randomutil.java

基于struts+hibernate的电子商务网站。可运行。数据库mysql

package dao;


import java.sql.Date;
import java.util.Random;

public class RandomUtil {
	private static Random rand = new Random();
	
	public static boolean getNextBoolean(double scale){
		return (rand.nextDouble()<scale?true:false);
	}
	public static int getNextInt(int start,int end){
		if((end-start)<0) return 0;
		if((end-start)==0) return start;
		return rand.nextInt(end-start)+start;
	}
	public static int nextInt(){
		return rand.nextInt();
	}
	public static int nextInt(int n){
		return rand.nextInt(n);
	}
	public static Date getNextDate(Date start,Date end){
		long extend = end.getTime()-start.getTime();		
		if(extend<=0) return null;
		extend = (long)(rand.nextDouble()*extend);			
		return new Date(start.getTime()+extend);
	}
	public static Date getNextDate(Date start,Date end,int floor,int i){
		long extend = end.getTime()-start.getTime();		
		if(extend<=0) return null;
		extend = (long)(rand.nextDouble()*extend);			
		return new Date(start.getTime()+extend);
	}
	public static Random getRandom(){
		return rand;
	}
}