android中的byte数组转换

/**
	 * 将一个单字节的byte转换成32位的int
	 * 
	 * @param b
	 *            byte
	 * @return convert result
	 */
	public static int unsignedByteToInt(byte b) {
		return (int) b & 0xFF;
	}

	/**
	 * 将一个单字节的Byte转换成十六进制的数
	 * 
	 * @param b
	 *            byte
	 * @return convert result
	 */
	public static String byteToHex(byte b) {
		int i = b & 0xFF;
		return Integer.toHexString(i);
	}

	/**
	 * 将一个4byte的数组转换成32位的int
	 * 
	 * @param buf
	 *            bytes buffer
	 * @param byte[]中开始转换的位置
	 * @return convert result
	 */
	public static long unsigned4BytesToInt(byte[] buf, int pos) {
		int firstByte = 0;
		int secondByte = 0;
		int thirdByte = 0;
		int fourthByte = 0;
		int index = pos;
		firstByte = (0x000000FF & ((int) buf[index]));
		secondByte = (0x000000FF & ((int) buf[index + 1]));
		thirdByte = (0x000000FF & ((int) buf[index + 2]));
		fourthByte = (0x000000FF & ((int) buf[index + 3]));
		index = index + 4;
		return ((long) (firstByte << 24 | secondByte << 16 | thirdByte << 8 | fourthByte)) & 0xFFFFFFFFL;
	}

	/**
	 * 将16位的short转换成byte数组
	 * 
	 * @param s
	 *            short
	 * @return byte[] 长度为2
	 * */
	public static byte[] shortToByteArray(short s) {
		byte[] targets = new byte[2];
		for (int i = 0; i < 2; i++) {
			int offset = (targets.length - 1 - i) * 8;
			targets[i] = (byte) ((s >>> offset) & 0xff);
		}
		return targets;
	}

	/**
	 * 将32位整数转换成长度为4的byte数组
	 * 
	 * @param s
	 *            int
	 * @return byte[]
	 * */
	public static byte[] intToByteArray(int s) {
		byte[] targets = new byte[2];
		for (int i = 0; i < 4; i++) {
			int offset = (targets.length - 1 - i) * 8;
			targets[i] = (byte) ((s >>> offset) & 0xff);
		}
		return targets;
	}

	/**
	 * long to byte[]
	 * 
	 * @param s
	 *            long
	 * @return byte[]
	 * */
	public static byte[] longToByteArray(long s) {
		byte[] targets = new byte[2];
		for (int i = 0; i < 8; i++) {
			int offset = (targets.length - 1 - i) * 8;
			targets[i] = (byte) ((s >>> offset) & 0xff);
		}
		return targets;
	}

	/** 32位int转byte[] */
	public static byte[] int2byte(int res) {
		byte[] targets = new byte[4];
		targets[0] = (byte) (res & 0xff);// 最低位
		targets[1] = (byte) ((res >> 8) & 0xff);// 次低位
		targets[2] = (byte) ((res >> 16) & 0xff);// 次高位
		targets[3] = (byte) (res >>> 24);// 最高位,无符号右移。
		return targets;
	}

	/**
	 * 将长度为2的byte数组转换为16位int
	 * 
	 * @param res
	 *            byte[]
	 * @return int
	 * */
	public static int byte2int(byte[] res) {
		// res = InversionByte(res);
		// 一个byte数据左移24位变成0x??000000，再右移8位变成0x00??0000
		int targets = (res[0] & 0xff) | ((res[1] << 8) & 0xff00); // | 表示安位或
		return targets;
	}

	/**
	 * byte数组与short数组转换
	 * 
	 * @param data
	 * @param items
	 * @return
	 */
	public static short[] byteArray2ShortArray(byte[] data) {
		if (data == null) {
			// Log.e(TAG, "byteArray2ShortArray, data = null");
			return null;
		}

		short[] retVal = new short[data.length / 2];
		for (int i = 0; i < retVal.length; i++) {
			retVal[i] = (short) ((data[i * 2] & 0xff) | (data[i * 2 + 1] & 0xff) << 8);
		}

		return retVal;
	}

	/**
	 * byte数组与short数组转换
	 * 
	 * @param data
	 * @param items
	 * @return
	 */
	public static byte[] shortArray2ByteArray(short[] data) {
		byte[] retVal = new byte[data.length * 2];
		for (int i = 0; i < retVal.length; i++) {
			int mod = i % 2;
			if (mod == 0) {
				retVal[i] = (byte) (data[i / 2]);
			} else {
				retVal[i] = (byte) (data[i / 2] >> 8);
			}
		}

		return retVal;
	}

	/**
	 * 对象转数组
	 * 
	 * @param obj
	 * @return
	 */
	public static byte[] toByteArray(Object obj) {
		byte[] bytes = null;
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		try {
			ObjectOutputStream oos = new ObjectOutputStream(bos);
			oos.writeObject(obj);
			oos.flush();
			bytes = bos.toByteArray();
			oos.close();
			bos.close();
		} catch (IOException ex) {
			ex.printStackTrace();
		}
		return bytes;
	}

	/**
	 * 数组转对象
	 * 
	 * @param bytes
	 * @return
	 */
	public static Object toObject(byte[] bytes) {
		Object obj = null;
		try {
			ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
			ObjectInputStream ois = new ObjectInputStream(bis);
			obj = ois.readObject();
			ois.close();
			bis.close();
		} catch (IOException ex) {
			ex.printStackTrace();
		} catch (ClassNotFoundException ex) {
			ex.printStackTrace();
		}
		return obj;
	}