问题：当骨架进入一个地方时，我希望在我的World对象中使用此方法更新所有玩家屏幕：
/**
* Say `text' in the Place `place'. The text will become visible at the
* bottom of the text window of any Players currently watching `place'.
*
* @param place
* The place where the string will be displayed.
* @param text
* The string to be diplayed.
*/
public void sayAtPlace(Place place, String text) {
synchronized (players) {
Iterator<Player> ls = players.iterator();
while (ls.hasNext()) {
Player p = ls.next();
if (p.currentPlace() == place) {
p.say(text);
}
}
}
}
我有两个类，Person 和 Player，我希望 Person 在goTo调用该方法时写入 textarea，但我无法使 Person 对象正确引用具有 textarea 的 Player：
package adventure;
import java.awt.*;
import java.util.*;
/**
* ADT for persons which is completed which subclasses to creating actors with
* specific properties
*/
public class Person {
public Player player = null;
/**
* Name of the Person.
*/
public String name;
/**
* The World which this Person is associated with.
*/
public World world;
/**
* Tells where this Person is at the moment.
*/
public Place where;
/**
* Create Person named `name' in world `world'.
*
* @param world
* The world where the Person is created.
* @param name
* Name of the Person.
* @param app
* An image used to display the Person.
*/
public Person(World world, String name, Image app) {
this.world = world;
this.name = name;
this.appearance = app;
// this.player = player;
where = world.defaultPlace();
where.enter(this);
inventory = Collections.synchronizedCollection(new LinkedList<Thing>());
}
/**
* Go directly, and quietly, to 'place'. That is to say, without posting a
* message that you're doing so.
*
* @param place
* A string referring to the Place to go to.
* @see #goTo(Place)
* @see #go
*/
public void goTo(String place) {
goTo(world.getPlace(place), null);
}
/**
* Go directly, and quietly, to `whereTo'. That is to say, without posting a
* message that you're doing so.
*
* @param whereTo
* The Place to go to. Can be null in which case nothing happens.
* @see #goTo(String)
* @see #go
*/
public void goTo(Place whereTo, Player player) {
if (whereTo != null) {
where.exit(this);
whereTo.enter(this);
// Update any Player's which are viewing place `where'.
world.update(where);
// Record our new position.
where = whereTo;
// Also update Player's here.
world.update(where);
}
System.out.println("player:"+player);
if(player != null){
player.say("A terrifying skeleton warrior appears!");
}
// send a msg which doors are available
Object[] doorNames = whereTo.exits.keySet().toArray();
String s = "";
int i = 1;
for (Object obj : doorNames) {
if (i < doorNames.length) {
s = s + obj.toString().toLowerCase();
if(i<doorNames.length){
s = s+ ",";
}
} if (i == doorNames.length && i > 1) {
s = s + " and " + obj.toString().toLowerCase();
}
if (i == doorNames.length && i == 1) {
s = obj.toString().toLowerCase();
}
++i;
}
if (player != null) {
player.say("There are doors " + s);
}
}
package adventure;
import java.awt.*;
/**
* A Player object enables commands to control a certain person: »you». This
* object is displayed graphically as a control panel where the user both can
* control and follow the course of events
*/
public class Player extends Panel {
private Person me;
private PlaceView placeview;
private Commands commands;
private TextArea textarea;
private static final long serialVersionUID = 100L;
/**
* Creates a new instance of Player, in World w, reflecting Person p.
*
* @param w
* The world in which the Player will play in.
* @param p
* The Person associated by Player.
*/
Player(World w, Person p) {
setLayout(new BorderLayout());
setSize(650, 540);
me = p;
p.player = this;
placeview = new PlaceView(me);
commands = new Commands(me);
textarea = new TextArea("", 10, 60, TextArea.SCROLLBARS_VERTICAL_ONLY);
textarea.append("You are in a dungeon. The horrible shrieks of the undead chill your bones.\n");
textarea.setEditable(false);
add("West", placeview);
add("East", commands);
add("South", textarea);
w.addPlayer(this);
}
/**
* Display a string in the players graphical interface.
*
* @param text
* A string to display.
*/
void say(String text) {
textarea.append(text + '\n');
textarea.repaint();
}
/**
* Returns the Place of the Person associated with the Player.
*
* @return The Place of the Person associated with the Player.
*/
public Place currentPlace() {
return me.where;
}
}
你明白我想要做什么吗？我想要工作的代码是
System.out.println("player:"+player);
if(player != null && this.name.equals("Skeleton")){
player.say("A terrifying skeleton warrior appears!");
}
但是没有实例化作为僵尸的 Person 的玩家引用。唯一实例化了 Player 对象的 Person 是也是 Person 的 Player。
你能帮助我吗？我还在此处发布了 Person、Player 和 World 类的完整版本
http://pastebin.com/RJCcr2ph (人) http://pastebin.com/eYSh8L9Q (播放器) http://pastebin.com/DKvRvEY8 (世界)