文件到二维数组打印 null (Java)

Question

我目前正在开发一款游戏，现在（在游戏中）level-editor/reader。我这样做的方法是将级别存储在 txt 文件中，然后将 txt 文件送入 bufferreader，然后将文本文件放入二维数组中，如 [lines][words]。我的意思是我希望第一个方括号中的数字代表您想要的行（来自文件），然后从该行中选择一个单词和另一个方括号。

我开始打印文件并将其存储在一个 class 的二维数组中，但是当我尝试将信息传输到另一个 class 时，如下所示：String strLevel = TextHandler.getLevel("res/levels.txt")
然后当我尝试打印 strLevel[1][1] 时，它只是在控制台中打印出 null...

这是 TextHandler.java 的代码：

public class TextHandler {

final static int LEVELS = Level.LEVEL_AMOUNT;
final static int MAX_LINES = 100;
final static int MAX_WORDS = 100;



public static String[][] getLevel(String path) throws IOException {
    int x = 0;
    int y = 0;

    String lines[][] = new String[MAX_LINES][MAX_WORDS];


    BufferedReader in = new BufferedReader(new FileReader(path));

    String line;

    while ((line = in.readLine()) != null)  //file reading
    {
       String[] values = line.split(" ");

       for (String str : values){   
           lines[x][y] = str;
           System.out.print(lines[x][y] + " ");    //This print funciton works!

           y += 1; 
       }

       x += 1;
       System.out.println("");
    }


    return lines;
}

}

这是文本文件：

level 0
add TYPE_WALL 100 300 400 100
add TYPE_WALL 200 300 200 50
add TYPE_WALL 400 53 800 10
add TYPE_PLAYER 200 40

level 1
add TYPE_WALL 100 300 400 100
add TYPE_WALL 200 300 200 50
add TYPE_WALL 400 53 800 10
add TYPE_PLAYER 100 200

level 2
//Empty level

level 3
//Empty level

level 4
//Empty level

level 5
//Empty level

level 6
//Empty level

这是结果：

level 0
add TYPE_WALL 100 300 400 100
add TYPE_WALL 200 300 200 50
add TYPE_WALL 400 53 800 10
add TYPE_PLAYER 200 40

level 1 add TYPE_WALL 100 300 400 100 add TYPE_WALL 200 300 200 50 add TYPE_WALL 400 53 800 10 add TYPE_PLAYER 100 200

level 2

level 3

level 4

level 5

level 6
null
null
null
null
null
null
null
null
null
null

正如我之前所说，问题是当我尝试制作一个等于 getLevel('path') 的二维数组然后打印它时，它会打印 "null"!!

这是一些级别 class 代码：

套餐com.sontvedt.engine；

进口java.io.IOException；导入 java.util.ArrayList;

导入com.sontvedt.entity.*;

public class 等级 {

Utilities util = new Utilities();
TextHandler txt = new TextHandler();

static final int LEVEL_AMOUNT = 10;

String strLevel[][];

Player player;
Wall wall = new Wall(42,42,42,42);

ArrayList<Entity> objects = new ArrayList<Entity>();
Enemy[] enemies = new Enemy[20];        //This it later going to be added in the entities arrayList. The reason its a normal array is so that it would work with collision detection



//Pre-init of the levelAmount should be done here
public Level(){
    player = new Player(42, 42);

    try {
        strLevel = TextHandler.getLevel("res/levels.txt");
    } catch (IOException e) {
        e.printStackTrace();
    }



    //Init entities ArrayList       
        createLevels(0);

}

//Collision check
public void update(){
}


/*  LEVEL CREATION
 * 
 * The first thing that is going to be in the "level editor" text file
 * is which level the items are going to be added to. Like so:
 *      - level 0
 * 
 * The entity adding is later going to be added in a text file as so:
 *      - Group entity xPos yPos Width Height
 *      - enemies enemy 60 60, 200, 100
 * 
 * The player postition is the first two numbers in txt file,
 * Player is also the last item that should be added to entities
 * 
 * This may have to be in the end of the superloop
 *          
 * for(int i = 0; i < enemies.length; i++)
 *      entities[level].add(enemies[i]);
 * 
 */

public void createLevels(int level){
    objects.add(player);
    objects.add(wall);          

    //Should print add from text file/TextHandler.getLevel()
    System.out.println(strLevel[1][1]);


    for(int i = 0; i >= TextHandler.MAX_LINES; i++){
        for(int j = 0; j >= TextHandler.MAX_WORDS; j++){

            if(strLevel[j][j] == "level"){
                System.out.println("I found the word 'level', I'm so cool, look at meee... :P");
            }
        }
    }   
}

寻找答案已经有一段时间了，但一无所获...请帮忙！

Answer 1

到达新行时您没有重置 y 值：

while ((line = in.readLine()) != null)  //file reading
{
   String[] values = line.split(" ");
   y=0; // gotta start back at 0 when we get to a new line

其他

//Should print add from text file/TextHandler.getLevel()
System.out.println(strLevel[1][1]);

注释不正确，应该打印TYPE_WALL.

if(strLevel[j][j] == "level"){

使用 .equals 而非 == 比较字符串，对于空安全比较，请使用：

if("level".equals(strLevel[j][j]))

if(strLevel[j][j] == "level"){

我很确定你的意思是 strLevel[i][j]，也因为你在其他地方使用了 x 和 y，你应该尽量保持一致。也许将 i 重命名为 x，将 j 重命名为 y。

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