confirm.java

一个用JSP写的基于了B/S的图书馆管理系统

package web;
/**
 *普通用户登录验证程序
 */
import lms.*;
import java.sql.*;
import java.util.Vector;
import lms.User;

public class Confirm extends DataBase
{
  private String UserID;
  private String Password;
  public Confirm()
  {
    super();
    UserID = "";
    Password = "";
  }
  public String getUserID()
  {
    return this.UserID;
  }
  public void setUserID(String UserID)
  {
    this.UserID = UserID;
  }
  public String getPassword()
  {
    return this.Password;
  }
  public void setPassword(String Password)
  {
    this.Password = Password;
  }
  /*
   如果普通用户与管理员登录一起处理时，用这个方法分别得到两个sql语句;
  public String getSql(){
  }
*/

  /*
  check the UserID and Password when logon
  */
  public boolean execute()
  {
    boolean success = false;
    /*test*/
    String sql="select * from User_table where UserID='"+UserID+"' and UserPassword='"+Password+"'";
    try
    {
      rs = stm.executeQuery(sql);
      if (rs.next())
      {
        UserID = rs.getString("UserID");
        success = true;
      }
      rs.close();
      this.close();
    }
    catch(Exception ex)
    {
     System.out.println(ex);
    }
    finally
    {
      return success;
    }
  }

  /*
  Get the User information
  */
  public Vector information()
  {
    Vector v = new Vector();
    //　用此方法时要保证execute()方法的返回值为true;

    /*
    String sql = "select * from User_table where UserID='"+UserID+"'";

    写程序有好的习惯。。。。。命名一定要注意。。。。。
    */
    //this.UserID = UserID;
    /*

    　rs将为空。。。。。。。切记，　Vector　v 没有值，怪不得后面ElementAt(0)会抛出异常
    　在main.jsp里直接调用setUserID()方法、
   */
    String sql = "select * from User_table where UserID='"+UserID+"'";
    try
    {
      rs = stm.executeQuery(sql);
      if(rs.next()){
        User auser = new User();

        auser.setUserID(rs.getString("UserID"));
        //System.out.println("a");
        auser.setCardID(rs.getString("cardID"));
        //System.out.println("b");
        auser.setIDNumber(rs.getString("IDNumber"));
        //System.out.println("c");

        auser.setUserName(rs.getString("UserName"));

        //System.out.println("d");
        auser.setSex(rs.getString("Sex"));
        //System.out.println("e");
        auser.setAddress(rs.getString("Address"));
        //System.out.println("f");
        auser.setPhone(rs.getString("Phone"));
        //System.out.println("g");
        auser.setEmail(rs.getString("Email"));
        //System.out.println("h");
        auser.setPenalty(rs.getFloat("Penalty"));
        //System.out.println("i");
        auser.setPriority(rs.getInt("Priority"));

        v.addElement(auser);
      }
    }
    catch(Exception ex)
    {
      System.out.println(ex);
      System.out.println("Error: -- Read the table User_table......");
      System.out.println("......error.....");
    }
    return v;
  }

}