java代码记录时间方法

public static void main(String[] args) {
        long start = System.currentTimeMillis();
        for(int i = 0; i < 1000000; i++) {
            System.out.println("x");
        }
        long end = System.currentTimeMillis();
        System.out.println(end - start);
        System.out.println(d.getTime());
    }