byte[] 转换成 int

一个完整的byte［］转换成int

byte[] b= new byte[4];  
        b[0] = 0x39;  
        b[1] = 0x69;  
        b[2] = （byte)0xcc;  
        b[3] = 0x55;  
         int dec_len = bytesToInt(b);  
     public static int bytesToInt(byte[] b) {  
       int temp = 0;  
       int res = 0;  
       for (int i = 0; i < b.length; i++) {  
            res <<= 8;  
           temp = b[i]&0xFF;  
           res |= temp;  
        }  
       return res;  
   }   

byte［］中的一部分转换成int

private static int toInt(byte[] data, int offset, int len) {
		int b = data[offset] & 0xff;
		for (int i = 1; i < len; i++) {
		b = (b << 8) | (data[offset + i] & 0xff);
		}
		return b;
		}