如何将JSON数据从Android发送到php url？

Question

i want to send login infromation from my App to php url.as this my App will crash.can any one help me to slove this.

this my server login method. i want to send data to this login method..

   Method [  public method login ] {

      - Parameters [3] {
        Parameter #0 [  $user_auth ]
        Parameter #1 [  $application ]
        Parameter #2 [  $name_value_list = Array ]
      }
    }

this is my login.java in android app

public class Login extends ActionBarActivity implements View.OnClickListener {

    EditText userName, pass;
    Button login;

    private ProgressDialog pDialog;

    JSONParser jsonParser = new JSONParser();

    private static final String LOGIN_URL = "http://crm.demo.com/service/v4_1/rest.php/login";

    private static final String TAG_SUCCESS = "sucess";
    private static final String TAG_MESSAGE = "message";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        userName = (EditText) findViewById(R.id.editText_userN);
        pass = (EditText) findViewById(R.id.editText_pass);
        login = (Button) findViewById(R.id.btn_login);

        login.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        Log.d("v", "Login button clicked");

        new AttemptLogin().execute();
    }

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

        @Override
        protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(Login.this);
        pDialog.setMessage("Attempting login..");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
        pDialog.dismiss();
        }

        @Override
        protected String doInBackground(String... args) {

             // Check for success tag
            int success;
            String user_auth[];
            String user_name = userName.getText().toString();
            String password = pass.getText().toString();
            String application = "wakensys";
            String name_value_list[];
            String language = "en-au";
            String notifyonsave = "true";

            try {
                // Building Parameters
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("user_auth[]", user_name));
                params.add(new BasicNameValuePair("user_auth[]", password));
                params.add(new BasicNameValuePair("application", application));
                params.add(new BasicNameValuePair("name_value_list[]", language));
                params.add(new BasicNameValuePair("name_value_list[]", notifyonsave));


                Log.d("request!", "starting..");
                Log.i("NameValuePair", params.toString());
                // getting product details by making HTTP request
                JSONObject json = jsonParser.makeHttpRequest(LOGIN_URL, "POST", params);
                if(json == null)
                    return null;

                // check your log for json response
                Log.d("Login attempt", json.toString());

                // json success tag
                success = json.getInt(TAG_SUCCESS);
                if (success == 1) {
                    Log.d("Login Successful!", json.toString());
                    Intent i = new Intent(Login.this, Success.class);
                    finish();
                    startActivity(i);
                    return json.getString(TAG_MESSAGE);
                }else{
                    Log.d("Login Failure!", json.getString(TAG_MESSAGE));
                    return json.getString(TAG_MESSAGE);

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }
        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // dismiss the dialog once product deleted
            pDialog.dismiss();
            if (file_url != null){
                Toast.makeText(Login.this, file_url, Toast.LENGTH_LONG).show();
            }
        }
    }
}

--new logcat---

11-21 10:33:34.467: D/v(4400): Login button clicked
11-21 10:33:34.496: D/request!(4400): starting..
11-21 10:33:34.496: I/NameValuePair(4400): [user_auth=dghj, user_auth=ccbj, name_value_list=EN]
11-21 10:33:36.528: E/JSON Parser(4400): Error parsing data org.json.JSONException: Value <pre> of type java.lang.String cannot be converted to JSONObject
11-21 10:33:36.531: E/AndroidRuntime(4400): FATAL EXCEPTION: AsyncTask #1
11-21 10:33:36.531: E/AndroidRuntime(4400): Process: com.wakensys.sugercrm, PID: 4400
11-21 10:33:36.531: E/AndroidRuntime(4400): java.lang.RuntimeException: An error occured while executing doInBackground()
11-21 10:33:36.531: E/AndroidRuntime(4400):     at android.os.AsyncTask$3.done(AsyncTask.java:300)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.FutureTask.run(FutureTask.java:242)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.lang.Thread.run(Thread.java:818)
11-21 10:33:36.531: E/AndroidRuntime(4400): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String org.json.JSONObject.toString()' on a null object reference
11-21 10:33:36.531: E/AndroidRuntime(4400):     at com.wakensys.sugercrm.Login$AttemptLogin.doInBackground(Login.java:116)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at com.wakensys.sugercrm.Login$AttemptLogin.doInBackground(Login.java:1)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at android.os.AsyncTask$2.call(AsyncTask.java:288)
11-21 10:33:36.531: E/AndroidRuntime(4400):     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
11-21 10:33:36.531: E/AndroidRuntime(4400):     ... 4 more

Any Help Please !!

JOSONparser.java

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 + "
");
            }

            // 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 + "
");
            }
            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;

    }
}

Answer 1

You can try your code like this, works perfect for me.

public class Login extends ActionBarActivity
{
    EditText tv, tv2;
    String email;
    int a;
    String password;

    JSONParser jsonParser = new JSONParser();

    private ProgressDialog dialog;

    private static String register_user = "your link here";

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
          super.onCreate(savedInstanceState);

          setContentView(R.layout.activity_login);

          tv = (EditText) findViewById(R.id.editText1);
          tv2 = (EditText) findViewById(R.id.editText2);
    }

    public void Login(View view)
    {
          email = tv.getText().toString().trim();
          password = tv2.getText().toString();

          if(TextUtils.isEmpty(email) || TextUtils.isEmpty(password))
          {
                if(TextUtils.isEmpty(email))
                {
                    tv.setError("This field cannot be empty");
                }
                if(TextUtils.isEmpty(password))
                {
                    tv2.setError("This field cannot be empty");
                }
            }
            else
            {
                //build Params
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("email", email));
                params.add(new BasicNameValuePair("password", password));

                CreateNewProduct productTask = new CreateNewProduct(params);
                productTask.execute();
            }
    }

    class CreateNewProduct extends AsyncTask<String, String, JSONObject>
    {
         List<NameValuePair> params;

         public CreateNewProduct(List<NameValuePair> params)
        {
             this.params = params;
        }

        protected void onPreExecute()
        {
            super.onPreExecute();
            dialog = new ProgressDialog(Login.this);
            dialog.setMessage("We are Logging in. Please wait . . .");
            dialog.setIndeterminate(false);
            dialog.setCancelable(false);
            dialog.show();
        }

        protected JSONObject doInBackground(String... args)
        {
             JSONObject json = jsonParser.makeHttpRequest(register_user, "POST", this.params);

             return json;
        }

        protected void onPostExecute(JSONObject result)
        {
               dialog.dismiss();
              //this assumes that the response looks like this:
              //{"success" : true }
              String message = null;
              try {
                  message = result.getString("message");
              } catch (JSONException e1) {
                  // TODO Auto-generated catch block
                  e1.printStackTrace();
              }
              boolean success = false;
              try {
                success = result.getBoolean("success");
              } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
              }
              Toast.makeText(getBaseContext(), success ? "We are good to go." : "Something went wrong!", 
              Toast.LENGTH_SHORT).show();
              Toast.makeText(getBaseContext(), message, Toast.LENGTH_LONG).show();
        }
    }
}

Now according to your success value, you can take certain actions. You can also try other combinations of JSON outputs from your php script.