clear n bits in a binary number from both sides

clearBitsIthrough0.java

public static int clearBitsIthrough0(int num,int i){
	System.out.println("clearing bits "+i+" to 0 of number:"+Integer.toBinaryString(num));
	int mask  = ~(0<<31);  // mask with all bits set
	mask = mask<<i+1;      // mask with bits 0 to i cleared
	System.out.println("using mask:"+Integer.toBinaryString(mask));
	return num & mask;
}

clearBitsMSBthroughI.java

public static int clearBitsMSBthroughI(int num,int i){
	System.out.println("clearing bits MSB to "+i+" of number:"+Integer.toBinaryString(num));
	int mask = (~(0<<32-(i+1)))<<i;  //mask with only last i bits set
	mask = ~mask;                    //complement to get the required mask
	System.out.println("using mask:"+Integer.toBinaryString(mask));
	return num & mask;
}