usermanager.java

描述工厂管理多个工人 工厂类 属性：工厂名称 行为：添加 删除工人 工人类 属性：姓名 （1）使用数组装载工人对象

class UserManager{
   User users[];
   int length;
   int index;
   public UserManager(int a){
      users=new User[a];
      index=0;	
   }
   public User[] getUsers(){
   	 return this.users;
   	}
   public void add(User u){
   if(!PrivilegeConfig.privilege.equals("user")){
   	  if(users.length-1<index){
      users=extend();
      add(u);
     }
     users[index++]=u;
     }else{
     	System.out.println("you are user,you have no privilege to add a user");
     	}	
   }
   public void add(String username){
   	if(!PrivilegeConfig.privilege.equals("user")){
      if(users.length-1<index){
      users=extend();
      User u=new User(username);
      add(u);
     }
      User u=new User(username);
      users[index++]=u;
      }else{
     	System.out.println("you are user,you have no privilege to add a user");
     	}           	
   }
   private User[] extend(){
     length=2*length;
     User extendU[]=new User[length];
     for(int i=0;i<index;i++)
     extendU[i]=users[i];
     return extendU;	
   }
   public User get(String username) throws Exception{
     for(int i=0;i<index;i++){
        User temp=users[i];
        String name=temp.getUserName();
        if(name.equals(username))
           return temp;	
     }
     throw new Exception("user : "+username +" not be found");	
   }
   public void delUser(String u) throws Exception{
   	if(!PrivilegeConfig.privilege.equals("user")){
      for(int i=0;i<index;i++){
      	String temp=users[i].getUserName();
      	System.out.println(temp);
      	if(temp.trim().equals(u)){
      	   users[i]=null;
      	   for(int j=i+1;j<index;j++){
      	     users[i]=users[j]; 
      	   }
      	   index=index-1;
      	   return;	
      	}
      	}
      	throw new Exception("no User be found!");
      }else{
     	System.out.println("you are user,you have no privilege to add a user");
     	}   	
   }
   
   public static void main(String a[]){
   	  PrivilegeConfig.privilege="admin";
   	  UserManager um=new UserManager(10);
   	  um.add("th");
   	  um.add("yj");
   	  try{
   	  um.delUser("th"); 
   	  }catch(Exception e){
   	  	System.out.println(e.getMessage());
   	  	}
   	  System.out.println(um.index);
   	}	
}