java基本類型與byte字節數組的轉換（包含大端，小端）

　　　　近期java項目中需要解析來自c/c++的字節數據，但是解析的過程中涉及到了字節數組數據大端、小端排序的問題，所以整理補充了基本類型short、int、long與byte數組以分別大端和小端相互轉換的方法。

 /**
     * 將int轉為高字節在前，低字節在后的byte數組（大端）
     * @param n int
     * @return byte[]
     */
    public static byte[] intToByteBig(int n) {
        byte[] b = new byte[4];
        b[3] = (byte) (n & 0xff);
        b[2] = (byte) (n >> 8 & 0xff);
        b[1] = (byte) (n >> 16 & 0xff);
        b[0] = (byte) (n >> 24 & 0xff);
        return b;
    }
 /**
  * 將int轉為低字節在前，高字節在后的byte數組（小端）
  * @param n int
  * @return byte[]
  */
    public static byte[] intToByteLittle(int n) {
        byte[] b = new byte[4];
        b[0] = (byte) (n & 0xff);
        b[1] = (byte) (n >> 8 & 0xff);
        b[2] = (byte) (n >> 16 & 0xff);
        b[3] = (byte) (n >> 24 & 0xff);
        return b;
    }
    /**
     * byte數組到int的轉換(小端)
     * @param bytes
     * @return
     */
    public static int bytes2IntLittle(byte[] bytes )
    {
        int int1=bytes[0]&0xff;
        int int2=(bytes[1]&0xff)<<8;
        int int3=(bytes[2]&0xff)<<16;
        int int4=(bytes[3]&0xff)<<24;

        return int1|int2|int3|int4;
    }
    /**
     * byte數組到int的轉換(大端)
     * @param bytes
     * @return
     */
    public static int bytes2IntBig(byte[] bytes )
    {
        int int1=bytes[3]&0xff;
        int int2=(bytes[2]&0xff)<<8;
        int int3=(bytes[1]&0xff)<<16;
        int int4=(bytes[0]&0xff)<<24;

        return int1|int2|int3|int4;
    }
    /**
     * 將short轉為高字節在前，低字節在后的byte數組（大端）
     * @param n short
     * @return byte[]
     */
    public static byte[] shortToByteBig(short n) {
        byte[] b = new byte[2];
        b[1] = (byte) (n & 0xff);
        b[0] = (byte) (n >> 8 & 0xff);
        return b;
    }

    /**
     * 將short轉為低字節在前，高字節在后的byte數組(小端)
     * @param n short
     * @return byte[]
     */
    public static byte[] shortToByteLittle(short n) {
        byte[] b = new byte[2];
        b[0] = (byte) (n & 0xff);
        b[1] = (byte) (n >> 8 & 0xff);
        return b;
    }
    /**
     *  讀取小端byte數組為short
     * @param b
     * @return
     */
    public static short byteToShortLittle(byte[] b) {
        return (short) (((b[1] << 8) | b[0] & 0xff));
    }
    /**
     *  讀取大端byte數組為short
     * @param b
     * @return
     */
    public static short byteToShortBig(byte[] b) {
        return (short) (((b[0] << 8) | b[1] & 0xff));
    }
    /**
     * long類型轉byte[] (大端)
     * @param n
     * @return
     */
    public static byte[] longToBytesBig(long n) {
        byte[] b = new byte[8];
        b[7] = (byte) (n & 0xff);
        b[6] = (byte) (n >> 8  & 0xff);
        b[5] = (byte) (n >> 16 & 0xff);
        b[4] = (byte) (n >> 24 & 0xff);
        b[3] = (byte) (n >> 32 & 0xff);
        b[2] = (byte) (n >> 40 & 0xff);
        b[1] = (byte) (n >> 48 & 0xff);
        b[0] = (byte) (n >> 56 & 0xff);
        return b;
    }
    /**
     * long類型轉byte[] (小端)
     * @param n
     * @return
     */
    public static byte[] longToBytesLittle(long n) {
        byte[] b = new byte[8];
        b[0] = (byte) (n & 0xff);
        b[1] = (byte) (n >> 8  & 0xff);
        b[2] = (byte) (n >> 16 & 0xff);
        b[3] = (byte) (n >> 24 & 0xff);
        b[4] = (byte) (n >> 32 & 0xff);
        b[5] = (byte) (n >> 40 & 0xff);
        b[6] = (byte) (n >> 48 & 0xff);
        b[7] = (byte) (n >> 56 & 0xff);
        return b;
    }
       /**
     * byte[]轉long類型(小端)
     * @param array
     * @return
     */
    public static long bytesToLongLittle( byte[] array )
    {
        return ((((long) array[ 0] & 0xff) << 0)
                | (((long) array[ 1] & 0xff) << 8)
                | (((long) array[ 2] & 0xff) << 16)
                | (((long) array[ 3] & 0xff) << 24)
                | (((long) array[ 4] & 0xff) << 32)
                | (((long) array[ 5] & 0xff) << 40)
                | (((long) array[ 6] & 0xff) << 48)
                | (((long) array[ 7] & 0xff) << 56));
    }

    /**
     * byte[]轉long類型(大端)
     * @param array
     * @return
     */
    public static long bytesToLongBig( byte[] array )
    {
        return ((((long) array[ 0] & 0xff) << 56)
                | (((long) array[ 1] & 0xff) << 48)
                | (((long) array[ 2] & 0xff) << 40)
                | (((long) array[ 3] & 0xff) << 32)
                | (((long) array[ 4] & 0xff) << 24)
                | (((long) array[ 5] & 0xff) << 16)
                | (((long) array[ 6] & 0xff) << 8)
                | (((long) array[ 7] & 0xff) << 0));
    }