验证码2.txt

两个动态生成验证码的jsp代码

<%@   page   contentType="image/jpeg"   import="java.awt.*,     
  java.awt.image.*,java.util.*,javax.imageio.*"   %>     
  <%     
  //   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();     
    
  //   设定背景色     
  g.setColor(new   Color(0xDCDCDC));     
  g.fillRect(0,   0,   width,   height);     
    
  //画边框     
  g.setColor(Color.black);     
  g.drawRect(0,0,width-1,height-1);     
    
  //   取随机产生的认证码(4位数字)     
  String   rand   =   request.getParameter("rand");     
  rand   =   rand.substring(0,rand.indexOf("."));     
  switch(rand.length())     
  {     
  case   1:   rand   =   "000"+rand;   break;     
  case   2:   rand   =   "00"+rand;   break;     
  case   3:   rand   =   "0"+rand;   break;     
  default:   rand   =   rand.substring(0,4);   break;     
  }     
    
  //   将认证码存入SESSION     
  session.setAttribute("rand",rand);     
    
  //   将认证码显示到图象中     
  g.setColor(Color.black);     
  Integer   tempNumber   =   new   Integer(rand);     
  String   numberStr   =   tempNumber.toString();     
    
  g.setFont(new   Font("Atlantic   Inline",Font.PLAIN,18));     
  String   Str   =   numberStr.substring(0,1);     
  g.drawString(Str,8,17);     
    
  Str   =   numberStr.substring(1,2);     
  g.drawString(Str,20,15);     
  Str   =   numberStr.substring(2,3);     
  g.drawString(Str,35,18);     
    
  Str   =   numberStr.substring(3,4);     
  g.drawString(Str,45,15);     
    
  //   随机产生88个干扰点，使图象中的认证码不易被其它程序探测到     
  Random   random   =   new   Random();     
  for   (int   i=0;i<20;i++)     
  {     
  int   x   =   random.nextInt(width);     
  int   y   =   random.nextInt(height);     
  g.drawOval(x,y,0,0);     
  }     
    
  //   图象生效     
  g.dispose();     
    
  //   输出图象到页面     
  ImageIO.write(image,   "JPEG",   response.getOutputStream());     
  %>