[英]Wildcards to accept any type with interface
I'm trying to use generics to accept any object that implements the Client
interface, but I can't seem to get it right. 我正在尝试使用泛型来接受任何实现
Client
接口的对象,但我似乎无法做到正确。
public interface Client {
public void makeMove();
}
public MyClient implements Client {
public MyClient(Server server) {
server.connectClient(this);
}
}
The error I get above is: The method connectClient(Class<? extends FanoronaClient>) in the type Server is not applicable for the arguments (GUIClient)
我得到的错误是:
The method connectClient(Class<? extends FanoronaClient>) in the type Server is not applicable for the arguments (GUIClient)
The server with generics: 具有泛型的服务器:
public class Server {
private Class<? extends Client> client_;
public void connectClient(Class<? extends Client> client) {
client_ = client;
client_.makeMove(); // type error here
}
}
And the error here is The method makeMove() is undefined for the type Class<capture#7-of ? extends Client>
这里的错误是
The method makeMove() is undefined for the type Class<capture#7-of ? extends Client>
The method makeMove() is undefined for the type Class<capture#7-of ? extends Client>
What am I doing wrong? 我究竟做错了什么?
You are trying to call a method on the class java.lang.Class
, which doesn't exist. 您正在尝试调用类
java.lang.Class
上的方法,该方法不存在。 What you actually want is an implementation of your class/interface to be passed to your method. 你真正需要的是你的类/接口的实现要传递给你的方法。
Your connetClient
method should look something like this instead: 你的
connetClient
方法看起来应该是这样的:
public void connectClient(Client client) {
client.makeMove(); // no more type error
}
Of course if you want to keep a reference to this in your class, you will have to change the _client
member of your Server
class to also be of type Client
. 当然,如果要在类中保留对此的引用,则必须将
Server
类的_client
成员更改为Client
类型。
I don't think you want to be using generics at all in this example... 在这个例子中,我认为你根本不想使用泛型......
Try this code out : 试试这个代码:
public class Server {
private Class<? extends Client> client_;
public void connectClient(Class<? extends Client> client) {
client_ = client;
client.newInstance().makeMove(); // no error here
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.