用jsp做个有彩纹的随机码

onions

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1^# 大中小发表于 2006-4-12 08:39 只看该作者

用jsp做个有彩纹的随机码

------------产生验证码图片的文件-----image.jsp-------------------------------------------, M& Z' u  L6 n# C% ~. p/ _& C

<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*" %>
<%!
Color getRandColor(int fc,int bc){//给定范围获得随机颜色
      Random random = new Random();& T) a1 J$ r1 ^' W9 Q. Z. @7 R
      if(fc>255) fc=255;% |# D( Z8 ]) J
      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);3 [3 ~4 p" S* _9 _- t  w" S
      return new Color(r,g,b);* X/ p4 @5 Y7 b
      }- O7 S2 `! B4 y8 u
%>
<%
//设置页面不缓存5 o- M/ O' w3 {: }7 g
response.setHeader("Pragma","No-cache");, }" x9 m4 c" u4 X# J( W1 u) v) S7 R
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);, r& a- f* o" H/ A+ O6 G
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// 在内存中创建图象- I6 Z2 i( X" y  r
int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);4 U9 X* }# z7 o- K/ p* A* R

// 获取图形上下文
Graphics g = image.getGraphics();/ P: K0 u- k5 z2 a) a

//生成随机类
Random random = new Random();
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// 设定背景色
g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);: ], g( e# _7 W/ j, [2 c* N& ^1 @- r
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//设定字体
g.setFont(new Font("Times New Roman",Font.PLAIN,18));

//画边框4 m4 b/ `8 i$ U% ~, I3 B
//g.setColor(new Color());' |6 _+ N. M( K- |' B
//g.drawRect(0,0,width-1,height-1);8 E0 {  l" C; Z  v

// 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);" i  n, A2 o: g1 o
      g.drawLine(x,y,x+xl,y+yl);
}8 i- L, |- r. j4 e
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// 取随机产生的认证码(4位数字)1 X6 v3 {. A! f3 m
String sRand="";# U3 d* B5 A) I. O/ q
for (int i=0;i<4;i++){  S) T8 B* u) i8 E
String rand=String.valueOf(random.nextInt(10));
sRand+=rand;9 ?* F0 J- L( d' V! {0 I
// 将认证码显示到图象中2 |, ?& h- s) [* M/ |
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1 ~/ a  p0 `/ G4 N- }
g.drawString(rand,13*i+6,16);
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// 将认证码存入SESSION' r% o9 K0 k1 x
session.setAttribute("rand",sRand);
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// 图象生效
g.dispose();

// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());
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%>
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---------------使用验证码图片的文件---------a.jsp------------------------------------* R6 x# Z3 r" F$ S+ d* t
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<%@ page contentType="text/html;charset=gb2312" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>认证码输入页面</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache">
<META HTTP-EQUIV="Expires" CONTENT="0"> ) i0 S& M# x: _+ \5 {3 h
</head>% M# C( j( ]( |- Z* ~+ z3 W2 O
<body>2 E# X) f) ~3 n) T9 n6 F: H
<form method=post action="check.jsp">
<table>
<tr>6 q# [+ q+ X+ \7 E
<td align=left>系统产生的认证码：</td>/ v+ g8 g& t- }% M+ {
<td><img border=0 src="image.jsp"></td>
</tr>8 Z7 v6 u" I' i) V2 U- W
<tr>% ]0 h. j, K. ]. R; e% F! ~
<td align=left>输入上面的认证码：</td>
<td><input type=text name=rand maxlength=4 value=""></td>
</tr>
<tr>
<td colspan=2 align=center><input type=submit value="提交检测"></td>6 }6 r: U( a: B8 J
</tr>, h2 V( Y0 L$ h- j. G8 b4 H, U
</form># F! `  D5 \( q* g0 j+ X
</body>$ t6 }) H6 A1 @, r
</html>8 o; h% [3 A7 h. P
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-----------------验证的页面----------check.jsp
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<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<html>
<head>
<title>认证码验证页面</title>/ {/ h4 b4 O& J. U, j/ v1 ^
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="Cache-Control" CONTENT="no-cache"> % s- w4 h9 v! p, }9 O/ ?' v, R3 t0 P
<META HTTP-EQUIV="Expires" CONTENT="0"> ! l0 E5 X/ o+ D$ f- M
</head>
2 t% {% O& n% V. @
<body>& i  n# l" o4 U. N
<% / h+ G# z# Y9 l( \1 ^% x2 X
String rand = (String)session.getAttribute("rand");
String input = request.getParameter("rand");, y6 o# }% ?& t
%>* w1 A$ ]8 s* A$ h+ _' v- y* n" Y
系统产生的认证码为： <%= rand %><br>
您输入的认证码为： <%= input %><br>$ q0 ]% J! H. P! u! k1 B
<br>$ A+ [! c% `$ G/ Y
<%
  if (rand.equals(input)) {
%>: V3 X- V6 {3 ~0 k7 |3 [% n7 A
<font color=green>输入相同，认证成功！</font>2 S, @5 L3 J1 C8 f4 {
<%$ i2 Z* Y) I! |3 E( Z$ }7 W: h
  } else {: [/ z# B) c; p& E9 l
%># J9 h! i9 Y2 [6 t! l( D
<font color=red>输入不同，认证失败！</font>
<%
  }
%>
</body>3 J9 ^5 T0 v9 }# p5 d* s
</html>

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