java冒泡排序

int[] a1 = {4, 2,3,5,1,};
for (int i = 0; i < a1.length-1; i++) {
    for (int j = 0; j < a1.length-1-i; j++) {
        int temp = a1[j];
        if(a1[j] > a1[j+1]) {
            a1[j] = a1[j+1];
            a1[j+1] = temp;
        }
    }
}