實(shí)現(xiàn) java web 頁(yè)面的登錄驗(yàn)證

本案例中的程序主要通過(guò) java jdbc-odbc 驅(qū)動(dòng)連接 sql2000 數(shù)據(jù)庫(kù) , 并依據(jù)數(shù)據(jù)庫(kù)中的用戶(hù)表信息驗(yàn)證客戶(hù)端登錄請(qǐng)求提交的用戶(hù)名和密碼 .

1.?????? sql2000 數(shù)據(jù)庫(kù)中建立數(shù)據(jù)庫(kù) test..

2.?????? 在 test 數(shù)據(jù)庫(kù)中建表 userid
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3. 在表中增加數(shù)據(jù)
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3.?????? 建立數(shù)據(jù)源 test
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Eclipse 開(kāi)發(fā)環(huán)境

4. 新建項(xiàng)目
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4.?????? 新建 WEB 下面的 HTML 頁(yè)面 index.html.

5.?????? 寫(xiě)入代碼 :

<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >

< html >

< head >

< meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" >

< title > 系統(tǒng)登錄 </ title >

</ head >

< body >

??? < center > ???

??? < h2 > 系統(tǒng)登錄 </ h2 > ???

??? < form action = "login.jsp" method = "post" >

??????? < Input type = "text" name = "uid" maxlength = 8 style = "width:150" >< br >

??????? < Input type = "password" name = "upwd" maxlength = 8 style = "width:150" >< br >

??????? < Input type = "submit" value = " 登陸" >

??????? < Input type = "reset" value = " 取消" >

??? </ form >

??? </ center >

</ body >

</ html >

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界面如右:

6.?????? 新建 jsp 文件 login.jsp.

<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %>

<%@ page import = "java.sql.*" %>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >

< html >

< head >

< meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" >

< title > 驗(yàn)證頁(yè)面 </ title >

</ head >

< body >

<%

String username = request.getParameter( "uid" );

String password = request.getParameter( "upwd" );

if (username != null && !username.equals( "" )){

try {

??? /*

??? ?* 連接數(shù)據(jù)庫(kù)

??? ?*/

??????? Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" );

??????? Connection con=DriverManager.getConnection( "jdbc:odbc:test" , "" , "" );

??????? Statement stmt =con.createStatement();

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??? String sql = "select * from userid where name='" + username + "'" ;

??? sql += " and psw='" + password + "'" ;? // 準(zhǔn)備查詢(xún)語(yǔ)句

??? ResultSet rs=stmt.executeQuery( sql );

??? if ( rs.next() ){

??? session.setAttribute( "login" , "ok" ); // 驗(yàn)證通過(guò)之后，跳轉(zhuǎn)到后續(xù)頁(yè)面

??? session.setAttribute( "uname" ,username);

%>

??????? < jsp:forward page = "main.jsp" />

<%

??? } else

? ?????? out.println( " 錯(cuò)誤的用戶(hù)名和密碼" );? // 驗(yàn)證未通過(guò)，顯示錯(cuò)誤信息

??? out.println( "<a href=index.html> 返回</a>" );

??? } catch (Exception ee){

??? ??? ee.printStackTrace();

??? }

} else {

??? out.println( " 請(qǐng)先登錄！" );? // 驗(yàn)證未通過(guò)，顯示錯(cuò)誤信息

??? out.println( "<a href=index.html> 返回</a>" );

}

%>

</ body >

</ html >

7.?????? 新建 checkvalid.jsp

<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >

< html >

< head >

< title > 驗(yàn)證頁(yè)面 </ title >

</ head >

< body >

<%

??? if (session.getAttribute( "login" )== null || !session.getAttribute( "login" ).equals( "ok" )) {

??????? response.sendRedirect( "index.html" );? // 驗(yàn)證沒(méi)有通過(guò)

??? }??????

%>

</ body >

</ html >

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8.???? 新建main.jsp

<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >

< html >

< head >

< meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" >

< title > 主頁(yè)面 </ title >

</ head >

< body >

<%@ include file = "checkvalid.jsp" %>

??????? 歡迎進(jìn)入本頁(yè)面，您已經(jīng)通過(guò)驗(yàn)證，你的用戶(hù)名是 <%= session.getAttribute( "uname" ) %> < p >

??????? < A HREF = "continue.jsp" > 您可以跳轉(zhuǎn)到后續(xù)頁(yè)面 </ A > ?

</ body >

</ html >

9.???? 新建continue.jsp

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<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %>

<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >

< html >

< head >

< meta http-equiv = "Content-Type" content = "text/html; charsetUTF-8" >

< title > Insert title here </ title >

</ head >

< body >

<%@ include file = "checkvalid.jsp" %>

??????? <%= session.getAttribute( "uname" ) %> , 歡迎您進(jìn)入第二個(gè)頁(yè)面！

</ body >

</ html >

10. 首先在 Eclipse 中啟動(dòng) Tomcat 應(yīng)用服務(wù)器 , 然后啟動(dòng) IE 瀏覽器．

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10.?? 測(cè)試一下 ^_^

先輸入用戶(hù)名，再輸入密碼，當(dāng)然只有在 sql2000 中有的用戶(hù)才是有較用戶(hù)！

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