基本上，我有一个 libgdx UI，它链接到从 XMLinterpreter 构建的关卡文件。在桌面上，应用程序运行良好。但是当我在手机上运行它时，它找不到 level.xml 文件。是的，它们在 assets 文件夹中，UI 和音乐也在。UI 和音乐都很好用，但是当单击按钮开始关卡时，我得到空指针并且它崩溃了，因为它由于某种奇怪的原因找不到文件。
这是我指定文件路径的代码。Gdx.files.internal 引用 assets 文件夹。在 XMLInterpreter 的构造函数中是实际设置文件路径的位置。下面的代码正是我指定 XMLInterpreter 对象的地方。
public class Level1 extends Level
{
public Level1(Game game)
{
super(game);
}
ObjectCreator oc;
int startX;
int startY;
@Override
protected void createWorld(World world)
{
super.setLevelNum(1);
oc = new ObjectCreator(world);
XMLInterpreter xml = new XMLInterpreter("data/xmlLevels/level 01.xml");
try
{
xml.buildDocument();
}
catch (ParserConfigurationException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (SAXException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
List<Line_xml> lines = xml.iterateLines();
for(Line_xml line : lines){
ObjectType ot = xml.getType(line.type);
oc.createLine(ot, line.x1, line.y1, line.x2, line.y2, line.restitution);
}
List<Square_xml> squares = xml.iterateSquares();
for(Square_xml square : squares)
{
ObjectType ot = xml.getType(square.type);
oc.createBox(ot, square.height, square.width, square.pos_x, square.pos_y, 0);
}
List<Circle_xml> circles = xml.iterateCircles();
for(Circle_xml circle : circles)
{
ObjectType ot = xml.getType(circle.type);
startX = (int) circle.x;
startY = (int) circle.y;
oc.createCircle(ot, circle.radius, circle.x, circle.y, circle.friction, circle.restitution, circle.density);
}
}
下面是 XMLInterpreter buildDocument 方法的代码，它是实际调用来构建文档的方法。我们关注的代码是 buildDocument 方法。那就是文件路径所在的位置：
//Builds document object from factory and prepares for proper reading
//Also assigns the file handle variable
public boolean buildDocument() throws ParserConfigurationException, SAXException
{
try
{
FileHandle fh = Gdx.files.internal(this.filePath);
File xmlF = new File(fh.path());
DocumentBuilderFactory fac = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuild = fac.newDocumentBuilder();
this.doc = dBuild.parse(xmlF);
this.doc.getDocumentElement().normalize();
this.file_handle = fh;
}
catch(IOException io)
{
io.printStackTrace();
return false;
}
}
所有级别 xml 文件都存储在文件路径 assets/data/xmlLevels 中。我相信文件路径指定正确，但 logCat 仍然打印：
08-04 12:22:43.401: WARN/System.err(7980): java.io.FileNotFoundException: /data/xmlFiles/level 01.xml (No such file or directory)
08-04 12:22:43.411: WARN/System.err(7980): at org.apache.harmony.luni.platform.OSFileSystem.open(Native Method)
08-04 12:22:43.411: WARN/System.err(7980): at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:232)
08-04 12:22:43.411: WARN/System.err(7980): at java.io.FileInputStream.<init>(FileInputStream.java:80)
08-04 12:22:43.411: WARN/System.err(7980): at org.apache.harmony.luni.internal.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:82)
08-04 12:22:43.411: WARN/System.err(7980): at org.apache.harmony.xml.parsers.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:120)
08-04 12:22:43.411: WARN/System.err(7980): at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:183)
08-04 12:22:43.411: WARN/System.err(7980): at edu.uab.cis.SMART.Wahball.xml.XMLInterpreter.buildDocument(XMLInterpreter.java:92)
08-04 12:22:43.411: WARN/System.err(7980): at edu.uab.cis.SMART.Wahball.levels.Level1.createWorld(Level1.java:41)
08-04 12:22:43.411: WARN/System.err(7980): at edu.uab.cis.SMART.Wahball.Level.create(Level.java:124)
08-04 12:22:43.411: WARN/System.err(7980): at edu.uab.cis.SMART.Wahball.levels.Level1.render(Level1.java:135)
08-04 12:22:43.421: WARN/System.err(7980): at com.badlogic.gdx.Game.render(Game.java:43)
08-04 12:22:43.421: WARN/System.err(7980): at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:411)
08-04 12:22:43.421: WARN/System.err(7980): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1363)
08-04 12:22:43.421: WARN/System.err(7980): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1118)
08-04 12:22:43.431: WARN/dalvikvm(7980): threadid=9: thread exiting with uncaught exception (group=0x4001d5a0)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): FATAL EXCEPTION: GLThread 14
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): java.lang.NullPointerException
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at edu.uab.cis.SMART.Wahball.xml.XMLInterpreter.iterateLines(XMLInterpreter.java:176)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at edu.uab.cis.SMART.Wahball.levels.Level1.createWorld(Level1.java:54)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at edu.uab.cis.SMART.Wahball.Level.create(Level.java:124)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at edu.uab.cis.SMART.Wahball.levels.Level1.render(Level1.java:135)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at com.badlogic.gdx.Game.render(Game.java:43)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:411)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1363)
08-04 12:22:43.441: ERROR/AndroidRuntime(7980): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1118)
这个问题真正让我困惑的是，该应用程序正在访问 UI 的 uiskin.xml！它恰好在资产文件夹中，并且可以正常访问。两个 xml 文件的文件权限设置完全相同。
任何对此的快速帮助将不胜感激！
如果您需要更多信息，我将很乐意为您服务！