怎么得到随机数~~~在线等`~~ JSP里产生了随机数,我想赋值给一个文本框,然后做判断,然后根据值在页面输出各种不同的情况~~ 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 随机数生成器:package edu.zsu.zouang.util;import java.util.Random;public class Randomizer { private int lower; private int upper; private static Random random = new Random(); public Randomizer(int lower, int upper){ if(upper <= lower){ throw new IllegalStateException("Upper is smaller than lower!"); } this.lower = lower; this.upper = upper; } public Double nextDouble(){ return Double.valueOf(lower + (upper - lower) * random.nextDouble()); } public Integer nextInteger(){ return Integer.valueOf(lower +random.nextInt(upper - lower)); } public char[] nextBitArray(int length){ if(length <= 0){ throw new IllegalStateException("Length is less than ZERO!"); } char[] temp = new char[length]; for(int i = 0; i < length ; i++){ temp[i] = random.nextBoolean() ? '1' : '0'; } return temp; }} 楼上正解,Random类,顶1下,定义成Static的得了至于赋值给给text框,直接<%int(double) xxxxx = Randomizer.nexInt().intValue();%><input type=text,value="<%=xxxxx%>">试试可以吗 Rick_ang(东方未名) 的答案正确 这里就不写了 new Random().nextInt();或者用apache-commons-lang里面有一个随机类RandomUtils,非常方便 <%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" pageEncoding="GB2312"%><%!Color getRandColor(int fc,int bc){//给定范围获得随机颜色Random random = new Random();if(fc>255) fc=255;if(bc>255) bc=255;int r=fc+random.nextInt(bc-fc);int g=fc+random.nextInt(bc-fc);int b=fc+random.nextInt(bc-fc);return new Color(r,g,b);}%><%//设置页面不缓存response.setHeader("Pragma","No-cache");response.setHeader("Cache-Control","no-cache");response.setDateHeader("Expires", 0);// 在内存中创建图象int width=60, height=20;BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取图形上下文Graphics g = image.getGraphics();//生成随机类Random random = new Random();// 设定背景色g.setColor(getRandColor(200,250));g.fillRect(0, 0, width, height);//设定字体g.setFont(new Font("Times New Roman",Font.PLAIN,18));//画边框g.setColor(new Color(255,255,255));g.drawRect(0,0,width-1,height-1);// 随机产生155条干扰线,使图象中的认证码不易被其它程序探测到g.setColor(getRandColor(160,200));for (int i=0;i<155;i++){int x = random.nextInt(width);int y = random.nextInt(height);int xl = random.nextInt(22);int yl = random.nextInt(22);g.drawLine(x,y,x+xl,y+yl);}// 取随机产生的认证码(4位数字)String sRand="";for (int i=0;i<4;i++){String rand=String.valueOf(random.nextInt(10));sRand+=rand;// 将认证码显示到图象中g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同,可能是因为种子太接近,所以只能直接生成g.drawString(rand,13*i+6,16);}// 将认证码存入SESSIONsession.setAttribute("rand",sRand);// 图象生效g.dispose();// 输出图象到页面ImageIO.write(image, "JPEG", response.getOutputStream());%><%Integer ddd=new Integer(Integer.parseInt(sRand));if (ddd ==1111){ out.println("heeelel");}else{ out.println("1211"); }%>我的代码在这里,大家帮忙修改一下~~举个例子,如果随机数为8888,则要在页面上显示"好号码"之类的话~~ 头大的问题?高手请进…… 如何插入大量数据到Oracle数据库中 JSF调试的问题 使用DIV做一个页面,并使页面正好充满浏览器? 有谁做过用Java来按制扫描仪吗??? 跪求Tomcat配置问题,急!!!! 请教一个jbpm3.2的问题 标题排序 "帮助"怎么做?? 初学jsp,很菜的问题~~ 我是初学者,请帮忙看看 关于自动提交
package edu.zsu.zouang.util;import java.util.Random;public class Randomizer {
private int lower;
private int upper;
private static Random random = new Random();
public Randomizer(int lower, int upper){
if(upper <= lower){
throw new IllegalStateException("Upper is smaller than lower!");
}
this.lower = lower;
this.upper = upper;
}
public Double nextDouble(){
return Double.valueOf(lower + (upper - lower) * random.nextDouble());
}
public Integer nextInteger(){
return Integer.valueOf(lower +random.nextInt(upper - lower));
}
public char[] nextBitArray(int length){
if(length <= 0){
throw new IllegalStateException("Length is less than ZERO!");
}
char[] temp = new char[length];
for(int i = 0; i < length ; i++){
temp[i] = random.nextBoolean() ? '1' : '0';
}
return temp;
}
}
Random类,顶1下,定义成Static的得了
至于赋值给给text框,直接
<%int(double) xxxxx = Randomizer.nexInt().intValue();%>
<input type=text,value="<%=xxxxx%>">
试试可以吗
这里就不写了
里面有一个随机类
RandomUtils,非常方便
<%!
Color getRandColor(int fc,int bc){//给定范围获得随机颜色
Random random = new Random();
if(fc>255) fc=255;
if(bc>255) bc=255;
int r=fc+random.nextInt(bc-fc);
int g=fc+random.nextInt(bc-fc);
int b=fc+random.nextInt(bc-fc);
return new Color(r,g,b);
}
%>
<%
//设置页面不缓存
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);// 在内存中创建图象
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取图形上下文
Graphics g = image.getGraphics();//生成随机类
Random random = new Random();// 设定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);//设定字体
g.setFont(new Font("Times New Roman",Font.PLAIN,18));//画边框
g.setColor(new Color(255,255,255));
g.drawRect(0,0,width-1,height-1);// 随机产生155条干扰线,使图象中的认证码不易被其它程序探测到
g.setColor(getRandColor(160,200));
for (int i=0;i<155;i++)
{
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(22);
int yl = random.nextInt(22);
g.drawLine(x,y,x+xl,y+yl);
}// 取随机产生的认证码(4位数字)
String sRand="";
for (int i=0;i<4;i++){
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;// 将认证码显示到图象中g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
//调用函数出来的颜色相同,可能是因为种子太接近,所以只能直接生成
g.drawString(rand,13*i+6,16);
}// 将认证码存入SESSION
session.setAttribute("rand",sRand);
// 图象生效
g.dispose();// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());%>
<%
Integer ddd=new Integer(Integer.parseInt(sRand));
if (ddd ==1111)
{ out.println("heeelel");}
else
{
out.println("1211");
}
%>我的代码在这里,大家帮忙修改一下~~
举个例子,如果随机数为8888,则要在页面上显示"好号码"之类的话~~