Java生成验证码功能实例代码
页面上输入验证码是比较常见的一个功能,实现起来也很简单.给大家写一个简单的生成验证码的示例程序,需要的朋友可以借鉴一下.
闲话少续,直接上代码.代码中的注释很详细.
packagecom.SM_test.utils;
importjava.awt.Color;
importjava.awt.Font;
importjava.awt.Graphics;
importjava.awt.Graphics2D;
importjava.awt.RenderingHints;
importjava.awt.geom.AffineTransform;
importjava.awt.image.BufferedImage;
importjava.io.File;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.OutputStream;
importjava.util.Arrays;
importjava.util.Random;
importjavax.imageio.ImageIO;
publicclassVerifyCodeUtils{
//使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
publicstaticfinalStringVERIFY_CODES="23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
privatestaticRandomrandom=newRandom();
/**
*使用系统默认字符源生成验证码
*@paramverifySize验证码长度
*@return
*/
publicstaticStringgenerateVerifyCode(intverifySize){
returngenerateVerifyCode(verifySize,VERIFY_CODES);
}
/**
*使用指定源生成验证码
*@paramverifySize验证码长度
*@paramsources验证码字符源
*@return
*/
publicstaticStringgenerateVerifyCode(intverifySize,Stringsources){
if(sources==null||sources.length()==0){
sources=VERIFY_CODES;
}
intcodesLen=sources.length();
Randomrand=newRandom(System.currentTimeMillis());
StringBuilderverifyCode=newStringBuilder(verifySize);
for(inti=0;i255)
fc=255;
if(bc>255)
bc=255;
intr=fc+random.nextInt(bc-fc);
intg=fc+random.nextInt(bc-fc);
intb=fc+random.nextInt(bc-fc);
returnnewColor(r,g,b);
}
privatestaticintgetRandomIntColor(){
int[]rgb=getRandomRgb();
intcolor=0;
for(intc:rgb){
color=color<<8;
color=color|c;
}
returncolor;
}
privatestaticint[]getRandomRgb(){
int[]rgb=newint[3];
for(inti=0;i<3;i++){
rgb[i]=random.nextInt(255);
}
returnrgb;
}
privatestaticvoidshear(Graphicsg,intw1,inth1,Colorcolor){
shearX(g,w1,h1,color);
shearY(g,w1,h1,color);
}
privatestaticvoidshearX(Graphicsg,intw1,inth1,Colorcolor){
intperiod=random.nextInt(2);
booleanborderGap=true;
intframes=1;
intphase=random.nextInt(2);
for(inti=0;i>1)
*Math.sin((double)i/(double)period
+(6.2831853071795862D*(double)phase)
/(double)frames);
g.copyArea(0,i,w1,1,(int)d,0);
if(borderGap){
g.setColor(color);
g.drawLine((int)d,i,0,i);
g.drawLine((int)d+w1,i,w1,i);
}
}
}
privatestaticvoidshearY(Graphicsg,intw1,inth1,Colorcolor){
intperiod=random.nextInt(40)+10;//50;
booleanborderGap=true;
intframes=20;
intphase=7;
for(inti=0;i>1)
*Math.sin((double)i/(double)period
+(6.2831853071795862D*(double)phase)
/(double)frames);
g.copyArea(i,0,1,h1,0,(int)d);
if(borderGap){
g.setColor(color);
g.drawLine(i,(int)d,i,0);
g.drawLine(i,(int)d+h1,i,h1);
}
}
}
publicstaticvoidmain(String[]args)throwsIOException{
Filedir=newFile("e:/abc");
intw=200,h=80;
for(inti=0;i<50;i++){
StringverifyCode=generateVerifyCode(4);
Filefile=newFile(dir,verifyCode+".jpg");
outputImage(w,h,file,verifyCode);
}
}
}
上面这段代码就能生成一个验证码,略微修改就能生成各种各样的形式,main方法可以测试.
下面为大家写一下如何返回到页面
packagecom.SM_test.saomiao.constroller;
importjava.io.IOException;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
importjavax.servlet.http.HttpSession;
importorg.springframework.stereotype.Controller;
importorg.springframework.web.bind.annotation.RequestMapping;
importcom.SM_test.utils.VerifyCodeUtils;
@Controller
publicclassIndexConstroller{
@RequestMapping(value="/index")
publicvoidindex(HttpServletRequestrequest,HttpServletResponseresponse)throwsIOException{
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires",0);
response.setContentType("image/jpeg");
//生成随机字串
StringverifyCode=VerifyCodeUtils.generateVerifyCode(4);
//存入会话session
HttpSessionsession=request.getSession(true);
session.setAttribute("rand",verifyCode.toLowerCase());
//生成图片
intw=200,h=80;
VerifyCodeUtils.outputImage(w,h,response.getOutputStream(),verifyCode);
}
}
很简单,用HttpServletResponse就OK了.
需要显示验证码的地方可以直接用img标签,地址就是该Controller的URL就OK了
以上所述是小编给大家介绍的Java生成验证码功能实例代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对毛票票网站的支持！