jsp javabean login提示无效 数据库中有 数据库是sqlserver 2008

Question

package org.dao;
import java.sql.*;

import org.model.*;
import org.db.*;
public class LoginDao {
Connection conn;
public Login checkLogin(String name,String password){
try{
conn=DBConn.getConn();

          PreparedStatement pstmt=conn.prepareStatement("select * from _login_ where name=? "+" and password=?");
          pstmt.setString(1,name);
          pstmt.setString(2,password);
          ResultSet rs=pstmt.executeQuery();
          if(rs.next()){
              Login login=new Login();
              login.setId(rs.getInt(1));
              login.setName(rs.getString(2));
              login.setPassword(rs.getString(3));
              login.setRole(rs.getBoolean(4));
              return login;
          }
            return null;


    }catch(Exception e){
        e.printStackTrace();return null;
    }finally{
        DBConn.CloseConn();
    }
}

}

Answer 1

为什么最后返回null呢？ 而且 Login login=new Login();这句 最好先在外部声明，然后在if中再实例化出来