B/S登陆例子（JSP+JavaBean+MYSQL）
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<display-name>jspLogin</display-name>
</web-app>
index.jsp
<%
if(session.getAttribute("passed")==null){
response.sendRedirect("login.jsp");
return;
}
%>
passed!
login.jsp
<%@ page contentType="text/html; charset=utf-8" %>
<html>
<head>
<title>
login
</title>
</head>
<body bgcolor="#ffffff">
<%
String flag=request.getParameter("flag");
if(flag!=null&&flag.equals("0")){
out.println("Pls input valid username and password!<br><br>");
}
%>
<form name="form1" method="post" action="loginSuccess.jsp">
<input name="username" type="text"><br/>
<input name="password" type="password"><br/>
<input name="reset" type="reset" value="reset">
<input name="submit" type="submit" value="submit">
</form>
</body>
</html>
loginSuccess.jsp
<%@ page import="test.LoginCheck"%>
<%
String username=request.getParameter("username");
String password=request.getParameter("password");
boolean flag=false;
LoginCheck lc=new LoginCheck();
if(lc.check(username,password)){
flag = true ;
out.print("passed!");
}else{
out.print("failed!");
}
if(flag){
session.setAttribute("passed","true");
response.sendRedirect("index.jsp");
}else{
response.sendRedirect("login.jsp?flag=0");
}
%>
LoginCheck.java
package
test;
import
java.sql.
*
;
public
class
LoginCheck
...
{
public static boolean check(String username,String password) ...{
boolean flag = false; try ...{ String sql = "select * from user where username='" + username + "' and password='" + password + "'";// Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection( "jdbc:mysql://localhost:3306/test?user=cwb&password=cwb123&useUnicode=true"); Statement pstmt = conn.prepareStatement(sql); ResultSet rs = pstmt.executeQuery(sql); if (rs.next()) ...{ flag = true;
}// rs.close(); pstmt.close(); conn.close(); }catch(Exception ex)...{ ex.printStackTrace(); } return flag; }
}