java web验证码生成总结(包括servlet、jsp和struts2实现)

时间：2021-12-24 10:23:33

一、使用纯Servlet实现验证码

(1)在web.xml配置: 

[java] view plaincopy
  1. <servlet>     
  2.     <servlet-name>image</servlet-name>     
  3.     <servlet-class>org.test.web.AuthImage</servlet-class>     
  4. </servlet>     
  5.     
  6. <servlet-mapping>     
  7.     <servlet-name>image</servlet-name>     
  8.  <url-pattern>/authImage</url-pattern>     
  9. </servlet-mapping>    

(2)servlet源码

[java] view plaincopy
  1. public class AuthImage extends HttpServlet     
  2. {     
  3.     
  4.     private static final String CONTENT_TYPE = "text/html; charset=gb2312";     
  5.     //设置字母的大小,大小     
  6.     private Font mFont = new Font("Times New Roman", Font.PLAIN, 17);     
  7.     public void init() throws ServletException     
  8.     {     
  9.         super.init();     
  10.     }     
  11.     Color getRandColor(int fc,int bc)     
  12.     {     
  13.         Random random = new Random();     
  14.         if(fc>255) fc=255;     
  15.         if(bc>255) bc=255;     
  16.         int r=fc+random.nextInt(bc-fc);     
  17.         int g=fc+random.nextInt(bc-fc);     
  18.         int b=fc+random.nextInt(bc-fc);     
  19.         return new Color(r,g,b);     
  20.     }     
  21.     
  22.     public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException     
  23.     {     
  24.         response.setHeader("Pragma","No-cache");     
  25.         response.setHeader("Cache-Control","no-cache");     
  26.         response.setDateHeader("Expires", 0);     
  27.         //表明生成的响应是图片     
  28.         response.setContentType("image/jpeg");     
  29.              
  30.         int width=100, height=18;     
  31.         BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);     
  32.              
  33.         Graphics g = image.getGraphics();     
  34.         Random random = new Random();     
  35.         g.setColor(getRandColor(200,250));     
  36.         g.fillRect(1, 1, width-1, height-1);     
  37.         g.setColor(new Color(102,102,102));     
  38.         g.drawRect(0, 0, width-1, height-1);     
  39.         g.setFont(mFont);     
  40.     
  41.         g.setColor(getRandColor(160,200));     
  42.     
  43.         //画随机线     
  44.         for (int i=0;i<155;i++)     
  45.         {     
  46.             int x = random.nextInt(width - 1);     
  47.             int y = random.nextInt(height - 1);     
  48.             int xl = random.nextInt(6) + 1;     
  49.             int yl = random.nextInt(12) + 1;     
  50.             g.drawLine(x,y,x + xl,y + yl);     
  51.         }     
  52.     
  53.         //从另一方向画随机线     
  54.         for (int i = 0;i < 70;i++)     
  55.         {     
  56.             int x = random.nextInt(width - 1);     
  57.             int y = random.nextInt(height - 1);     
  58.             int xl = random.nextInt(12) + 1;     
  59.             int yl = random.nextInt(6) + 1;     
  60.             g.drawLine(x,y,x - xl,y - yl);     
  61.         }     
  62.     
  63.         //生成随机数,并将随机数字转换为字母     
  64.         String sRand="";     
  65.         for (int i=0;i<6;i++)     
  66.         {     
  67.             int itmp = random.nextInt(26) + 65;     
  68.             char ctmp = (char)itmp;     
  69.             sRand += String.valueOf(ctmp);     
  70.             g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));     
  71.             g.drawString(String.valueOf(ctmp),15*i+10,16);     
  72.         }     
  73.     
  74.         HttpSession session = request.getSession(true);     
  75.         session.setAttribute("rand",sRand);     
  76.         g.dispose();     
  77.         ImageIO.write(image, "JPEG", response.getOutputStream());     
  78.     }     
  79.     public void destroy()     
  80.     {     
  81.     }     
  82. }    

(3)页面显示

[java] view plaincopy
  1. <img src="authImage"/>   

 

 

 

二、使用纯jsp实现验证码

[java] view plaincopy
  1. <%@ page language="java" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"   
  2.      contentType="image/jpeg" pageEncoding="UTF-8"%>  
  3.   
  4.   
  5. <%  //设置页面不缓存  
  6.    response.setHeader("Pragma","No-cache");  
  7.    response.setHeader("Cahce-Control","no-cache");  
  8.    response.setDateHeader("Expires",0);  
  9.    //在内存中创建图片  
  10.    int width=60,height=20;  
  11.    BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);  
  12.    //获取图形上下文  
  13.    Graphics g= image.getGraphics();  
  14.    //生成随机类  
  15.    Random random= new Random();  
  16.    //设置背景颜色  
  17.    g.setColor(new Color(160,200,100));  
  18.    g.fillRect(0,0,width,height);  
  19.    //设置字体  
  20.    g.setFont(new Font("Times New Roman",Font.PLAIN,18));  
  21.    //随机产生50条干扰线，使图形中的验证码不易被其他的程序探测到  
  22.     g.setColor(new Color(160,200,200));  
  23.    for(int i=0;i<50;i++)  
  24.    {  
  25.      int x=random.nextInt(width);  
  26.      int y=random.nextInt(height);  
  27.      int x1=random.nextInt(width);  
  28.      int y1=random.nextInt(height);  
  29.      g.drawLine(x,y,x+x1,y+y1);  
  30.    }  
  31.    //随机产生验证码（6位数字）  
  32.    String sRand="";  
  33.    for(int i=0;i<6;i++)  
  34.    {  
  35.      String rand=String.valueOf(random.nextInt(10));  
  36.      sRand+=rand;  
  37.      //将验证码显示到图象  
  38.      g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));  
  39.      g.drawString(rand,13*i+6,16);  
  40.    }  
  41.    session.setAttribute("rand",sRand);  //////将产生的验证码存储到sesson中  
  42.    g.dispose();  
  43.    ImageIO.write(image,"JPEG",response.getOutputStream());  
  44.    out.clear(); //***********  
  45.    out=pageContext.pushBody();//**********  
  46.  %>  

 

 

三、使用Struts2来实现验证码

(1)定义一个生成验证码的工具类

[java] view plaincopy
  1. package com.cn.hospital.util;  
  2.   
  3. import java.awt.Color;     
  4. import java.awt.Font;     
  5. import java.awt.Graphics;     
  6. import java.awt.image.BufferedImage;     
  7. import java.io.ByteArrayInputStream;     
  8. import java.io.ByteArrayOutputStream;     
  9. import java.util.Random;     
  10. import javax.imageio.ImageIO;     
  11. import javax.imageio.stream.ImageOutputStream;     
  12.   
  13. public class RandomNumUtil {  
  14.   
  15.     private ByteArrayInputStream image;//图像      
  16.     private String str;//验证码      
  17.         
  18.     private RandomNumUtil(){      
  19.     init();//初始化属性      
  20.     }      
  21.     /*    
  22.     * 取得RandomNumUtil实例    
  23.     */      
  24.     public static RandomNumUtil Instance(){      
  25.     return new RandomNumUtil();      
  26.     }      
  27.     /*    
  28.     * 取得验证码图片    
  29.     */      
  30.     public ByteArrayInputStream getImage(){      
  31.     return this.image;      
  32.     }      
  33.     /*    
  34.     * 取得图片的验证码    
  35.     */      
  36.     public String getString(){      
  37.     return this.str;      
  38.     }      
  39.         
  40.     private void init() {      
  41.     // 在内存中创建图象      
  42.     int width=85, height=20;      
  43.     BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);      
  44.     // 获取图形上下文      
  45.     Graphics g = image.getGraphics();      
  46.     // 生成随机类      
  47.     Random random = new Random();      
  48.     // 设定背景色      
  49.     g.setColor(getRandColor(200,250));      
  50.     g.fillRect(0, 0, width, height);      
  51.     // 设定字体      
  52.     g.setFont(new Font("Times New Roman",Font.PLAIN,18));      
  53.     // 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      
  54.     g.setColor(getRandColor(160,200));      
  55.     for (int i=0;i<155;i++)      
  56.     {      
  57.     int x = random.nextInt(width);      
  58.     int y = random.nextInt(height);      
  59.     int xl = random.nextInt(12);      
  60.     int yl = random.nextInt(12);      
  61.     g.drawLine(x,y,x+xl,y+yl);      
  62.     }      
  63.     // 取随机产生的认证码(6位数字)      
  64.     String sRand="";      
  65.     for (int i=0;i<6;i++){      
  66.     String rand=String.valueOf(random.nextInt(10));      
  67.     sRand+=rand;      
  68.     // 将认证码显示到图象中      
  69.     g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));      
  70.     // 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      
  71.     g.drawString(rand,13*i+6,16);      
  72.     }     
  73.     //赋值验证码     
  74.     this.str=sRand;      
  75.         
  76.     //图象生效      
  77.     g.dispose();      
  78.     ByteArrayInputStream input=null;      
  79.     ByteArrayOutputStream output = new ByteArrayOutputStream();      
  80.     try{      
  81.     ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);      
  82.     ImageIO.write(image, "JPEG", imageOut);      
  83.     imageOut.close();      
  84.     input = new ByteArrayInputStream(output.toByteArray());      
  85.     }catch(Exception e){      
  86.     System.out.println("验证码图片产生出现错误："+e.toString());      
  87.     }      
  88.         
  89.     this.image=input;/* 赋值图像 */      
  90.     }      
  91.     /*    
  92.     * 给定范围获得随机颜色    
  93.     */      
  94.     private Color getRandColor(int fc,int bc){      
  95.     Random random = new Random();      
  96.     if(fc>255) fc=255;      
  97.     if(bc>255) bc=255;      
  98.     int r=fc+random.nextInt(bc-fc);      
  99.     int g=fc+random.nextInt(bc-fc);      
  100.     int b=fc+random.nextInt(bc-fc);      
  101.     return new Color(r,g,b);      
  102.     }     
  103. }  

(2)定义一个验证码输出的action

[java] view plaincopy
  1. package com.cn.hospital.action;  
  2.   
  3. import java.io.ByteArrayInputStream;  
  4. import java.io.ByteArrayOutputStream;  
  5.   
  6. import org.springframework.context.annotation.Scope;  
  7. import org.springframework.stereotype.Controller;  
  8.   
  9. import com.cn.hospital.util.RandomCharUtil;  
  10. import com.cn.hospital.util.RandomNumUtil;  
  11. import com.opensymphony.xwork2.ActionContext;  
  12. import com.opensymphony.xwork2.ActionSupport;  
  13.   
  14. @Controller("utilAction")  
  15. @Scope("prototype")  
  16. public class UtilAction extends ActionSupport{  
  17.       
  18.     private static final long serialVersionUID = -7193209177116825032L;  
  19.     private ByteArrayInputStream inputStream;   
  20.       
  21.     private int width;     
  22.     private int height;     
  23.     private int fontSize;     
  24.     private int codeLength;   
  25.     private int disturbType;  
  26.       
  27.     public String validNumGenerate() throws Exception{  
  28.         RandomNumUtil rdnu=RandomNumUtil.Instance();      
  29.         this.setInputStream(rdnu.getImage());//取得带有随机字符串的图片      
  30.         ActionContext.getContext().getSession().put("random", rdnu.getString());//取得随机字符串放入HttpSession      
  31.         return SUCCESS;      
  32.     }   
  33.       
  34.       
  35.     public void setInputStream(ByteArrayInputStream inputStream) {      
  36.         this.inputStream = inputStream;      
  37.     }     
  38.       
  39.     public ByteArrayInputStream getInputStream() {      
  40.         return inputStream;      
  41.     }  
  42.       
  43.   
  44. }  

(3)struts.xml配置

[java] view plaincopy
  1. <!-- 产生随机验证码 -->  
  2.         <action name="randNum" class="utilAction" method="validNumGenerate">        
  3.            <result name="success" type="stream">        
  4.                 <param name="contentType">image/jpeg</param>        
  5.                 <param name="inputName">inputStream</param>        
  6.            </result>     
  7.         </action>   

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