java int轉byte數組

int 轉 byte[]   低字節在前（低字節序）

public static byte[] toLH(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;  
}

int 轉 byte[]   高字節在前（高字節序）

public static byte[] toHH(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;  
}

byte[] 轉 int 低字節在前（低字節序）

public int toInt(byte[] b){
    int res = 0;
    for(int i=0;i<b.length;i++){
        res += (b[i] & 0xff) << (i*8);
    }
    return res;
}

byte[] 轉 int 高字節在前（高字節序）

public static int toInt(byte[] b){
    int res = 0;
    for(int i=0;i<b.length;i++){
        res += (b[i] & 0xff) << ((3-i)*8);
    }
    return res;
}