各数据类型转换byte数组(方便java和c++的网络通信)

package platformlink;

public class ByteConvert {
    // 以下 是整型数 和 网络字节序的  byte[] 数组之间的转换
    public static byte[] longToBytes(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;
    }
   
    public static void longToBytes( long n, byte[] array, int offset ){
        array[7+offset] = (byte) (n & 0xff);
        array[6+offset] = (byte) (n >> 8 & 0xff);
        array[5+offset] = (byte) (n >> 16 & 0xff);
        array[4+offset] = (byte) (n >> 24 & 0xff);
        array[3+offset] = (byte) (n >> 32 & 0xff);
        array[2+offset] = (byte) (n >> 40 & 0xff);
        array[1+offset] = (byte) (n >> 48 & 0xff);
        array[0+offset] = (byte) (n >> 56 & 0xff);
    }
   
    public static long bytesToLong( 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));       
    }
   
    public static long bytesToLong( byte[] array, int offset )
    {
        return ((((long) array[offset + 0] & 0xff) << 56)
              | (((long) array[offset + 1] & 0xff) << 48)
              | (((long) array[offset + 2] & 0xff) << 40)
              | (((long) array[offset + 3] & 0xff) << 32)
              | (((long) array[offset + 4] & 0xff) << 24)
              | (((long) array[offset + 5] & 0xff) << 16)
              | (((long) array[offset + 6] & 0xff) << 8)
              | (((long) array[offset + 7] & 0xff) << 0));           
    }
   
    public static byte[] intToBytes(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;
    }
   
    public static void intToBytes( int n, byte[] array, int offset ){
        array[3+offset] = (byte) (n & 0xff);
        array[2+offset] = (byte) (n >> 8 & 0xff);
        array[1+offset] = (byte) (n >> 16 & 0xff);
        array[offset] = (byte) (n >> 24 & 0xff);
    }   

    public static int bytesToInt(byte b[]) {
        return    b[3] & 0xff
               | (b[2] & 0xff) << 8
               | (b[1] & 0xff) << 16
               | (b[0] & 0xff) << 24;
    }

    public static int bytesToInt(byte b[], int offset) {
        return    b[offset+3] & 0xff
               | (b[offset+2] & 0xff) << 8
               | (b[offset+1] & 0xff) << 16
               | (b[offset] & 0xff) << 24;
    }

    public static byte[] uintToBytes( long 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;
    }

    public static void uintToBytes( long n, byte[] array, int offset ){
        array[3+offset] = (byte) (n );
        array[2+offset] = (byte) (n >> 8 & 0xff);
        array[1+offset] = (byte) (n >> 16 & 0xff);
        array[offset]   = (byte) (n >> 24 & 0xff);
    }

    public static long bytesToUint(byte[] array) {
        return ((long) (array[3] & 0xff))
             | ((long) (array[2] & 0xff)) << 8
             | ((long) (array[1] & 0xff)) << 16
             | ((long) (array[0] & 0xff)) << 24;
    }

    public static long bytesToUint(byte[] array, int offset) {  
        return ((long) (array[offset+3] & 0xff))
              | ((long) (array[offset+2] & 0xff)) << 8
             | ((long) (array[offset+1] & 0xff)) << 16
             | ((long) (array[offset]   & 0xff)) << 24;
    }

    public static byte[] shortToBytes(short n) {
        byte[] b = new byte[2];
        b[1] = (byte) ( n       & 0xff);
        b[0] = (byte) ((n >> 8) & 0xff);
        return b;
    }
   
    public static void shortToBytes(short n, byte[] array, int offset ) {       
        array[offset+1] = (byte) ( n       & 0xff);
        array[offset] = (byte) ((n >> 8) & 0xff);
    }
   
    public static short bytesToShort(byte[] b){
        return (short)( b[1] & 0xff
                      |(b[0] & 0xff) << 8 );
    }   

    public static short bytesToShort(byte[] b, int offset){
        return (short)( b[offset+1] & 0xff
                      |(b[offset]    & 0xff) << 8 );
    }

    public static byte[] ushortToBytes(int n) {
        byte[] b = new byte[2];
        b[1] = (byte) ( n       & 0xff);
        b[0] = (byte) ((n >> 8) & 0xff);
        return b;
    }   

    public static void ushortToBytes(int n, byte[] array, int offset ) {
        array[offset+1] = (byte) ( n       & 0xff);
        array[offset] = (byte)   ((n >> 8) & 0xff);
    }
    
    public static void ushortToBytesC(int n, byte[] array, int offset ) {
        array[offset] = (byte) ( n       & 0xff);
        array[offset+1] = (byte)   ((n >> 8) & 0xff);
    }


    public static int bytesToUshort(byte b[]) {
        return    b[1] & 0xff
               | (b[0] & 0xff) << 8;
    }   

    public static int bytesToUshort(byte b[], int offset) {
        return    b[offset+1] & 0xff
               | (b[offset]   & 0xff) << 8;
    }   

    public static byte[] ubyteToBytes( int n ){
        byte[] b = new byte[1];
        b[0] = (byte) (n & 0xff);
        return b;
    }

    public static void ubyteToBytes( int n, byte[] array, int offset ){
        array[offset+0] = (byte) (n & 0xff);
    }

    public static int bytesToUbyte( byte[] array ){           
        return array[0] & 0xff;
    }       

    public static int bytesToUbyte( byte[] array, int offset ){           
        return array[offset] & 0xff;
    }
    
    /**
     * 字符到字节转换
     *
     * @param ch
     * @return
     */
    public static void putChar(byte[] bb, char ch, int index) {
        int temp = (int) ch;
        // byte[] b = new byte[2];
        for (int i = 0; i < 2; i ++ ) {
             // 将最高位保存在最低位
            bb[index + i] = new Integer(temp & 0xff).byteValue();
            temp = temp >> 8; // 向右移8位
        }
    }

    /**
     * 字节到字符转换
     *
     * @param b
     * @return
     */
    public static char getChar(byte[] b, int index) {
        int s = 0;
        if (b[index + 1] > 0)
            s += b[index + 1];
        else
            s += 256 + b[index + 0];
        s *= 256;
        if (b[index + 0] > 0)
            s += b[index + 1];
        else
            s += 256 + b[index + 0];
        char ch = (char) s;
        return ch;
    }

    /**
     * float转换byte
     *
     * @param bb
     * @param x
     * @param index
     */
    public static void putFloat(byte[] bb, float x, int index) {
        // byte[] b = new byte[4];
        int l = Float.floatToIntBits(x);
        for (int i = 0; i < 4; i++) {
            bb[index + i] = new Integer(l).byteValue();
            l = l >> 8;
        }
    }

    /**
     * 通过byte数组取得float
     *
     * @param bb
     * @param index
     * @return
     */
    public static float getFloat(byte[] b, int index) {
        int l;
        l = b[index + 0];
        l &= 0xff;
        l |= ((long) b[index + 1] << 8);
        l &= 0xffff;
        l |= ((long) b[index + 2] << 16);
        l &= 0xffffff;
        l |= ((long) b[index + 3] << 24);
        return Float.intBitsToFloat(l);
    }
    /**
     * double转换byte
     *
     * @param bb
     * @param x
     * @param index
     */
    public static void putDouble(byte[] bb, double x, int index) {
        // byte[] b = new byte[8];
        long l = Double.doubleToLongBits(x);
        for (int i = 0; i < 4; i++) {
            bb[index + i] = new Long(l).byteValue();
            l = l >>8;
        }
    }

    /**
     * 通过byte数组取得float
     *
     * @param bb
     * @param index
     * @return
     */
    public static double getDouble(byte[] b, int index) {
        long l;
        l = b[0];
        l &= 0xff;
        l |= ((long) b[1] << 8);
        l &= 0xffff;
        l |= ((long) b[2] << 16);
        l &= 0xffffff;
        l |= ((long) b[3] << 24);
        l &= 0xffffffffl;
        l |= ((long) b[4] << 32);
        l &= 0xffffffffffl;
        l |= ((long) b[5] << 40);
        l &= 0xffffffffffffl;
        l |= ((long) b[6] << 48);
        l &= 0xffffffffffffffl;
        l |= ((long) b[7] << 56);
        return Double.longBitsToDouble(l);
    }
   
}