日期:2014-05-18  浏览次数:20819 次

JSP提交验证好难啊
我用的是SQL数据库  
写了一个UserMan.java的文件内容是  

package   kernel;
import   java.sql.*;

public   class   UserMan{
private   String   url= "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=sqldata;user=sa;password=520 ";
public   UserMan(){
try{
Class.forName( "com.microsoft.jdbc.sqlserver.SQLServerDriver ");
}
catch   (Exception   ex){
ex.printStackTrace();
}
}
public   boolean   userExist(String   userID){
Connection   con=null;
PreparedStatement   ps=null;
ResultSet   rs=null;
boolean   exist=true;
try{
con=DriverManager.getConnection(url);
String   selectStr= "select   *   from   userat   where   name=? ";
ps=con.prepareStatement(selectStr);
ps.setString(1,   userID);
rs=ps.executeQuery();
if   (!rs.next())
exist=false;
}
catch(SQLException   exc){
exc.printStackTrace();
}
finally{
if   (rs!=null)   try   {rs.close();}   catch   (SQLException   ignore){}
if   (ps!=null)   try   {ps.close();}   catch   (SQLException   ignore){}
if   (con!=null)   try   {con.close();}   catch   (SQLException   ignore){}
}
return   exist;
}
}

然后建了一个default.htm的文件做为登录提交的,代码是  


<!DOCTYPE   HTML   PUBLIC   "-//W3C//DTD   HTML   4.01   Transitional//EN "
"http://www.w3.org/TR/html4/loose.dtd ">
<html>
<head>
<meta   http-equiv= "Content-Type "   content= "text/html;   charset=gb2312 ">
<title> 无标题文档 </title>
</head>

<body>
<form   name= "form1 "   method= "post "   action= "login.jsp ">
    <input   name= "names "   type= "text "   id= "names ">
    <input   type= "submit "   name= "Submit "   value= "提交 ">
</form>
</body>
</html>

来了个验证login.jsp,代码是
<%@   page   contentType= "text/html;   charset=gb2312 "   language= "java "   import= "java.sql.* "   errorPage= " "   %>
<jsp:useBean   id= "UserMan "     scope= "page "   class= "kernel.UserMan "> </jsp:useBean>

<html>
<head>
<meta   http-equiv= "Content-Type "   content= "text/html;   charset=gb2312 ">
<title> 无标题文档 </title>
</head>

<body>
<%
String   username=request.getParameter( "names ");
if   (!UserMan.userExist(username))
{
out.print( "error!! ");
}
else{
out.print( "ok!!! ");
}
%>
</body>
</html>  

出现错误  

type   Exception   report

message  

description   The   server   encountere