question: public static byte [ ] cloneByteArray ( byte [ ] b ) { if ( b == null ) { return null ; } int len = b . length ; if ( len == 0 ) { return EMPTY_BYTES ; } byte [ ] copy = new byte [ len ] ; System . arraycopy ( b , 0 , copy , 0 , len ) ; return copy ; }
target:  Create a new byte array and copy all the data. If the size of the byte array is zero, the same array is returned.