jsp代码实例第255课

code255.java

package pack07;

import java.util.HashMap;

//模拟DBUtil类
public class code255
{
  private static code255 instance = new code255(); //实例一次

  //模拟数据库
  private HashMap<String, code253> users = new HashMap<>();

  private code255()
  {
    //向数据库中加入数据
    code253 user1 = new code253(); //UserBean
    user1.setName("Jack");
    user1.setPwd("123");
    user1.setEmail("jack@163.com");
    users.put("Jack", user1);

    code253 user2 = new code253();
    user2.setName("Rose");
    user2.setPwd("456");
    user2.setEmail("rose@qq.com");
    users.put("Rose", user2);
  }

  public static code255 getInstance()
  {
    return code255.instance;
  }

  public code253 getUser(String userName)
  {
    code253 user = (code253)users.get(userName); //UserBean
    return user;
  }

  public boolean insertUser(code253 user)
  {
    if (user == null)
    {
      return false;
    }

    String userName = user.getName();
    if (users.get(userName) != null)
    {
      return false;
    }
    users.put(userName, user);
    return true;
  }


}