com.zx.sms.common.util.ByteArrayUtil Maven / Gradle / Ivy
package com.zx.sms.common.util;
/*
* #%L
* ch-commons-util
* %%
* Copyright (C) 2012 Cloudhopper by Twitter
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
/**
* Utility class for working with byte arrays such as converting between
* byte arrays and numbers.
*
* @author joelauer (twitter: @jjlauer or http://twitter.com/jjlauer)
*/
public class ByteArrayUtil {
protected static void checkBytesNotNull(byte[] bytes) {
if (bytes == null) {
throw new IllegalArgumentException("Byte array was null");
}
}
/**
* Helper method for validating if an offset and length are valid for a given
* byte array. Checks if the offset or length is negative or if the offset+length
* would cause a read past the end of the byte array.
* @param bytesLength The length of the byte array to validate against
* @param offset The offset within the byte array
* @param length The length to read starting from the offset
* @throws java.lang.IllegalArgumentException If any of the above conditions
* are violated.
*/
static protected void checkOffsetLength(int bytesLength, int offset, int length)
throws IllegalArgumentException {
// offset cannot be negative
if (offset < 0) {
throw new IllegalArgumentException("The byte[] offset parameter cannot be negative");
}
// length cannot be negative either
if (length < 0) {
throw new IllegalArgumentException("The byte[] length parameter cannot be negative");
}
// is it a valid offset? Must be < bytes.length if non-zero
// if its zero, then the check below will validate if it would cause
// a read past the length of the byte array
if (offset != 0 && offset >= bytesLength) {
throw new IllegalArgumentException("The byte[] offset (" + offset + ") must be < the length of the byte[] length (" + bytesLength + ")");
}
if (offset+length > bytesLength) {
throw new IllegalArgumentException("The offset+length (" + (offset+length) + ") would read past the end of the byte[] (length=" + bytesLength + ")");
}
}
protected static void checkBytes(byte[] bytes, int offset, int length, int expectedLength) {
checkBytesNotNull(bytes);
checkOffsetLength(bytes.length, offset, length);
if (length != expectedLength) {
throw new IllegalArgumentException("Unexpected length of byte array [expected=" + expectedLength + ", actual=" + length + "]");
}
}
public static byte[] toByteArray(byte value) {
return new byte[] { value };
}
public static byte[] toByteArray(short value) {
byte[] buf = new byte[2];
buf[1] = (byte)(value & 0xFF);
buf[0] = (byte)((value >>> 8) & 0xFF);
return buf;
}
public static byte[] toByteArray(int value) {
byte[] buf = new byte[4];
buf[3] = (byte)(value & 0xFF);
buf[2] = (byte)((value >>> 8) & 0xFF);
buf[1] = (byte)((value >>> 16) & 0xFF);
buf[0] = (byte)((value >>> 24) & 0xFF);
return buf;
}
public static byte[] toByteArray(long value) {
byte[] buf = new byte[8];
buf[7] = (byte)(value & 0xFF);
buf[6] = (byte)((value >>> 8) & 0xFF);
buf[5] = (byte)((value >>> 16) & 0xFF);
buf[4] = (byte)((value >>> 24) & 0xFF);
buf[3] = (byte)((value >>> 32) & 0xFF);
buf[2] = (byte)((value >>> 40) & 0xFF);
buf[1] = (byte)((value >>> 48) & 0xFF);
buf[0] = (byte)((value >>> 56) & 0xFF);
return buf;
}
public static byte toByte(byte[] bytes) {
checkBytesNotNull(bytes);
return toByte(bytes, 0, bytes.length);
}
public static byte toByte(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 1);
return bytes[offset];
}
public static short toUnsignedByte(byte[] bytes) {
checkBytesNotNull(bytes);
return toUnsignedByte(bytes, 0, bytes.length);
}
public static short toUnsignedByte(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 1);
short v = 0;
v |= bytes[offset] & 0xFF;
return v;
}
public static short toShort(byte[] bytes) {
checkBytesNotNull(bytes);
return toShort(bytes, 0, bytes.length);
}
public static short toShort(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 2);
short v = 0;
v |= bytes[offset] & 0xFF;
v <<= 8;
v |= bytes[offset+1] & 0xFF;
return v;
}
public static int toUnsignedShort(byte[] bytes) {
checkBytesNotNull(bytes);
return toUnsignedShort(bytes, 0, bytes.length);
}
public static int toUnsignedShort(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 2);
int v = 0;
v |= bytes[offset] & 0xFF;
v <<= 8;
v |= bytes[offset+1] & 0xFF;
return v;
}
public static int toInt(byte[] bytes) {
checkBytesNotNull(bytes);
return toInt(bytes, 0, bytes.length);
}
public static int toInt(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 4);
int v = 0;
v |= bytes[offset] & 0xFF;
v <<= 8;
v |= bytes[offset+1] & 0xFF;
v <<= 8;
v |= bytes[offset+2] & 0xFF;
v <<= 8;
v |= bytes[offset+3] & 0xFF;
return v;
}
public static long toUnsignedInt(byte[] bytes) {
checkBytesNotNull(bytes);
return toUnsignedInt(bytes, 0, bytes.length);
}
public static long toUnsignedInt(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 4);
long v = 0;
v |= bytes[offset] & 0xFF;
v <<= 8;
v |= bytes[offset+1] & 0xFF;
v <<= 8;
v |= bytes[offset+2] & 0xFF;
v <<= 8;
v |= bytes[offset+3] & 0xFF;
return v;
}
public static long toLong(byte[] bytes) {
checkBytesNotNull(bytes);
return toLong(bytes, 0, bytes.length);
}
public static long toLong(byte[] bytes, int offset, int length) {
checkBytes(bytes, offset, length, 8);
long v = 0;
v |= bytes[offset] & 0xFF;
v <<= 8;
v |= bytes[offset+1] & 0xFF;
v <<= 8;
v |= bytes[offset+2] & 0xFF;
v <<= 8;
v |= bytes[offset+3] & 0xFF;
v <<= 8;
v |= bytes[offset+4] & 0xFF;
v <<= 8;
v |= bytes[offset+5] & 0xFF;
v <<= 8;
v |= bytes[offset+6] & 0xFF;
v <<= 8;
v |= bytes[offset+7] & 0xFF;
return v;
}
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