JAVA - How convert decimal to binary, hex, octal etc.

For converting from decimal to binary, hexadecimal, octal etc., use function Integer.toString().
Second parameter is base.

String sText = "";
Integer iValue;
String sValue = "";

/* -- convert from dec */

sValue = Integer.toString( 100, 10 );
sText += "dec(100) to dec =" + sValue + "\n";

sValue = Integer.toString( 100, 2 );
sText += "dec(100) to bin =" + sValue + "\n";

sValue = Integer.toString( 100, 16 );
sText += "dec(100) to hex =" + sValue + "\n";

sValue = Integer.toString( 255, 16 );
sText += "dec(255) to hex =" + sValue + "\n";

/* result */

memo.setText( sText );      

Output: