mlogin.java

网络邮件系统

/*
 * This product includes software developed by the
 * Apache Software Foundation (http://www.apache.org/).
 */
package ch05.module;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.*;

import javax.servlet.http.HttpSession;

import ch05.*;

/**
 * 针对登录页面的后台处理类
 * @author ShenYK
 * @version 1.0
 */
public class MLogin
{
    public boolean getUserInfo ( HttpSession mySession, 
    		                       String username, 
    		                       String password )
    {
        //设置用户信息
        Hashtable myValues = (Hashtable)mySession.getAttribute(CommonConst.VIEWID_LOGIN);
        myValues.put("username", username);
        
        //尝试查找用户
        try
        {
            //载入MySQL的JDBC驱动类
            Class.forName(CommonConst.DB_DRIVER_CLASSNAME);
            //获得数据库连接
            Connection conn = DriverManager.getConnection( CommonConst.DB_CONN_STRING );

            Statement stmt = null;
            ResultSet rs = null;
            
            try
            {
                //检查数据库中是否已经有该用户了
                stmt = conn.createStatement();
                //执行SQL语句
                String sQuery = "select realname from user "
                              + "where username='" + username + "' "
                              + "and password='" + password +"'";
                rs = stmt.executeQuery( sQuery );
                if ( rs.next() )
                {
                    mySession.setAttribute("username",username);
                    mySession.setAttribute("realname",rs.getString(1) );
                    return true;
                }
                else
                {
                    mySession.setAttribute("errMsg","用户名密码不正确！");
                    return false;
                }
            }
            catch(Exception e)
            {
                e.printStackTrace();
                mySession.setAttribute("errMsg","登录数据库时出现错误！");
                return false;
            }
            finally
            {
                try
                {
                    rs.close();
                    stmt.close();
                }catch(Exception ex)
                {
                }
            }
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
            mySession.setAttribute("errMsg","登录数据库时出现错误！");
            return false;
        }
        
    }
}