用一个Int 存贮多个标志，还有什么办法？

假设要记录每个锻炼周期16天哪天完成锻炼

现用一个int来表示，去后16位，用01标志是否去锻炼过，1代表去过，0代表没有

import java.util.Arrays;

public class IntBitUtil {
private static int DEFALT_LEN = 2<<3;
public static void main(String[] args) {
int a = 56171;
byte [] b = intToBits (a);
int va = bitsToInt(b);
System.out.println(Arrays.toString(b));
System.out.println(va);
System.out.println(2<<3);
}
/**
* <p> put 56171
* <p> get[1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1]
*/
public static byte[] intToBits(int val) {
byte[] bits = new byte[DEFALT_LEN];
for (int i = 0; i < bits.length; i++) {
bits[bits.length -1-i] = (byte)((val>>i)& 0x1);
}
return bits;
}
/**
* <p> put[1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1]
* <p> get 56171
*/
public static int bitsToInt(byte[] bits) {
int value = 0;
for (int i = 0; i < bits.length; i++) {
value += bits[i]<<(bits.length-1-i);
}
return value;
}
}

output:

[1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1]
56171
16

public static byte[] intToBits(int val) {

byte[] bits = new byte[DEFALT_LEN];

for (int i = 0; i < bits.length; i++) {

bits[i] = (byte)((val>>i)& 0x1);

}

return bits;

}

public static int bitsToInt(byte[] bits) {

int value = 0;

for (int i = 0; i < bits.length; i++) {

value += bits[i]<<(i);

}

return value;

}