随机数图片验证码

util

package util ;  
  
import java.awt.Color;  
import java.awt.Font;  
import java.awt.Graphics;  
import java.awt.image.BufferedImage;  
import java.io.ByteArrayInputStream;  
import java.io.ByteArrayOutputStream;  
import java.util.Random;  
  
import javax.imageio.ImageIO;  
import javax.imageio.stream.ImageOutputStream;  
public class RandomNumUtil {      
private ByteArrayInputStream image;//图像      
private String str;//验证码        
private RandomNumUtil(){      
    init();//初始化属性      
}      
/*    
* 取得RandomNumUtil实例    
*/      
public static RandomNumUtil Instance(){      
return new RandomNumUtil();      
}      
/*    
* 取得验证码图片    
*/      
public ByteArrayInputStream getImage(){      
return this.image;      
}      
/*    
* 取得图片的验证码    
*/      
public String getString(){      
return this.str;      
}      
    
private void init() {      
// 在内存中创建图象      
int width=85, 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));      
// 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(12);      
int yl = random.nextInt(12);      
g.drawLine(x,y,x+xl,y+yl);      
}      
// 取随机产生的认证码(6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);      
}     
//赋值验证码     
this.str=sRand;      
    
//图象生效      
g.dispose();      
ByteArrayInputStream input=null;      
ByteArrayOutputStream output = new ByteArrayOutputStream();      
try{      
ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);      
ImageIO.write(image, "JPEG", imageOut);      
imageOut.close();      
input = new ByteArrayInputStream(output.toByteArray());      
}catch(Exception e){      
System.out.println("验证码图片产生出现错误："+e.toString());      
}      
    
this.image=input;/* 赋值图像 */      
}      
/*    
* 给定范围获得随机颜色    
*/      
private Color getRandColor(int fc,int bc){      
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);      
}     
}   

action

package action;

import java.io.ByteArrayInputStream;

import com.opensymphony.xwork2.ActionContext;

import util.RandomNumUtil;

public class RandomAction {
	private ByteArrayInputStream inputStream;
	
	//生成验证码方法
	public String execute()throws Exception{
		RandomNumUtil r = RandomNumUtil.Instance();
		this.setInputStream(r.getImage());
		ActionContext.getContext().getSession().put("random", r.getString());
		return "success";
	}

	public ByteArrayInputStream getInputStream() {
		return inputStream;
	}

	public void setInputStream(ByteArrayInputStream inputStream) {
		this.inputStream = inputStream;
	}
	
}

struts2

	
		image/jpeg
		inputStream
	

jsp