Throwing multiple exceptions Java

Codec, compress(), CompressFormat, quality, decodeByteArray(), Android example source code with image.

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static Bitmap codec(Bitmap src, Bitmap.CompressFormat format,
			int quality) {
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		src.compress(format, quality, os);

		byte[] array = os.toByteArray();
		return BitmapFactory.decodeByteArray(array, 0, array.length);
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GRAY);
            
                        //  you need to insert some image flower_blue into res/drawable folder
			Bitmap b = BitmapFactory.decodeResource(getResources(), R.drawable.flower_blue);
                        // Best of quality is 80 and more, 3 is very low quality of image 
			Bitmap bJPGcompress = codec(b, Bitmap.CompressFormat.JPEG, 3);
                   // get dimension of bitmap getHeight()  getWidth()
		   int h = b.getHeight();
           
           canvas.drawBitmap(b, 10,10, paint);
           canvas.drawBitmap(bJPGcompress, 10,10 + h + 10, paint);
           
		}

	}
}

Difference between "@+id/” and "@id/” in Android
android:id="@+id/xxx" unique identifier of view
@id/ a reference to the unique identifier

 <TextView
        android:id="@+id/first_element_id"
        .........
 />
    <TextView
        android:id="@+id/second_element_id"
        android:layout_below="@id/first_element_id"
        ..........
 />

onSaveInstanceState, onRestoreInstanceState life cycle if screen orientation changed from log file.

// starts activity
15:27:12.801: INFO/onCreate(1828): onCreate()
15:27:12.811: INFO/onStart(1828): onStart()
15:27:12.821: INFO/onResume(1828): onResume()
// activity is running 

15:27:33.651: DEBUG/dalvikvm(307): GC_EXPLICIT freed 186K, 53% 
free 2770K/5831K, external 981K/1038K, paused 99ms

// change emulator state Ctrl+F11 landscape, portrait
15:27:40.427: INFO/ActivityManager(74): Config changed: 
{ scale=1.0 imsi=310/260 loc=en_US touch=3 keys=2/1/2 nav=3/1 orien=2 layout=18 uiMode=17 seq=64}

// saved all variable values if need
15:27:40.581: INFO/onSaveInstanceState(1828): onSaveInstanceState()

15:27:40.602: INFO/onPause(1828): onPause()
15:27:40.612: INFO/onStop(1828): onStop()
15:27:40.631: INFO/onDestroy(1828): onDestroy()

// activity goes back to onCreate !!!!!!!!!
15:27:40.692: INFO/onCreate(1828): onCreate()
15:27:40.701: INFO/onStart(1828): onStart()

// restore all saved values of variables 
15:27:40.711: INFO/onRestoreInstanceState(1828): onRestoreInstanceState()
// you can using saved values by onSaveInstanceState() in onResume
15:27:40.721: INFO/onResume(1828): onResume()

Diagram of life cycle onSaveInstanceState, onRestoreInstanceState

[caption id="attachment_1169" align="alignleft" width="229" caption="Life cycle onRestoreInstanceState"][/caption]

Convert number int to string Android Java example source code.

int n = 0;

try {
    n = Integer.parseInt("21"));
} catch(NumberFormatException e) {
   System.out.println("Could not parse " + e);
} 
// int to string
String s = String.valueOf(24);

Change table row background color if user click on row Android example code.
MainActivity.java

public class MainActivity extends Activity {
Boolean bColorYellow = true;
TextView hTextView;
TableRow hTableRow;
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        hTextView = (TextView)findViewById(R.id.idTextView);
        hTableRow = (TableRow)findViewById(R.id.idTableRow1);


        
        
    } // end onCreate
  
    
    public void myTableRowClickHandler(View view) {
		switch (view.getId()) {
		case R.id.idTableRow1:{
			
			if(bColorYellow){
			hTableRow.setBackgroundColor(Color.GREEN);
			bColorYellow = false;
			}
			else{
			hTableRow.setBackgroundColor(Color.YELLOW);
			bColorYellow = true;
			}
		}
		break;
		}
  }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >


<TableLayout android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/tableLayout1">
    <TableRow android:id="@+id/idTableRow1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:background="#5655AA"
    android:onClick="@string/myTableRowClick"
    android:focusable="true">
<TextView  
	android:id="@+id/idTextView"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
    
    </TableRow>
</TableLayout>
    
    
</LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World!</string>
    <string name="app_name">TableRow</string>
    <string name="myTableRowClick">myTableRowClickHandler</string>
</resources>