Question

我有以下两个Java类（Command和Player）。我希望能够从Command类中列出Player类中的所有公共方法，而不必对它们进行硬编码。我尝试了几种方法，包括接口或命令模式，但我不熟悉Java，我没有设法让它们工作。

在我看来，使用Java的反射API会更容易。但是，当我使用它从Player类打印公共方法时，我得到了无关的方法，我认为这些方法是从Object类继承的。

有没有办法只包含我自己定义的那些方法（即那些以“public method：public void Player。”开头的方法？）？

谢谢，

LC

以下是我得到的输出：

public method: public void Player.search(Command)
public method: public Room Player.getCurrentRoom()
public method: public void Player.engage()
public method: public void Player.trade(Command)
public method: public void Player.goRoom(Command)
public method: public void Player.takeItem(Command)
public method: public void Player.dropItem(Command)
public method: public void Player.lock(Command)
public method: public void Player.unlock(Command)
public method: public final void java.lang.Object.wait(long,int) throws java.lang.InterruptedException
public method: public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException
public method: public final void java.lang.Object.wait() throws java.lang.InterruptedException
public method: public boolean java.lang.Object.equals(java.lang.Object)
public method: public java.lang.String java.lang.Object.toString()
public method: public native int java.lang.Object.hashCode()
public method: public final native java.lang.Class java.lang.Object.getClass()
public method: public final native void java.lang.Object.notify()
public method: public final native void java.lang.Object.notifyAll()

这是Command类：

import java.lang.reflect.Method;

public class Command
{

    // a constant array that holds all valid command words
    private static String[] validCommands;      

    private String commandWord;
    private String secondWord;

    public Command(String firstWord, String secondWord)
    {
        commandWord = firstWord;
        this.secondWord = secondWord;
    }

        [...] //some code omitted

    public boolean process(Player player) 
    {

        Class pClass = player.getClass();
        Method[] methods = pClass.getMethods();
        for (int i = 0; i < methods.length; i++) {
            System.out.println("public method: " + methods[i]);
        }

        boolean wantToQuit = false;

        if(commandWord == null) {
            System.out.println("I don't know what you mean...");
            return false;
        }

        if (commandWord.equals("help")) {
            printHelp();
        }
        else if (commandWord.equals("go")) {
            player.goRoom(this);
        }
        else if (commandWord.equals("quit")) {
            wantToQuit = quit();
        }
        else if (commandWord.equals("take")) {
            player.takeItem(this);
        }
        else if (commandWord.equals("drop")) {
            player.dropItem(this);
        }
        else if (commandWord.equals("search")) {
            player.search(this);
        }
        else if (commandWord.equals("engage")) {
            player.engage();
        }
        else if (commandWord.equals("trade")) {
            player.trade(this);
        }
        else if (commandWord.equals("lock")) {
            player.lock(this);
        }
        else if (commandWord.equals("unlock")) {
            player.unlock(this);
        }
        else {
            System.out.println("Invalid command. Type 'help' if you forgot the list of available commands.");
        }
        // else command not recognised.
        return wantToQuit;
    }
}

以下是Player类的概述：

public class Player
{
    private String name;
    private Room currentRoom;
    private ArrayList<Item> items;

    Player (String name, Room startingRoom)
    {
        this.name = name;
        items = new ArrayList<Item>();
        this.currentRoom = startingRoom;
        printWelcome();
    }

    public void engage()
    {
        [...]
    }

    public void trade(Command command) 
    {
        [...]       }

    public void goRoom(Command command) 
    {   
        [...]       }

    public void search(Command command) 
    {
        [...]       }

    public void takeItem(Command command) 
    {
        [...]       }

    public void dropItem(Command command) 
    {
        [...]       }

    public void lock(Command command)
    {   
        [...]       }

    public void unlock(Command command)
    {   
        [...]
    }

}

Answer 1

您希望使用Java反射API中的getDeclaredMethods（）类。

http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#getDeclaredMethods()

它只为您提供在相关类上声明的方法，忽略超类和接口。

如何列出未继承的方法？

1 个答案: