常用类

package 常用类;

import java.util.Random;

public class rand {

public static void main(String[] agrs) {
Random r = new Random();
System.out.print("布尔型："+r.nextBoolean());
System.out.print("整型："+r.nextInt(100));
System.out.print("长整型："+r.nextLong());
System.out.print("双精度："+r.nextDouble());
}
}

 

 

 

package 常用类;

import java.text.SimpleDateFormat;
import java.util.Date;

public class time {
public static void main(String[] args){
Date a=new Date();
SimpleDateFormat b=new SimpleDateFormat("yyyy年MM月dd日 HH时:mm分:ss秒");
System.out.println(b.format(a));
}
}