Pixel to density independent pixel to pixel conversion

package com.asynctaskexample;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends Activity {
	private TextView textView;
	private ProgressBar progressBar;
	private DownloadWebPageTask mTask = null;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		textView = (TextView) findViewById(R.id.TextView01);
		downloadPage();
	}

	// AsyncTask <TypeOfVarArgParams , ProgressValue , ResultValue> .
	private class DownloadWebPageTask extends AsyncTask<String, Integer, String> {

		@Override
		protected void onPreExecute() {
			//textView.setText("Hello !!!");
			progressBar = (ProgressBar) findViewById(R.id.progressBar1);
			progressBar.setVisibility(View.VISIBLE);
			super.onPreExecute();
		}

		@Override
		protected void onProgressUpdate(Integer... values) {
			super.onProgressUpdate(values);

		}

		@Override
		protected String doInBackground(String... urls) {
			String response = "";
			for (String url : urls) {
				DefaultHttpClient client = new DefaultHttpClient();
				HttpGet httpGet = new HttpGet(url);
				try {
					HttpResponse execute = client.execute(httpGet);
					InputStream content = execute.getEntity().getContent();

					BufferedReader buffer = new BufferedReader(new InputStreamReader(
							content));
					String s = "";
					while ((s = buffer.readLine()) != null) {
						response += s;
					}

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

		@Override
		protected void onPostExecute(String result) {
			progressBar.setVisibility(View.INVISIBLE);
			textView.setText(result);
		}
	}

	private void downloadPage() {
		if (mTask != null
				&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
			mTask.cancel(true);
		}
               // execute(String[]) you can put array of links to web pages, or array of Integer[] 
               // if first param is Integer[] etc.
		mTask = (DownloadWebPageTask) new DownloadWebPageTask()
				.execute(new String[] { "//android.okhelp.cz/android-market.html",
						"//android.okhelp.cz/android-market.html" });
	}

	@Override
	protected void onDestroy() {
		super.onDestroy();

		if (mTask != null
				&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
			mTask.cancel(true);
			mTask = null;
		}
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.activity_main, menu);
		return true;
	}

}

<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ProgressBar
        android:id="@+id/progressBar1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/TextView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</LinearLayout>

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

Context context = getApplicationContext();
String DB_PATH = "/data/data/"
                + context.getPackageName()
                + "/databases/";

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        final AssetManager assetManager = getAssets();
        try {
			// for assets folder add empty string
                        String[] filelist = assetManager.list("");
                        // for assets/subFolderInAssets add only subfolder name
                        String[] filelistInSubfolder = assetManager.list("subFolderInAssets");
			if (filelist == null) {
			    // dir does not exist or is not a directory
			} else {
			    for (int i=0; i<filelist.length; i++) {
			        // Get filename of file or directory
			        String filename = filelist[i];
			    }
			}
                     
                        // if(filelistInSubfolder == null) ............  

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

      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (ArrayIndexOutOfBoundsException e) {
      		String s = e.toString(); // s == java.lang.ArrayIndexOutOfBoundsException
                // try to testing String s for null value
      		if(s != null)
      		 Log.e("bla", s);
      		else 
      		 Log.e("bla", "My error text 1");
      		
      		String s2 = e.getMessage(); // s2 == null !!!!!!!
                // you need to testing String s2 for null value , or you get FATAL EXCEPTION: main
                // and application will be crashed
       		String s2 = e.getMessage(); // s2 == null !!!!!!!
      		if(s2 != null)
      		 Log.e("bla2", e.getMessage());
      		else 
      		 Log.e("bla2", "My error text 2");
     		
                // this is OK
      		e.printStackTrace();
      	}

E/bla(855): java.lang.ArrayIndexOutOfBoundsException

 E/bla2(855): My error text 2

 W/System.err(855): java.lang.ArrayIndexOutOfBoundsException
 W/System.err(855): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
 W/System.err(855): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
 W/System.err(855): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
 W/System.err(855): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
 W/System.err(855): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
 W/System.err(855): 	at android.os.Handler.dispatchMessage(Handler.java:99)
 W/System.err(855): 	at android.os.Looper.loop(Looper.java:123)
 W/System.err(855): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
 W/System.err(855): 	at java.lang.reflect.Method.invokeNative(Native Method)
 W/System.err(855): 	at java.lang.reflect.Method.invoke(Method.java:507)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
 W/System.err(855): 	at dalvik.system.NativeStart.main(Native Method)

      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (Exception e) {
      		
      		
      		StringBuilder sb = new  StringBuilder().append(e.getClass().getSimpleName()); 
          if  (e.getMessage() != null) { 
              sb.append("

"); 
              sb.append(e.getMessage()); 
          } 
          Log.e("err", sb.toString()); // E/err(336): ArrayIndexOutOfBoundsException

          // this code write out all message
          Log.e("myError", "methodName", e);
       }
// E/myError(371): methodName
// E/myError(371): java.lang.ArrayIndexOutOfBoundsException
// E/myError(371): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
// E/myError(371): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
// E/myError(371): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
// E/myError(371): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
// E/myError(371): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
// E/myError(371): 	at android.os.Handler.dispatchMessage(Handler.java:99)
// E/myError(371): 	at android.os.Looper.loop(Looper.java:123)
// E/myError(371): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
// E/myError(371): 	at java.lang.reflect.Method.invokeNative(Native Method)
// E/myError(371): 	at java.lang.reflect.Method.invoke(Method.java:507)
// E/myError(371): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
// E/myError(371): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
// E/myError(371): 	at dalvik.system.NativeStart.main(Native Method)