boolean与byte的互转

public static byte[] toBytes(boolean[] arrs){
        int f = 0;byte b = 0;
        byte[] ret = new byte[arrs.length/7 + (arrs.length%7==0?0:1)];
        for(int i=0; i<arrs.length; i+=8){
            for(int j=0; j<8; j++){
                if(i+j<arrs.length && arrs[i+j]){
                    b+= (1<<(7-j));
                }
                if(j==7){
                    ret[f++] = b;
                    b = 0;
                }
            }
        }
        return ret;
    }
    
    public static boolean[] toBoolean(byte[] bs, int length){
        boolean[] arrs = new boolean[8*bs.length];
        for(int i=0; i<bs.length; i++){
            int indx = i*8;
            byte b = bs[i];
            for(int j=7; j>=0; j--){
                arrs[indx + j] = (b&1)==1;
                b = (byte)(b>>1);
            }
        }
        return Arrays.copyOfRange(arrs, 0, length);
    }