通过类路径上的安全镜像，你可以得到类似c#委托和事件的东西。

来自项目README的例子:

Java中的委托!

  Delegate.With1Param<String, String> greetingsDelegate = new Delegate.With1Param<>();
  greetingsDelegate.add(str -> "Hello " + str);
  greetingsDelegate.add(str -> "Goodbye " + str);

  DelegateInvocationResult<String> invocationResult = 
  greetingsDelegate.invokeAndAggregateExceptions("Sir");

  invocationResult.getFunctionInvocationResults().forEach(funInvRes -> 

  System.out.println(funInvRes.getResult()));
  //prints: "Hello sir" and "Goodbye Sir"

事件

  //Create a private Delegate. Make sure it is private so only *you* can invoke it.
  private static Delegate.With0Params<String> trimDelegate = new Delegate.With0Params<>();

  //Create a public Event using the delegate you just created.
  public static Event.With0Params<String> trimEvent= new Event.With0Params<>(trimDelegate)

看看这个SO的答案。

我知道这篇文章很旧了，但是Java 8增加了lambdas和函数接口的概念，即任何接口都只有一个方法。它们一起提供了与c#委托类似的功能。查看这里获得更多信息，或者只是谷歌Java Lambdas。 http://cr.openjdk.java.net/~briangoetz/lambda/lambda-state-final.html

简短的故事:没有。

Introduction The newest version of the Microsoft Visual J++ development environment supports a language construct called delegates or bound method references. This construct, and the new keywords delegate and multicast introduced to support it, are not a part of the JavaTM programming language, which is specified by the Java Language Specification and amended by the Inner Classes Specification included in the documentation for the JDKTM 1.1 software. It is unlikely that the Java programming language will ever include this construct. Sun already carefully considered adopting it in 1996, to the extent of building and discarding working prototypes. Our conclusion was that bound method references are unnecessary and detrimental to the language. This decision was made in consultation with Borland International, who had previous experience with bound method references in Delphi Object Pascal. We believe bound method references are unnecessary because another design alternative, inner classes, provides equal or superior functionality. In particular, inner classes fully support the requirements of user-interface event handling, and have been used to implement a user-interface API at least as comprehensive as the Windows Foundation Classes. We believe bound method references are harmful because they detract from the simplicity of the Java programming language and the pervasively object-oriented character of the APIs. Bound method references also introduce irregularity into the language syntax and scoping rules. Finally, they dilute the investment in VM technologies because VMs are required to handle additional and disparate types of references and method linkage efficiently.

你读过这篇文章吗?

Delegates are a useful construct in event-based systems. Essentially Delegates are objects that encode a method dispatch on a specified object. This document shows how java inner classes provide a more generic solution to such problems. What is a Delegate? Really it is very similar to a pointer to member function as used in C++. But a delegate contains the target object alongwith the method to be invoked. Ideally it would be nice to be able to say: obj.registerHandler(ano.methodOne); ..and that the method methodOne would be called on ano when some specific event was received. This is what the Delegate structure achieves. Java Inner Classes It has been argued that Java provides this functionality via anonymous inner classes and thus does not need the additional Delegate construct.

obj.registerHandler(new Handler() {
        public void handleIt(Event ev) {
            methodOne(ev);
        }
      } );

At first glance this seems correct but at the same time a nuisance. Because for many event processing examples the simplicity of the Delegates syntax is very attractive. General Handler However, if event-based programming is used in a more pervasive manner, say, for example, as a part of a general asynchronous programming environment, there is more at stake. In such a general situation, it is not sufficient to include only the target method and target object instance. In general there may be other parameters required, that are determined within the context when the event handler is registered. In this more general situation, the java approach can provide a very elegant solution, particularly when combined with use of final variables:

void processState(final T1 p1, final T2 dispatch) { 
  final int a1 = someCalculation();

  m_obj.registerHandler(new Handler() {
    public void handleIt(Event ev) {
     dispatch.methodOne(a1, ev, p1);
    }
  } );
}

final * final * final Got your attention? Note that the final variables are accessible from within the anonymous class method definitions. Be sure to study this code carefully to understand the ramifications. This is potentially a very powerful technique. For example, it can be used to good effect when registering handlers in MiniDOM and in more general situations. By contrast, the Delegate construct does not provide a solution for this more general requirement, and as such should be rejected as an idiom on which designs can be based.

所描述的代码提供了c#委托的许多优点。方法，无论是静态的还是动态的，都可以以统一的方式处理。通过反射调用方法的复杂性降低了，而且代码是可重用的，因为在用户代码中不需要额外的类。请注意，我们调用的是invoke的另一个方便版本，其中只带一个参数的方法可以在不创建对象数组的情况下被调用。

  class Class1 {
        public void show(String s) { System.out.println(s); }
    }

    class Class2 {
        public void display(String s) { System.out.println(s); }
    }

    // allows static method as well
    class Class3 {
        public static void staticDisplay(String s) { System.out.println(s); }
    }

    public class TestDelegate  {
        public static final Class[] OUTPUT_ARGS = { String.class };
        public final Delegator DO_SHOW = new Delegator(OUTPUT_ARGS,Void.TYPE);

        public void main(String[] args)  {
            Delegate[] items = new Delegate[3];

            items[0] = DO_SHOW .build(new Class1(),"show,);
            items[1] = DO_SHOW.build (new Class2(),"display");
            items[2] = DO_SHOW.build(Class3.class, "staticDisplay");

            for(int i = 0; i < items.length; i++) {
                items[i].invoke("Hello World");
            }
        }
    }

是或否，但是Java中的委托模式可以这样考虑。本视频教程讲的是活动片段之间的数据交换，具有使用接口的委托排序模式的精髓。