java动态生成验证码

生成验证码代码：

package com.accor.crm.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class VerifyCodeUtil {
private static final int VERIFY_CODE_TYPE_NUMBER = 1;
private static final int VERIFY_CODE_TYPE_LETTER_DEFAULT = 2;
private static final int VERIFY_CODE_WIDTH_DEFAULT = 80;
private static final int VERIFY_CODE_HEIGHT_DEFAULT = 20;

public static void create(int type,String sessionVerifyCodeName, HttpServletRequest request, HttpServletResponse response) throws IOException{
create(VERIFY_CODE_WIDTH_DEFAULT,VERIFY_CODE_HEIGHT_DEFAULT,type,sessionVerifyCodeName,request,response);
}

public static void create(String sessionVerifyCodeName,HttpServletRequest request, HttpServletResponse response) throws IOException{
create(VERIFY_CODE_WIDTH_DEFAULT,VERIFY_CODE_HEIGHT_DEFAULT,VERIFY_CODE_TYPE_LETTER_DEFAULT,sessionVerifyCodeName,request,response);
}

public static void create(int width, int height,int type,String sessionVerifyCodeName, HttpServletRequest request, HttpServletResponse response) throws IOException{
response.setContentType("image/jpeg");
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);
HttpSession session=request.getSession(false);

BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
Random random = new Random();

Font mFont = new Font("Arial", Font.PLAIN, 18);
g.setColor(getRandColor(200,250));
g.fillRect(1, 1, width, height);
g.setFont(mFont);
g.setColor(new Color(102,102,102));
g.drawRect(0, 0, width-1, height-1);
g.setColor(getRandColor(160,200));
for (int i=0;i<20;i++){
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(6) + 1;
int yl = random.nextInt(12) + 1;
g.drawLine(x,y,x + xl,y + yl);
}

for (int i=0;i<20;i++){
int x = random.nextInt(width - 1);
int y = random.nextInt(height - 1);
int xl = random.nextInt(12) + 1;
int yl = random.nextInt(6) + 1;
g.drawLine(x,y,x - xl,y - yl);
}

String sRand="";
for (int i=0;i<4;i++){
String randTemp = "";
if(VERIFY_CODE_TYPE_NUMBER==type){
randTemp = String.valueOf(random.nextInt(10));
sRand += randTemp;
}else{
randTemp = getRandomChar();
sRand += randTemp;
}
g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
g.drawString(randTemp,15*i+10,15);
}

session.setAttribute(sessionVerifyCodeName,sRand);

g.dispose();

ServletOutputStream responseOutputStream =response.getOutputStream();
ImageIO.write(image, "JPEG", responseOutputStream);
responseOutputStream.flush();
responseOutputStream.close();
}

public static 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);
}

private static String getRandomChar(){
int rand = (int)Math.round(Math.random() * 2);
long itmp = 0;
char ctmp = '\\';
switch (rand) {
case 1:
itmp = Math.round(Math.random() * 25 + 65);
ctmp = (char)itmp;
return String.valueOf(ctmp);
case 2:
itmp = Math.round(Math.random() * 25 + 97);
ctmp = (char)itmp;
return String.valueOf(ctmp);
default :
itmp = Math.round(Math.random() * 9);
return String.valueOf(itmp);
}
}
}

controller调用：

public ModelAndView createVerifyCode(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
VerifyCodeUtil.create(ConstantUtil.SESSIOIN_ATTRIBUTE_VERIFYCODE, request, response);
return null;
}

jsp页面调用代码：

function verifyCodeAgain(){
$("#verifyCodeImgId").attr("src",$("#verifyCodeImgId").attr("src")+"?param=0");
}

<a href="ae/aeLogin.htm#" title="<fmt:message key="login.verifyCode.title.again"/>" onclick="verifyCodeAgain()">
<img id="verifyCodeImgId" src="<c:url value='/createVerifyCode.htm'/>" border="0"/>
</a>

xml配置：

<bean id="createVerifyCodeController" class="com.accor.crm.view.controller.ae.CreateVerifyCodeController">
<property name="methodNameResolver">
<ref bean="InternalPathMethodNameResolver" />
</property>
</bean>

<prop key="/createVerifyCode.htm">createVerifyCodeController</prop>

//得到验证码

String verifyCode = (String)request.getSession().getAttribute(ConstantUtil.SESSIOIN_ATTRIBUTE_VERIFYCODE);