用户登录实现.docx

（2）验证码生成页面

<%@pagecontentType="image/jpeg"

import="java.awt.*,

java.awt.image.*,java.util.*,javax.imageio.*"pageEncoding="utf-8"%>

<%!

//随机颜色

ColorgetRandColor（intfc,intbc）

{

Randomrandom=newRandom（）;

if（fc>255）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）;

}

%>

<%

//用于指示请示或响应消息不能缓存

out.clear（）;

response.setHeader（"Pragma","No-cache"）;

response.setHeader（"Cache-Control","no-cache"）;

response.setDateHeader（"Expires",0）;//在内存中创建图象

//用于指示请示或响应消息不能缓存

intwidth=60,height=20;

//创建一个画布

BufferedImageimage=newBufferedImage（width,height,BufferedImage.TYPE_INT_RGB）;

//获取画布的画笔

Graphicsg=image.getGraphics（）;

Randomrandom=newRandom（）;

//设定图像背景色（因为是做背景，所以偏淡）

g.setColor（getRandColor（200,250））;

g.fillRect（0,0,width,height）;

//设置字体和颜色

g.setFont（newFont（"TimesNewRoman",Font.PLAIN,18））;

g.setColor（getRandColor（160,200））;

//随机产生155条干扰线条

for（inti=0;i<155;i++）

{

intx=random.nextInt（width）;

inty=random.nextInt（height）;

intxl=random.nextInt（12）;

intyl=random.nextInt（12）;

g.drawLine（x,y,x+xl,y+yl）;

}

//随机产生4位认证码

StringsRand="";

for（inti=0;i<4;i++）{

Stringrand=String.valueOf（random.nextInt（10））;

sRand+=rand;

g.setColor（newColor（20+random.nextInt（110）,20+random.nextInt（110）,20+random.nextInt（110）））;

g.drawString（rand,13*i+6,16）;

}

//将验证码存入SESSION

session.setAttribute（"sRand",sRand）;

//图片生效

g.dispose（）;

//输出图片到页面

ImageIO.write（image,"JPEG",response.getOutputStream（））;

%>

3.dao

packagedao;

importjava.sql.Connection;

importjava.sql.PreparedStatement;

importjava.sql.ResultSet;

importmodel.User;

publicclassUserDao{

publicUserlogin（Connectioncon,Useruser）throwsException{

UserresultUser=null;

Stringsql="select*fromt_userwhereuserName=?

andpassword=?

";

PreparedStatementpstmt=con.prepareStatement（sql）;

pstmt.setString（1,user.getUserName（））;

pstmt.setString（2,user.getPassword（））;

ResultSetrs=pstmt.executeQuery（）;

if（rs.next（））{

resultUser=newUser（）;

resultUser.setUserId（rs.getInt（"userId"））;

resultUser.setUserName（rs.getString（"userName"））;

resultUser.setPassword（rs.getString（"password"））;

resultUser.setRoleId（rs.getInt（"roleId"））;

}

returnresultUser;

}

}

4.model

packagemodel;

publicclassUser{

privateintuserId;

privateStringuserName;

privateStringpassword;

privateintuserType;

privateintroleId;

privateStringuserDescription;

publicUser（）{

super（）;

//TODOAuto-generatedconstructorstub

}

publicUser（StringuserName,Stringpassword）{

super（）;

this.userName=userName;

this.password=password;

}

publicintgetUserId（）{

returnuserId;

}

publicvoidsetUserId（intuserId）{

this.userId=userId;

}

publicStringgetUserName（）{

returnuserName;

}

publicvoidsetUserName（StringuserName）{

this.userName=userName;

}

publicStringgetPassword（）{

returnpassword;

}

publicvoidsetPassword（Stringpassword）{

this.password=password;

}

publicintgetUserType（）{

returnuserType;

}

publicvoidsetUserType（intuserType）{

this.userType=userType;

}

publicintgetRoleId（）{

returnroleId;

}

publicvoidsetRoleId（introleId）{

this.roleId=roleId;

}

publicStringgetUserDescription（）{

returnuserDescription;

}

publicvoidsetUserDescription（StringuserDescription）{

this.userDescription=userDescription;

}

}

5.util

packageutil;

importjava.sql.Connection;

importjava.sql.DriverManager;

publicclassDbUtil{

privateStringdbUrl="jdbc:

mysql:

//localhost:

3306/db_rbps";

privateStringdbUserName="root";

privateStringdbPassword="123456";

privateStringjdbcName="com.mysql.jdbc.Driver";

publicConnectiongetCon（）throwsException{

Class.forName（jdbcName）;

Connectioncon=DriverManager.getConnection（dbUrl,dbUserName,dbPassword）;

returncon;

}

publicvoidcloseCon（Connectioncon）throwsException{

if（con!

=null）{

con.close（）;

}

}

publicstaticvoidmain（String[]args）{

DbUtildbUtil=newDbUtil（）;

try{

dbUtil.getCon（）;

System.out.println（"数据库连接成功！

"）;

}catch（Exceptione）{

//TODOAuto-generatedcatchblock

e.printStackTrace（）;

System.out.println（"数据库连接失败！

"）;

}

}

}

packageutil;

publicclassStringUtil{

publicstaticbooleanisEmpty（Stringstr）{

if（"".equals（str）||str==null）{

returntrue;

}else{

returnfalse;

}

}

publicstaticbooleanisNotEmpty（Stringstr）{

if（!

"".equals（str）&&str!

=null）{

returntrue;

}else{

returnfalse;

}

}

}

6.web

packageweb;

importjava.io.IOException;

importjava.sql.Connection;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importjavax.servlet.http.HttpSession;

importdao.UserDao;

importmodel.User;

importutil.DbUtil;

importutil.StringUtil;

publicclassUserServletextendsHttpServlet{

/**

*

*/

privatestaticfinallongserialVersionUID=1L;

DbUtildbUtil=newDbUtil（）;

UserDaouserDao=newUserDao（）;

@Override

protectedvoiddoGet（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

//TODOAuto-generatedmethodstub

this.doPost（request,response）;

}

@Override

protectedvoiddoPost（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

request.setCharacterEncoding（"utf-8"）;

Stringaction=request.getParameter（"action"）;

if（"login".equals（action））{

login（request,response）;

}

}

privatevoidlogin（HttpServletRequestrequest,HttpServletResponseresponse）

throwsServletException,IOException{

HttpSessionsession=request.getSession（）;

StringuserName=request.getParameter（"userName"）;

Stringpassword=request.getParameter（"password"）;

StringimageCode=request.getParameter（"imageCode"）;

request.setAttribute（"userName",userName）;

request.setAttribute（"password",password）;

request.setAttribute（"imageCode",imageCode）;

if（StringUtil.isEmpty（userName）||StringUtil.isEmpty（password））{

request.setAttribute（"error","用户名或密码为空！

"）;

request.getRequestDispatcher（"../login.jsp"）.forward（request,response）;

return;

}

if（StringUtil.isEmpty（imageCode））{

request.setAttribute（"error","验证码为空！

"）;

request.getRequestDispatcher（"../login.jsp"）.forward（request,response）;

return;

}

if（!

imageCode.equals（session.getAttribute（"sRand"）））{

request.setAttribute（"error","验证码错误！

"）;

request.getRequestDispatcher（"../login.jsp"）.forward（request,response）;

return;

}

Useruser=newUser（userName,password）;

Connectioncon=null;

try{

con=dbUtil.getCon（）;

UsercurrentUser=userDao.login（con,user）;

if（currentUser==null）{

request.setAttribute（"error","用户名或密码错误！

"）;

request.getRequestDispatcher（"../login.jsp"）.forward（request,response）;

return;

}else{

session.setAttribute（"currentUser",currentUser）;

response.sendRedirect（"../main.jsp"）;

}

}catch（Exceptione）{

//TODOAuto-generatedcatchblock

e.printStackTrace（）;

}finally{

try{

dbUtil.closeCon（con）;

}catch（Exceptione）{

//TODOAuto-generatedcatchblock

e.printStackTrace（）;

}

}

}

}

7.sql

insertinto`t_user`（`userId`,`userName`,`password`,`userType`,`roleId`,`userDescription`）values（1,'java1234','123456',1,NULL,NULL）