错误JSON解析器Android应用

Question

I have a small problem with my code and I can't find why. I get the error parsing data for my email value. The exact error is :

Error parsing data org.json.JSONException: Value Mail of type java.lang.String cannot be converted to JSONObject.

It happens after having the Log.d(request!, starting)

Here are the code.

Activity.java:

package com.example.mysqltest;

import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class ForgotPassword extends Activity implements OnClickListener{

    private EditText email;
    private Button  mForgotPassword;

     // Progress Dialog
    private ProgressDialog pDialog;

    // JSON parser class
    JSONParser jsonParser = new JSONParser();

    //php register script

    private static final String REGISTER_URL = "test";

    //ids
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_MESSAGE = "message";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_forgot_password);

        email = (EditText)findViewById(R.id.emailforf);


        mForgotPassword = (Button)findViewById(R.id.forgotPassword);
        mForgotPassword.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

                new ForgotPass().execute();

    }

    class ForgotPass extends AsyncTask<String, String, String> {


        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(ForgotPassword.this);
            pDialog.setMessage("Retrieving password...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }

        @Override
        protected String doInBackground(String... args) {
            // TODO Auto-generated method stub
             // Check for success tag
            int success;
            String emails = email.getText().toString();
            if (emails instanceof String){
                Log.d("lol","ok");
            }else{
                Log.d("lol","not ok");
            }

            try {
                // Building Parameters
                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(ForgotPassword.this);
                String userpref =  prefs.getString("username","arnaud");
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("emailForgot", emails));
                Log.d(userpref,"lol"); 
                params.add(new BasicNameValuePair("username", userpref));

                Log.d("request!", "starting");

                //Posting user data to script 
                JSONObject json = jsonParser.makeHttpRequest(
                       REGISTER_URL, "POST", params);

                // full json response
                Log.d("Registering attempt", json.toString());

                // json success element
                success = json.getInt(TAG_SUCCESS);
                if (success == 1) {
                    Log.d("User Created!", json.toString());                
                    finish();
                    return json.getString(TAG_MESSAGE);
                }else{
                    Log.d("Registering Failure!", json.getString(TAG_MESSAGE));
                    return json.getString(TAG_MESSAGE);

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;

        }

        protected void onPostExecute(String file_url) {
            // dismiss the dialog once product deleted
            pDialog.dismiss();
            if (file_url != null){
                Toast.makeText(ForgotPassword.this, file_url, Toast.LENGTH_LONG).show();
            }

        }

    }


}

JSONParser.java :

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() {

    }


    public JSONObject getJSONFromUrl(final String url) {

        // Making HTTP request
        try {
            // Construct the client and the HTTP request.
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            // Execute the POST request and store the response locally.
            HttpResponse httpResponse = httpClient.execute(httpPost);
            // Extract data from the response.
            HttpEntity httpEntity = httpResponse.getEntity();
            // Open an inputStream with the data content.
            is = httpEntity.getContent();

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

        try {
            // Create a BufferedReader to parse through the inputStream.
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            // Declare a string builder to help with the parsing.
            StringBuilder sb = new StringBuilder();
            // Declare a string to store the JSON object data in string form.
            String line = null;

            // Build the string until null.
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }

            // Close the input stream.
            is.close();
            // Convert the string builder data to an actual string.
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

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

        // Return the JSON Object.
        return jObj;

    }


    // 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 == "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 == "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();
        } 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", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

Thanks for any help.

[Edit] Here is my web service :

<?php
    try {

        $to = $_POST['emailForgot'];
        $subject = "Test mail";
        $message = "Hello! This is a simple email message.";
        $from = "track_my_mate@example.com";
        $headers = "From:" . $from;
        mail($to,$subject,$message,$headers);
        echo "Mail Sent.";

        $randome = 'pierre';

        $query = "UPDATE 'users' SET 'password' = ? WHERE 'id' = ? ";
        //Again, we need to update our tokens with the actual data:
        $query_params = array(
                ':pass' => $randome,
                ':user' => $_POST['username']
        );

        //time to run our query, and create the user
        try {
            $stmt   = $db->prepare($query);
            $result = $stmt->execute($query_params);
        }
        catch (PDOException $ex) {
            // For testing, you could use a die and message.
            //die("Failed to run query: " . $ex->getMessage());

            //or just use this use this one:
            $response["success"] = 0;
            $response["message"] = "Database Error2. Please Try Again!";
            die(json_encode($response));
        }
    } catch (Exception $e) {
        $response["success"] = 0;
        $response["message"] = "Please Try Again!";
    }

    //If we have made it this far without dying, we have successfully added
    //a new user to our database.  We could do a few things here, such as 
    //redirect to the login page.  Instead we are going to echo out some
    //json data that will be read by the Android application, which will login
    //the user (or redirect to a different activity, I'm not sure yet..)
    $response["success"] = 1;
    $response["message"] = "Password Successfully Changed!";
    try {
        echo json_encode($response);
    } catch (Exception $e) {
        echo ("pierre");
    }

    //for a php webservice you could do a simple redirect and die.
    //header("Location: login.php"); 
    //die("Redirecting to login.php");


//}
?>

[EDIT2] I get : Mail Sent. {"success":0,"message":"Database Error2. Please Try Again !"} The problem is in my query I guess? Arnaud

Answer 1

get JSONException: Value of type java.lang.String cannot be converted to JSONObject when parsing a JSON response

Likely that your web service is not returning correct JSON.

Answer 2

i wanted to put some comment but i should have at list 50 reputation!!! so i should give my answer here... i had same problem with json object. use "GET" method instead of "POST". try it...

USE THIS JSON PARSER

public class JSONParser extends Activity{

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 == "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 == "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) {
        Log.e("JSON PARSER", "GET OR POST");
        Toast.makeText(getApplicationContext(), "Something is wrong with network!", Toast.LENGTH_LONG).show();
        json="";
        create_JSon_Object();
    } catch (ClientProtocolException e) {
        Toast.makeText(getApplicationContext(), "Something is wrong with network!", Toast.LENGTH_LONG).show();
        Log.e("JSON PARSER", "GET OR POST");
        json="";
        return create_JSon_Object();
    } catch (IOException e) {
        Toast.makeText(getApplicationContext(), "Something is wrong with network!", Toast.LENGTH_LONG).show();
        Log.e("JSON PARSER IO ERROR", "GET OR POST");
        json="";
        return create_JSon_Object();
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is, "utf-8"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), "Something is wrong with network!", Toast.LENGTH_LONG).show();
        Log.e("JSON PARSER Buffer Error", "Error converting result ");
        json="";
        return create_JSon_Object();
    }
    return create_JSon_Object();

}

private JSONObject create_JSon_Object() {
    // try parse the string to a JSON object
    try {
        //jObj = new JSONObject(json);
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Toast.makeText(getApplicationContext(), "Something is wrong with network!", Toast.LENGTH_LONG).show();
        Log.e("JSON Parser", "Error parsing data " + e.toString());
        return jObj;
    }

    // return JSON String
    return jObj;
}
}

Answer 3

From server side, you need to send

{"success":0,"message":"Database Error2. Please Try Again !"}

instead of

Mail Sent. {"success":0,"message":"Database Error2. Please Try Again !"}