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PONull pointer Exception on Parsing URL in android
 

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  1. PONull pointer Exception on Parsing URL in android
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    <p>Here Im trying to parsing read from url and trying to print in console.Im using Asynctask as we cant have network connection on main thread</p> <pre><code>package com.example.parse; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.net.MalformedURLException; import java.net.URL; import android.os.AsyncTask; import android.os.Bundle; import android.app.Activity; import android.view.Menu; import android.view.View; import android.widget.Button; import android.widget.EditText; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final Button create =(Button) findViewById(R.id.button1); create.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { // Perform action on click EditText et1 = (EditText) findViewById(R.id.editText1); String url = et1.getText().toString(); new ParseString().execute(url); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } </code></pre> <p>}</p> <pre><code> class ParseString extends AsyncTask&lt;String, Void, BufferedReader&gt;{ @Override protected BufferedReader doInBackground(String... urls) { // TODO Auto-generated method stub BufferedReader in = null; URL url = null; try { url = new URL(urls[0]); } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { in = new BufferedReader( new InputStreamReader( url.openStream())); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return in; } protected void onPostExecute(BufferedReader buf){ String inputLine; try { while ((inputLine = buf.readLine()) != null) System.out.println(inputLine); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { buf.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } </code></pre> <p>This is the log cat error message</p> <pre><code>12-13 01:33:58.404: E/AndroidRuntime(1058): FATAL EXCEPTION: AsyncTask #2 12-13 01:33:58.404: E/AndroidRuntime(1058): Process: com.example.parse, PID: 1058 12-13 01:33:58.404: E/AndroidRuntime(1058): java.lang.RuntimeException: An error occured while executing doInBackground() 12-13 01:33:58.404: E/AndroidRuntime(1058): at android.os.AsyncTask$3.done(AsyncTask.java:300) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.FutureTask.setException(FutureTask.java:222) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.FutureTask.run(FutureTask.java:242) 12-13 01:33:58.404: E/AndroidRuntime(1058): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.lang.Thread.run(Thread.java:841) 12-13 01:33:58.404: E/AndroidRuntime(1058): Caused by: java.lang.NullPointerException 12-13 01:33:58.404: E/AndroidRuntime(1058): at com.example.parse.ParseString.doInBackground(MainActivity.java:62) 12-13 01:33:58.404: E/AndroidRuntime(1058): at com.example.parse.ParseString.doInBackground(MainActivity.java:1) 12-13 01:33:58.404: E/AndroidRuntime(1058): at android.os.AsyncTask$2.call(AsyncTask.java:288) 12-13 01:33:58.404: E/AndroidRuntime(1058): at java.util.concurrent.FutureTask.run(FutureTask.java:237) 12-13 01:33:58.404: E/AndroidRuntime(1058): ... 4 more </code></pre> <p>P.S I have added network permission in manifest.xml </p>
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    1. USAbhishek
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    1. COwhat is line 62 `MainActivity.java`?
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      1. PONull pointer Exception on Parsing URL in android
      1. USRaghunandan
    2. COwhen you `catch (MalformedURLException e)` you should immediately return null. Otherwise, you proceed and try to call url.openStream(), while url might be null due to previously ignored `MalformedURLException`
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    3. COurl.openStream()));
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