I am making a 2D game in Android with Cocos2D, written in Java. Here is my code for the main stuff:
public void gameLoop(float dt) {
//Player Gravity
if(canExecuteMovement(0, 6)) {
guy.moveY(6);
}
//Player Movement
if(direction == 1) {
if(canExecuteMovement(-3, 0))
guy.moveX(-3);
} else if(direction == 2) {
if(canExecuteMovement(3, 0))
guy.moveX(3);
}
}
private boolean canExecuteMovement(int xChange, int yChange) {
int projectedX = guy.getBounds().left + xChange;
int projectedY = guy.getBounds().top + yChange;
Log.i("DD", "guy:" + guy.getBounds().toString());
Rect projectedBounds = new Rect(projectedX, projectedY, projectedX + guy.getWidth(), projectedY + guy.getHeight());
Log.i("DD", "guy:" + projectedBounds.toString());
for (int i = 0; i < platformCount; i++) {
if (Rect.intersects(projectedBounds, platform[i].getBounds())) {
return false;
}
}
return true;
}
As you see, this function looks just fine, and the rectangles in canExecuteMovement are perfectly fine too, however in this line:
LINE 107: if (Rect.intersects(projectedBounds, platform[i].getBounds())) {
I am getting a InvocationTargetException. Here is the logcat:
01-21 23:10:12.601: W/System.err(13118): java.lang.reflect.InvocationTargetException
01-21 23:10:12.601: W/System.err(13118): at java.lang.reflect.Method.invokeNative(Native Method)
01-21 23:10:12.605: W/System.err(13118): at java.lang.reflect.Method.invoke(Method.java:511)
01-21 23:10:12.605: W/System.err(13118): at org.cocos2d.actions.CCTimer.update(CCTimer.java:82)
01-21 23:10:12.605: W/System.err(13118): at org.cocos2d.actions.CCScheduler.tick(CCScheduler.java:253)
01-21 23:10:12.605: W/System.err(13118): at org.cocos2d.nodes.CCDirector.drawCCScene(CCDirector.java:679)
01-21 23:10:12.605: W/System.err(13118): at org.cocos2d.nodes.CCDirector.onDrawFrame(CCDirector.java:649)
01-21 23:10:12.605: W/System.err(13118): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1462)
01-21 23:10:12.605: W/System.err(13118): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1216)
01-21 23:10:12.605: W/System.err(13118): Caused by: java.lang.NullPointerException
01-21 23:10:12.608: W/System.err(13118): at com.qasim.platformer.GameLayer.canExecuteMovement(GameLayer.java:107)
01-21 23:10:12.608: W/System.err(13118): at com.qasim.platformer.GameLayer.gameLoop(GameLayer.java:86)
01-21 23:10:12.608: W/System.err(13118): ... 8 more
01-21 23:10:12.620: D/dalvikvm(13118): GC_CONCURRENT freed 460K, 6% free 9279K/9863K, paused 2ms+3ms
01-21 23:10:12.624: I/DD(13118): guy:Rect(252, 63 - 300, 111)
What could be the problem? the getBounds() class in guy is this:
public Rect getBounds() {
return new Rect(x, y, x+width, y+height);
}
InvocationTargetException
is just a wrapper for an exception that's thrown within a dynamic invocation. The true problem is the NullPointerException
that it's wrapping:
Caused by: java.lang.NullPointerException
at com.qasim.platformer.GameLayer.canExecuteMovement(GameLayer.java:107)
at com.qasim.platformer.GameLayer.gameLoop(GameLayer.java:86)
As you've pointed out, this is the offending line:
if (Rect.intersects(projectedBounds, platform[i].getBounds())) {
The only place a null pointer could be happening on this line is at platform[i].getBounds()
. Either platform
itself is null
, or the element at platform[i]
is.
来源:https://stackoverflow.com/questions/8958882/why-am-i-getting-an-invocationtargetexception-android-2d-game