int a = 1;
a = a / 0;

-------------------------------------------
java.lang.ArithmeticException: / by zero

int a = 1;

try {
	a = a / 0;
}
catch( Exception e ) {
	System.out.println( e.getMessage() );
}

String a = null;
String b = new String(a);

-------------------------------------------
java.lang.NullPointerException

String a = null;
String b = null;

try {
	b = new String(a);
}
catch ( Exception e ) {
	b = "";
}