' align='right'>686336</td><td bgcolor='#eeeeec'>{main}(  )</td><td title='C:\wamp\www\MSRIT_Student_Info_Handles\MSRIT_retrieve_particular_attendance.php' bgcolor='#eeeeec'>..\MSRIT_retrieve_particular_attendance.php<b>:</b>0</td></tr>
03-27 08:18:36.672: E/The Resultant String is(776): </table></font>
03-27 08:18:36.672: E/The Resultant String is(776): {"success":1,"attendance":[{"attid":"2","studid":"1MS10IS049","subid":"1","totalclasses":"44","attendedclasses":"0","percentage":"0.00","comments":null}]}
03-27 08:18:36.732: E/JSON Parser results(776): <br />
03-27 08:18:36.732: E/JSON Parser results(776): <font size='1'><table class='xdebug-error xe-notice' dir='ltr' border='1' cellspacing='0' cellpadding='1'>
03-27 08:18:36.732: E/JSON Parser results(776): <tr><th align='left' bgcolor='#f57900' colspan="5"><span style='background-color: #cc0000; color: #fce94f; font-size: x-large;'>( ! )</span> Notice: Undefined index: comments in C:\wamp\www\MSRIT_Student_Info_Handles\MSRIT_retrieve_particular_attendance.php on line <i>22</i></th></tr>
03-27 08:18:36.732: E/JSON Parser results(776): <tr><th align='left' bgcolor='#e9b96e' colspan='5'>Call Stack</th></tr>
03-27 08:18:36.732: E/JSON Parser results(776): <tr><th align='center' bgcolor='#eeeeec'>#</th><th align='left' bgcolor='#eeeeec'>Time</th><th align='left' bgcolor='#eeeeec'>Memory</th><th align='left' bgcolor='#eeeeec'>Function</th><th align='left' bgcolor='#eeeeec'>Location</th></tr>
03-27 08:18:36.732: E/JSON Parser results(776): <tr><td bgcolor='#eeeeec' align='center'>1</td><td bgcolor='#eeeeec' align='center'>0.0005</td><td bgcolor='#eeeeec' align='right'>686336</td><td bgcolor='#eeeeec'>{main}(  )</td><td title='C:\wamp\www\MSRIT_Student_Info_Handles\MSRIT_retrieve_particular_attendance.php' bgcolor='#eeeeec'>..\MSRIT_retrieve_particular_attendance.php<b>:</b>0</td></tr>
03-27 08:18:36.732: E/JSON Parser results(776): </table></font>
03-27 08:18:36.732: E/JSON Parser results(776): {"success":1,"attendance":[{"attid":"2","studid":"1MS10IS049","subid":"1","totalclasses":"44","attendedclasses":"0","percentage":"0.00","comments":null}]}
03-27 08:18:36.732: E/JSON Parser(776): Error parsing data org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
03-27 08:18:36.742: W/System.err(776): org.json.JSONException: No value for attendance
03-27 08:18:36.752: W/System.err(776):  at org.json.JSONObject.get(JSONObject.java:354)
03-27 08:18:36.752: W/System.err(776):  at org.json.JSONObject.getJSONArray(JSONObject.java:544)
03-27 08:18:36.762: W/System.err(776):  at com.vasan.msritstudentservice.MSRITShowAttendance.showDetails(MSRITShowAttendance.java:104)
03-27 08:18:36.852: W/System.err(776):  at com.vasan.msritstudentservice.MSRITShowAttendance$1$1.run(MSRITShowAttendance.java:72)
03-27 08:18:36.852: W/System.err(776):  at java.lang.Thread.run(Thread.java:856)

Answer 1

The Problem is your "JSON"-String, as it tells in the Logcat.

Your "json"-string contains HTML-Tags, like br or font size ='1' etc.

Only the last Line of the String-Result in your Logcat is valid JSON. But you try to parse the whole string, and not only the JSON.

//EDIT

This Error occures - Like D_Vaibhav ツ told - because your Webserver returns an Error first:

Notice: Undefined index: comments in C:\\wamp\\www\\MSRIT_Student_Info_Handles\\MSRIT_retrieve_particular_attendance.php on line 22

Answer 2

JSON Parsing error occurs when your web service don't return valid JSON. In this case your server returning HTML contents along with JSON. So you have something wrong at web service side.

by looking at your PHP code You have error at Line 22 in your MSRIT_retrieve_particular_attendance.php

Notice: Undefined index: comments in

C:\\wamp\\www\\MSRIT_Student_Info_Handles\\MSRIT_retrieve_particular_attendance.php on line 22

//this is Line 22. you are not getting anything named result["comments"]; from your database query Result I think

$attendance["comments"] = $result["comments"];

your result not returning column named "comments"

you can check in that PHP code, I suggest you turn off the warnings from your PHP side, as it may not affect your final result

Here is the link that will help you to do that