Buffer an Unsigned Integer in Java

Question

I am trying to add an unsigned integer in Java, I know they are not supported, but I feel they would help in our case and make it easier than a long.

I would like to make an int of getUInt(), etc.

Our current code:

//--- functions ---
public int unsigned(int index){
    byte b = buf[index];
    if (b>=0) return b;
    return 256 + b;
}

public void setInt(int index,int val){
    buf[index+0] = (byte)(val&0xff);
    buf[index+1] = (byte)((val>>8)&0xff);
    buf[index+2] = (byte)((val>>16)&0xff);
    buf[index+3] = (byte)((val>>24)&0xff);
}
public void setShort(int index,int val){
    buf[index+0] = (byte)(val&0xff);
    buf[index+1] = (byte)((val>>8)&0xff);
}

public int getInt(int index){
    return (buf[index+3]<<24) | (unsigned(index+2)<<16) | (unsigned(index+1)<<8) | unsigned(index+0);
}   
public int getShort(int index){
    return (buf[index+1]<<8) | unsigned(index+0);
}
public int getUShort(int index){
    return (unsigned(index+1)<<8) | unsigned(index+0);
}

How would I go about doing so, every time I get into the wrong buffer and get zeros.

Thanks for all your help, -Michael