英文:
How to make a class accept different type of child classes (of another parent class) in the constructor in java
问题
我目前在努力解决这个问题，所以请对我温柔一点，因为我对这一切还很陌生。
我有一个名为Player的类，其中一个参数是Location。然而，现在我遇到了一个问题，我不太确定如何解决。我创建了多个Location的子类，比如HotelRoom和HotelKitchen，我需要能够从创建的Player对象中访问子类中的方法。
现在，我不能只是更改Player的构造函数以接受HotelRoom，因为角色的位置可能会改变为HotelKitchen。
Player类：
...
Location类：
...
一个Location的子类示例：
...
以下是我的ApplicationTester类（其中包含main方法）中的一个方法，用于创建一个位置对象，然后将其设置为参数：
...
allItems（number）方法用于上面的方法：
...
现在我看到有些人建议使用接口/抽象类，感谢您的建议，但出于两个原因我还是有些困惑。
首先，main中的setLocation方法只能返回一个位置，现在一旦位置被设置为抽象类，它是否允许我返回任何Location的子类？
最后，与上面类似的情况。如果位置被设置为抽象类，Player的构造函数是否接受Location的任何子类？
英文:
I am struggling a lot with this so do go easy on me please as I am still new to all of this.
I have a class called Player and one of the parameters it takes is a Location. However, I have now run into a issue which I am not to sure how to solve. I have made multiple child classes of Location, like HotelRoom and HotelKitchen, and I need to be able to access the methods in the child classes from the a created Player object .
Now I can not just change the Player's constructor to accept HotelRoom as the characters location might change to HotelKitchen.
Player Class:
public class Player {
private int health;
private int cluesLeft; //1 clue per level
private String name;
private Location currentRoom;
public Player(String name, int health, int cluesLeft, Location currentRoom) {
this.setHealth(health);
this.setCluesLeft(cluesLeft);
this.setName(name);
this.setCurrentRoom(currentRoom);
}
/**
* @return the health
*/
public int getHealth() {
return health;
}
/**
* @param health the health to set
*/
public void setHealth(int health) {
this.health = health;
}
/**
* @return the cluesLeft
*/
public int getCluesLeft() {
return cluesLeft;
}
/**
* @param cluesLeft the cluesLeft to set
*/
public void setCluesLeft(int cluesLeft) {
this.cluesLeft = cluesLeft;
}
/**
* @return the name
*/
public String getName() {
return name;
}
/**
* @param name the name to set
*/
public void setName(String name) {
this.name = name;
}
/**
* @return the currentRoom
*/
public Location getCurrentRoom() {
return currentRoom;
}
/**
* @param currentRoom the currentRoom to set
*/
public void setCurrentRoom(Location currentRoom) {
this.currentRoom = currentRoom;
}
}
Location Class
import java.util.Scanner;
/**
*
* @author User
*/
public class Location {
static Scanner scan = new Scanner(System.in);
private String locationImage; // string holds the ASCII map
private String locationName;
private String[] itemImages;
public Location(String locationName, String locationImage, String[] itemImages) {
this.setLocationName(locationName);
this.setLocationImage(locationImage);
this.setItemImages(itemImages);
}
/**
* @return the locationImage
*/
public String getLocationImage() {
return locationImage;
}
/**
* @param locationImage the locationImage to set
*/
public void setLocationImage(String locationImage) {
this.locationImage = locationImage;
}
/**
* @return the locationName
*/
public String getLocationName() {
return locationName;
}
/**
* @param locationName the locationName to set
*/
public void setLocationName(String locationName) {
this.locationName = locationName;
}
public void printLocationMap() {
try {
Thread.sleep(1500);
} catch (Exception e) {
System.out.print(e);
}
System.out.println(this.getLocationImage());
}
public String retrieveSpecificItem(int item){
String[] array = this.getItemImages();
for (int x = 0; x < array.length; x++) {
if (item == (x + 1)) {
return array[x];
}
else {
return null;
}
}
return null;
}
/**
* @return the itemImages
*/
public String[] getItemImages() {
return itemImages;
}
/**
* @param itemImages the itemImages to set
*/
public void setItemImages(String[] itemImages) {
this.itemImages = itemImages;
}
One of locations child classes
import java.util.Scanner;
/**
*
* @author User
*/
public class HotelRoom extends Location {
Scanner scan = new Scanner(System.in);
public HotelRoom(String locationName, String locationImage, String[] itemImages) {
super(locationName, locationImage, itemImages);
}
public static String instructions(Player gameCharacter) {
boolean loopDone = false;
String choice = "";
do {
String menu = "What would you like to do next?\n"+
"1.) Move to Kitchen\n"+
"2.) Inspect PC\n"+
"3.) Inspect Cupboard\n"+
"4.) Inspect bed\n"
+ "5.) Guess who did it!";
int userChoice = JavaApplication2.checkInput(menu);
switch(userChoice) {
case 1:
choice = "HotelKitchen";
loopDone = true;
break;
case 2:
System.out.println(this.retrieveSpecificItem(0));
break;
case 3:
System.out.println(this.retrieveSpecificItem(1));
break;
case 4:
System.out.println(this.retrieveSpecificItem(2));
break;
case 5:
choice = "Choose";
break;
}
}while (loopDone == false);
return choice;
}
}
Below is a method in my ApplicationTester class (which has the main) that creates a location object to then set as a paramater
public static Location setLocations(int whichRoom) {
Location locations = null;
String room = ("|----------| [1] |----------|\n"+
"| [CUPBOARD] [PC] |\n"+
"| P |\n"+
"| |\n"+
"| [BED] |\n"+
"| | | |\n"+
"| | X | |\n"+
"| |___| |\n"+
"|-------------------------------|\n");
String kitchen = ("|----------| [1] |----------|\n"+
"| [FRIDGE] [OVEN] |\n"+
"| P |\n"+
"| |\n"+
"| [SERVING TABLE] |\n"+
"| |\n"+
"| [TABLES] |\n"+
"| |\n"+
"|-------------------------------|\n");
if (whichRoom == 1) {
Location hotelRoom = new Location("Hotel Room", room, allItems(1));
locations = hotelRoom;
}
else {
Location hotelKitchen = new Location("Hotel Kitchen", kitchen, allItems(2));
locations = hotelKitchen;
}
return locations;
}
The allitems(number) method which is used by the method above
public static String[] allItems(int area) {
String pc = "\n" +
" ____________________________________________________\n" +
" / \\\n" +
" | _____________________________________________ |\n" +
" | | ___________________ | |\n" +
" | | | | | |\n" +
" | | DuckDuckGo - |How to remove stain| | |\n" +
" | | |___________________| | |\n" +
" | | | |\n" +
" | | | |\n" +
" | | | |\n" +
" | | Removing stains from any surface | |\n" +
" | | | |\n" +
" | | Getting rid of stains in 3 steps | |\n" +
" | | | |\n" +
" | | Choosing the right stain remover | |\n" +
" | | | |\n" +
" | |_____________________________________________| |\n" +
" | |\n" +
" \\\\_____________________________________________________/\n" +
" \\\\_______________________________________/\n" +
" _______________________________________________\n" +
" _-' .-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-. --- `-_\n" +
" _-'.-.-. .---.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.--. .-.-.`-_\n" +
" _-'.-.-.-. .---.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-`__`. .-.-.-.`-_\n" +
" _-'.-.-.-.-. .-----.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-----. .-.-.-.-.`-_\n" +
" _-'.-.-.-.-.-. .---.-. .-----------------------------. .-.---. .---.-.-.-.`-_\n" +
":-----------------------------------------------------------------------------\n" +
"`---._.-----------------------------------------------------------------._.---";
String cupboard = " __________\n" +
" / /|\n" +
" /__________/ |\n" +
" |________ | |\n" +
" /_____ /|| |\n" +
"|\".___.\"| || |\n" +
"|_______|/ | |\n" +
" || .___.\"|| /\n" +
" ||_______|| /\n" +
" |_________|/\n";
String bed = " __.--'|\n" +
" ___.---' |\n" +
" ___.---' |\n" +
" _.--' \\\\\\ |\n" +
" | XX | |\n" +
" | U. ' |\n" +
" J __=__ |\n" +
" L / |\n" +
" L / /|. .| -`-.\n" +
" | | ||____| __.>-._\n" +
" | | || |__.--' `--._\n" +
" J-._ _____.---------' `--.__\n" +
" J `-<_ `-.__\n" +
" L `-. _>-.\n" +
" +. `-._ ___.--' |\n" +
" | `-._ `-._ __.--' |\n" +
" `-._ `-. __.--' _.--'\n" +
" `-._ `-._.-' _.--' |\n" +
" `-. | _.--'\n" +
" `-. | _.--'\n" +
" `-. | _.--'\n" +
" `|'\n" +
" |";
String sink = " ___\n" +
" .' _ '.\n" +
" / /` `\\ \\\n" +
" | | [__]\n" +
" | | {{\n" +
" | | }}\n" +
" _ | | _ {{\n" +
" ___________<_>_| |_<_>}}________\n" +
" .=======^=(___)=^={{====.\n" +
" / .----------------}}---. \\\n" +
" / / {{ \\ \\\n" +
" / / }} \\ \\\n" +
" ( '=========================' )\n" +
" '-----------------------------'";
String couch = ".----.\n" +
" | |\n" +
" |____|\n" +
" _.-------------._()_.-------------._\n" +
" / | | )( | | \\\n" +
" | | | () | | |\n" +
" _\\|_____________| )( |_____________|/_\n" +
".=. / /(__)\\ \\ .=.\n" +
"|U|/_____________/______\\_____________\\|U|\n" +
"| |====================================| |\n" +
"| | | |\n" +
"|_|LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLlc|_|";
String bin = " _.,-----/=\\-----,._\n" +
" (__ ~~~\"\"\"\"\"\"\"~~~ __)\n" +
" | ~~~\"\"\"\"\"\"\"\"\"~~~ |\n" +
" | | ; , , ; | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" | | | | | | | |\n" +
" |. \\_| | | |_/ .|\n" +
" `-,.__ ~~~ __.,-'\n" +
" ~~~~~";
String[] hotelRoom = {pc, cupboard, bed};
String[] hotelKitchen = {bin, couch, sink};
if (area == 1) {
return hotelRoom;
} else if (area == 2) {
return hotelKitchen;
} else if (area == 3) {
return null; //not set up yet
} else if (area == 4){
return null; //not set up yet
} else {
return null; //not set up yet
}
}
Now I see some people are suggesting interfaces/abstract classes and I thank you for the input but still confused for two reasons.
Firstly, the method in main called setLocation can only return a location, now once location is made Abstract will it allow me to return any class that is a child of location?
Lastly, similar situation as above. If location is made Abstract, would the Player constructor accept any child class of location?
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