<%@ page contentType="text/html; charset=Windows-31J" %>
<%@ page import="fsearch.*" %>
<jsp:useBean class="fsearch.User" id="user" scope="session"/>
<%
String stUserName = request.getParameter("userName");
String stPassword = request.getParameter("userPass");

boolean blResult = user.login(stUserName,stPassword);
if(blResult){
%>
    <jsp:forward page="manage.jsp" />    //trueの場合の転送先
<% }else{ %>
    <jsp:forward page="login_error.jsp" />    //falseの時の転送先
<% } %>

package fsearch;

import java.sql.*;
import java.util.*;
import javax.sql.*;
import javax.naming.*;

public class User{

//ユーザ名とパスワードの照合
    public boolean login(String stUserName, String stPassword) throws Exception{
        boolean blResult;
        Context context = new InitialContext();
        DataSource ds = (DataSource)context.lookup("java:comp/env/jdbc/Jsp10");
        Connection conn = ds.getConnection();
        PreparedStatement ps = conn.prepareStatement
            ("SELECT * FROM user WHERE userName =? AND userPass =?");
            ps.setString(1, stUserName);
            ps.setString(2, stPassword);
        ResultSet rs = ps.executeQuery();
        if(rs.next()){
            blResult = true;
        }else{
            blResult = false;
        }
        return blResult;
    }
}