常用的创建random的用法如下:
for (int i = 0; i < 10; i++) {
System.out.println(new Random().nextDouble()); // 0-1之间的随机double数
System.out.println(Math.random()); // 0-1之间的随机double数
}
工具类代码如下:
public class RandomUtils {
//范围内随机数,>=num1 ,<num2
public static int createInt(int num1,int num2)
{
int n=num1+(int)(Math.random()*(num2-num1));
return n;
}
//范围内随机数, >=num1 ,<num2m ,*1000 线程中用
public static int createMilliSecond(int num1,int num2)
{
return (num1+(int)(Math.random()*(num2-num1)))*1000;
}
public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
System.out.println(createInt(1,5));
System.out.println(createMilliSecond(1,5));
}
}
}