Throwing multiple exceptions Java
Throws multiple exceptions Java example source code
public void callFc()
throws IndexOutOfBoundsException, ArithmeticException
{
// my code for example:
String[] sArray = {"aa","bb"};
String str = sArray[5]; // IndexOutOfBoundsException
int n = 5 / 0; // ArithmeticException
}
public void someFC (){
try{
callFc();
}
catch(IndexOutOfBoundsException e){
Log.e("TAG", e.toString());
}
catch(ArithmeticException e2){
Log.e2("TAG",e2.toString());
}
}
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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
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.
Diagram of life cycle onSaveInstanceState, onRestoreInstanceState
[caption id="attachment_1169" align="alignleft" width="229" caption="Life cycle onRestoreInstanceState"]
[/caption]
// 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"]

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
main.xml
strings.xml
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>
Editace: 2013-12-09 10:15:41
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Url:throwing-multiple-exceptions-java