java - 另一个Java事件问题

因此，我在stackoverflow上看到了多个问题，询问如何在Java中实现事件，但似乎没有一个问题提供了其他示例，然后“阅读此内容”。

有人可以请客提供一个简洁的示例，说明如何实现以下C＃代码的基本等效代码吗？

public event EventHandler<MessageReceivedEventArgs> MessageReceived;
protected virtual void OnMessageReceived(Socket socket, CommandType commandType, MemoryStream message)
{
    if (this.MessageReceived != null)
    {
        this.MessageReceived(this, new MessageReceivedEventArgs(socket, commandType, message));
    }
}

最佳答案

通常，Java中不使用多播委托。如果您不需要多播，那么代码将如下所示：

public interface MessageReceivedListener {
    void onMessageReceived(Object sender, MessageReceivedEventArgs e);
}

private MessageReceivedListener messageReceivedListener;

public void setMessageReceivedListener(MessageReceivedListener listener) {
    this.messageReceivedListener = listener;
}

protected void onMessageReceived(Socket socket, CommandType commandType, MemoryStream message) {
    if (this.messageReceivedListener != null) {
        this.messageReceivedListener.onMessageReceived(this,
           new MessageReceivedEventArgs(socket, commandType, message));
    }
}

如果要实现多播，则可以创建带有侦听器的容器，并遍历这些侦听器和调用处理程序。在这种情况下，将存在用于管理活动侦听器的addMessageReceivedListener和removeMessageReceivedListener方法。