CODEWITHSUNDEEP
androidhttp-posthttprequestgetjsonhttpexception
DroidLearner
DroidLearner

Reputation: 2135

NullPointerException on Simple HttpPost

If username & Password are correct it has to show "SUCCESS" else it has to show "FAILED".I'm connecting to a server using BasicNameValuePair. and its showing NullPointerException on this line int code = pres.getStatusLine().getStatusCode();

public class MyPostActivity extends Activity {
    DefaultHttpClient client;
    HttpPost post;
    HttpResponse res;
    HttpEntity ent;
    Button b;
    List<NameValuePair> pairs;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        b = (Button) findViewById(R.id.button1);
        client = new DefaultHttpClient();
        post = new HttpPost(
                "http://somesite.com/abc");
        b.setOnClickListener(new View.OnClickListener() {

            public void onClick(View v) {
                List<NameValuePair> pairs = new ArrayList<NameValuePair>(3);
                pairs.add(new BasicNameValuePair("Email", "avinash"));
                pairs.add(new BasicNameValuePair("password", "avinash2"));

                try {
                    post.setEntity(new UrlEncodedFormEntity(pairs));
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                HttpResponse pres = null;
                try {
                    pres = client.execute(post);
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                int code = pres.getStatusLine().getStatusCode();
                if (code == 200) {
                    Toast.makeText(getApplicationContext(), "Successful",
                            Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(getApplicationContext(), "Failed!",
                            Toast.LENGTH_SHORT).show();
                }
            }
        });

    }

}

enter image description here

Upvotes: 2

Views: 1069

Answers (3)

Nirali
Nirali

Reputation: 13805

Please add this permission also to your manifest and try

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" >
    </uses-permission>

And AsyncTask code 

private class SignInService extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        try {
            progressDilaog = ProgressDialog.show(MainActivity.this, "",
                    "Loading", true, false);

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

    @Override
    protected Void doInBackground(Void... params) {

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(url);

        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(5);
        nameValuePairs.add(new BasicNameValuePair("username", "abc"));
        nameValuePairs.add(new BasicNameValuePair("password", "bcd"));

        try {
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            try {
              HttpResponse response = httpclient.execute(httppost);

              int responsecode = response.getStatusLine().getStatusCode();


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

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        progressDilaog.dismiss();


    }
}

Upvotes: 1

Blackbelt
Blackbelt

Reputation: 157457

You should add the internet permission to the AndroidManifest.xml file. Also you should not perform blocking operations on the UI Thread. In fact the Http execute will cause the UI Thread to hang waiting for a response from the server. This will cause ANR (application not responding). I suggest you to read the following article

Upvotes: 4

Eran
Eran

Reputation: 393846

        try {
            pres = client.execute(post);
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        int code = pres.getStatusLine().getStatusCode();

Well the null pointer exception happens because you probably get an exception in your client.execute line and do noting about it (you just catch it). That's why pres is null. You should print the exception to find your real problem.

Upvotes: 0

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