java - 如何解决此未经检查的强制转换警告？

Question

这一行给了我未经检查的强制转换警告

this.gameSocket = (U) game.getGameSocket();

SocketHandler.java:

public class SocketHandler<T extends Game, U extends GameSocket> extends 
Listener
{
    protected T game;
    protected U gameSocket;

    public SocketHandler(T game)
    {
        this.game = game;
        this.gameSocket = (U) game.getGameSocket();
    }
}

游戏.java:

public class Game<T extends GameSocket>
{
    protected T gameSocket;

    public T getGameSocket()
    {
        return gameSocket;
    }

    public Game()
    {

    }
}

GameSocket.java:

public class GameSocket<T extends Game>
{
    protected T game;
    protected int port;

    public GameSocket(T game, int port)
    {
        this.game = game;
        this.port = port;
    }
}

我觉得这里好像存在一般的循环问题，但代码工作正常。然而，可能有更好的方法来完成我在这里所做的事情。

Answer 1

您有一个通用循环:GameSocket 的通用类型扩展了 Game，但 Game 的通用类型扩展了 GameSocket!

要解决此问题，我建议将 GameSocket 的类声明更改为:

public class GameSocket<T> {
    ...
}

然后，您可以将 Game 的类声明更改为:

public class Game<T extends GameSocket<T>> {
    ...
}

最后，您可以将 SocketHandler 的类声明更改为:

public class SocketHandler<T extends Game<U>, U extends GameSocket<U>> extends Listener {
    ...
}

这使得所有内容都是类型安全的并且警告消失了。

您甚至可以在检索 game.getGameSocket() 时删除显式转换 (U)