Java方法容器

Question

我试图在Java中实现一个动作/反应系统。
为此，我需要将所有方法存放在容器中，以便我可以轻松地调用所需的响应，并返回所需的操作。
作为一名C++开发人员和Java新手，我的第一个直觉就是创建一个函数指针数组（至少重现它），所以我尝试使用匿名子类。但没有得到我期待的结果。
所以我尝试使用lambdas，这里是我想要做的一个示例。

public class Test { 
     public Map<Integer, Vector<String>> actions = new HashMap<>(); 
     public Map<Integer, Integer> responses = new HashMap<>(); 

     public Test() { 
     Vector<String> v= new Vector<String>(); 

     actions.put(0, action0()); 
     actions.put(1, action1()); 
     responses.put(0, response0(Vector<String>)); // How can I leave aside this argument which I don't know at this point ? 
     responses.put(1, response1(Vector<String>)); 
     } 

     public Vector<String> action0() {...} 
     public Vector<String> action1() {...} 

     // This methods takes actions return as argument 
     public Integer response0 (Vector<String>) {...} 
     public Integer response1 (Vector<String>) {...} 

     public void run() { 
     // When I run, I want to be able to launch any of my responses with any of my actions return 
     responses.get(0) 
     } 
    } 

我至少试过一个很好的方法来解决这个问题吗？
非常感谢

Answer 1

代码有一些缺陷，所以我会假设 getHashtag()和 action1()都应该是一样的，和类似的其他三个。

另外，我假设第二 responses.put()应该是关键 1，不 0。 另外，您的responseX()方法的参数需要一个名称。

无论如何，你需要一个功能接口，所以你可以给responseX()方法Method References。

对于您的情况，responseX()方法采用Vector<String>作为参数，并返回Integer，因此功能接口将为Function<Vector<String>, Integer>。

然后，您可以构建这些方法的映射，稍后执行。

public Test() { 
    // Here we can build map of response methods first, if we like, even though Vectors don't exist yet 
    Map<Integer, Function<Vector<String>, Integer>> responseMethods = new HashMap<>(); 
    responseMethods.put(0, this::response0); 
    responseMethods.put(1, this::response1); 

    // Now we build the action map of Vectors 
    Map<Integer, Vector<String>> actions = new HashMap<>(); 
    actions.put(0, action0()); 
    actions.put(1, action1()); 

    // At this time, we can now execute the referenced methods to get the actual responses 
    Map<Integer, Integer> responses = new HashMap<>(); 
    for (Integer key : actions.keySet()) { 
     Vector<String> v = actions.get(key); 
     Function<Vector<String>, Integer> responseMethod = responseMethods.get(key); 
     Integer response = responseMethod.apply(v); 
     responses.put(key, response); 
    } 
} 

public Vector<String> action0() {...} 
public Vector<String> action1() {...} 

public Integer response0(Vector<String> v) {...} 
public Integer response1(Vector<String> v) {...} 

，如果你愿意，你甚至可以推迟的行动方法的执行：

public Test() { 
    // Here we can build map of response methods first, if we like, even though Vectors don't exist yet 
    Map<Integer, Function<Vector<String>, Integer>> responseMethods = new HashMap<>(); 
    responseMethods.put(0, this::response0); 
    responseMethods.put(1, this::response1); 

    // Now we build the action map of Vectors 
    Map<Integer, Supplier<Vector<String>>> actionMethods = new HashMap<>(); 
    actionMethods.put(0, this::action0); 
    actionMethods.put(1, this::action1); 

    // At this time, we can now execute the referenced methods to get the actual responses 
    Map<Integer, Integer> responses = new HashMap<>(); 
    for (Integer key : actionMethods.keySet()) { 
     Supplier<Vector<String>> actionMethod = actionMethods.get(key); 
     Function<Vector<String>, Integer> responseMethod = responseMethods.get(key); 
     Vector<String> v = actionMethod.get(); 
     Integer response = responseMethod.apply(v); 
     responses.put(key, response); 
    } 
}