android中的byte數群組轉換

android中的byte數群組轉換

/** * 將一個單位元組的byte轉換成32位的int *  * @param b *            byte * @return convert result */public static int unsignedByteToInt(byte b) {return (int) b & 0xFF;}/** * 將一個單位元組的Byte轉換成十六進位的數 *  * @param b *            byte * @return convert result */public static String byteToHex(byte b) {int i = b & 0xFF;return Integer.toHexString(i);}/** * 將一個4byte的數群組轉換成32位的int *  * @param buf *            bytes buffer * @param byte[]中開始轉換的位置 * @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;}/** * 將16位的short轉換成byte數組 *  * @param s *            short * @return byte[] 長度為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;}/** * 將32位整數轉換成長度為4的byte數組 *  * @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轉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,無符號右移。return targets;}/** * 將長度為2的byte數群組轉換為16位int *  * @param res *            byte[] * @return int * */public static int byte2int(byte[] res) {// res = InversionByte(res);// 一個byte資料左移24位變成0x??000000，再右移8位變成0x00??0000int targets = (res[0] & 0xff) | ((res[1] << 8) & 0xff00); // | 表示安位或return targets;}/** * byte數組與short數群組轉換 *  * @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數組與short數群組轉換 *  * @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;}/** * 對象轉數組 *  * @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;}/** * 數組轉對象 *  * @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;}