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java生成随机验证码

发布时间: 2021-03-24 06:40:24

A. J2EE中JSP页面怎么获取java类里生成的随机验证码

直接 <img src="your image request url" >

B. 用java随机生成四位验证码，只求编程代码

不知道你问的是不是生成这种图片验证码？
如果只要一个随机四位数那这行代码就够了(new Random().nextInt(9000) + 1000;),
如果是生成页面图片验证码就是下面的了:
//设定响应模式
resp.setContentType("image/jpeg");

// 生成令牌环数据;
Integer token = new Random().nextInt(9000) + 1000;

// 保存令牌环数据到session中
req.getSession().setAttribute(IMAGE_TOKEN_NAME, token);

// 生成令牌环图片
ServletOutputStream out = resp.getOutputStream();
BufferedImage img = new BufferedImage(60, 20,
BufferedImage.TYPE_INT_RGB);
Graphics g = img.getGraphics();
g.setColor(Color.YELLOW);
g.fillRect(0, 0, img.getWidth(), img.getHeight());
g.setColor(Color.BLUE);
g.setFont(new Font("", Font.BOLD, 18));
g.drawString(String.valueOf(token), 10, 16);
ImageIO.write(img, "jpg", out);
out.close();

C. java swing随机验证码

(HttpServletRequestrequest,
			HttpServletResponseresponse)throwsServletException,IOException{
			
			response.setContentType("image/jpeg");
			response.setHeader("Pragma","No-cache");
			response.setHeader("Cache-Control","no-cache");
			response.setDateHeader("Expires",0);
			HttpSessionsession=request.getSession();
			
			intwidth=60,height=20;
			
			BufferedImageimage=newBufferedImage(width,height,
			BufferedImage.TYPE_INT_RGB);
			
			//获取图形上下文
			Graphicsg=image.getGraphics();
			
			//生成随机类
			Randomrandom=newRandom();
			
			//设定背景色
			g.setColor(getRandColor(200,250));
			g.fillRect(0,0,width,height);
			
			//设定字体
			g.setFont(newFont("TimesNewRoman",Font.PLAIN,18));
			
			//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(inti=0;i<155;i++){
			intx=random.nextInt(width);
			inty=random.nextInt(height);
			intxl=random.nextInt(12);
			intyl=random.nextInt(12);
			g.drawLine(x,y,x+xl,y+yl);
			}
			
			//取随机产生的认证码(4位数字)
			StringsRand="";
			for(inti=0;i<4;i++){
			Stringrand=String.valueOf(random.nextInt(10));
			sRand+=rand;
			//将认证码显示到图象中
			g.setColor(newColor(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();
			=response.getOutputStream();
			//输出图象到页面
			ImageIO.write(image,"JPEG",responseOutputStream);
			
			//以下关闭输入流！
			responseOutputStream.flush();
			responseOutputStream.close();
			}
			
		static	ColorgetRandColor(intfc,intbc){
			//给定范围获得随机颜色
			Randomrandom=newRandom();
			if(fc>255)
			fc=255;
			if(bc>255)
			bc=255;
			intr=fc+random.nextInt(bc-fc);
			intg=fc+random.nextInt(bc-fc);
			intb=fc+random.nextInt(bc-fc);
			returnnewColor(r,g,b);
			}
			
			/**
			*HandlestheHTTPGETmethod.
			*
			*@paramrequest
			*servletrequest
			*@paramresponse
			*servletresponse
			*/
			protectedvoiddoGet(HttpServletRequestrequest,
			HttpServletResponseresponse)throwsServletException,IOException{
			processRequest(request,response);
			}

这个是我web里用的验证码，你可以改改

D. Java上机怎么随机生成验证码

我在网上看过PHP做的一个随机字符串生成程序，很简单的喔，亲：
function randStr($length=8)
{
$str = substr(md5(time()), 0, $length);
return $str;
}
具体步骤就是先获得当前时间毫秒数，再md5加密后取前多少位就行了。

E. Java Swing中随机验证码如何实现

根本思想是使用
随机数
具体实现：
1.
生成一个随机数
2.
将随机数使用全局变量保留
3.
将随机数设置成按钮的提示文字
4.
编写点击之后重新生成随机数，并且绑定到按钮上
5.
验证
如果需要实例，请留下邮箱！^_^

F. Java产生随机验证码

package com.you100.util;
import java.util.Random;
public class Picture {
public static void main(String[] args) {
Random ran=new Random();char ch[] =new char[]{'a','b','c','d','e','f','g','@','1','2','3','4','5'};

StringBuilder str=new StringBuilder("");
for(int i=0;i<4;i++){

str.append(ch[ran.nextInt(ch.length)]);

}
System.out.println("验证码="+str);

}}

在控制台上随回机生成答验证码

G. 如何在java中生成验证码在页面生成

以下是我写的生成的图片验证码

//调用验证码生成并把验证码返回页面
Map<String,BufferedImage>imageMap=ImageUtil.createImage();
		Stringcode=imageMap.keySet().iterator().next();
		session.setAttribute("imageCode",code);
		BufferedImageimage=imageMap.get(code);
		response.setContentType("image/jpeg");
		OutputStreamops=response.getOutputStream();
		ImageIO.write(image,"jpeg",ops);
		ops.close();

//生成验证码工具类
publicfinalclassImageUtil{
	
	privatestaticfinalchar[]chars={'A','B','C','D','E','F','G','H','I','J',
'K','L','M','N','O','P','Q','R','S','T','U','V','W',
'X','Y','Z','0','1','2','3','4','5','6','7','8','9'};
	privatestaticfinalintSIZE=4;
	privatestaticfinalintLINES=5;
	privatestaticfinalintWIDTH=80;
	privatestaticfinalintHEIGHT=40;
	privatestaticfinalintFONT_SIZE=30;

	publicstaticMap<String,BufferedImage>createImage(){
		StringBuffersb=newStringBuffer();
		BufferedImageimage=newBufferedImage(WIDTH,HEIGHT,
				BufferedImage.TYPE_INT_RGB);
		Graphicsgraphic=image.getGraphics();
		graphic.setColor(Color.LIGHT_GRAY);
		graphic.fillRect(0,0,WIDTH,HEIGHT);
		Randomran=newRandom();
		//画随机字符
		for(inti=1;i<=SIZE;i++){
			intr=ran.nextInt(chars.length);
			graphic.setColor(getRandomColor());
			graphic.setFont(newFont(null,Font.BOLD+Font.ITALIC,FONT_SIZE));
			graphic.drawString(chars[r]+"",(i-1)*WIDTH/SIZE,HEIGHT/2);
			sb.append(chars[r]);
		}
		//画干扰线
		for(inti=1;i<=LINES;i++){
			graphic.setColor(getRandomColor());
			graphic.drawLine(ran.nextInt(WIDTH),ran.nextInt(HEIGHT),
					ran.nextInt(WIDTH),ran.nextInt(HEIGHT));
		}
		Map<String,BufferedImage>map=newHashMap<String,BufferedImage>();
		map.put(sb.toString(),image);
		returnmap;
	}

	(){
		Randomran=newRandom();
		Colorcolor=newColor(ran.nextInt(256),ran.nextInt(256),ran.nextInt(256));
		returncolor;
	}

	(BufferedImageimage)
			throwsIOException{
		ByteArrayOutputStreambos=newByteArrayOutputStream();
		JPEGImageEncoderencoder=JPEGCodec.createJPEGEncoder(bos);
		encoder.encode(image);
		byte[]imageBts=bos.toByteArray();
		InputStreamin=newByteArrayInputStream(imageBts);
		returnin;
	}
}

H. JAVA程序中，随机产生一个6位的验证码 (是由0

import java.util.Random;

public class TestRandom {
public String getRandStr(int charCount) {
String charValue = "";
for (int i = 0; i < charCount; i++){
char c = (char) (randomInt(0,26)+'a');
charValue += String.valueOf(c);
}
return charValue;
}
public String getRandNum(int charCount) {
String charValue = "";
for (int i = 0; i < charCount; i++){
char c = (char) (randomInt(0,10)+'0');
charValue += String.valueOf(c);
}
return charValue;
}

public int randomInt(int from, int to){
Random r = new Random();
return from + r.nextInt(to - from);
}
}

I. 用java实现：随机获取4位的验证码

验证码是指网页的验证码还是手机的验证码

下面是随机生成四位数的相关代码

importjava.util.Random;

publicclassRandomTest{
publicstaticvoidmain(String[]args){
System.out.println("Math.random得到小数");
System.out.println(Math.round(Math.random()*10000));
System.out.println("Random");
System.out.println(newRandom().nextInt(9999));
System.out.println("字符串前面补0的话就这样String.format");
System.out.println(String.format("%04d",newRandom().nextInt(9999)));
}
}

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