crypto/src/main/java/org/springframework/security/crypto/util/EncodingUtils.java
public static byte[] subArray(byte[] array, int beginIndex, int endIndex) {
		int length = endIndex - beginIndex;
		byte[] subarray = new byte[length];
		System.arraycopy(array, beginIndex, subarray, 0, length);
		return subarray;
	}
public static byte[] subArray(byte[] array, int beginIndex, int endIndex) {
		int length = endIndex - beginIndex;
		byte[] subarray = new byte[length];
		System.arraycopy(array, beginIndex, subarray, 0, length);
		return subarray;
	}
Extract a sub array of bytes out of the byte array.
@param array the byte array to extract from
@param beginIndex the beginning index of the sub array, inclusive
@param endIndex the ending index of the sub array, exclusive