模仿struts:UserManager(业务层)

package com.ankangqiao.servlet;
import java.util.ArrayList;
import java.util.List;
public class UserManager {
public void addUser(String username) {
System.out.println(username + " 添加用户成功");
}
public void deleteUser(String username) {
System.out.println(username + " 已删除");
}
public void modifyUser(String username) {
System.out.println(username + " 已修改");
}
public List queryUser(String username) {
System.out.println(username + " 已查询");
List users = new ArrayList();
users.add("a");
users.add("b");
users.add("c");
return users;
}
}