我在StackOverflow中看到了很多FATAL EXCEPTION问题。但是不同的人有不同的问题。所以我想讨论我的问题是否可以有线索。
我有AcceInterface Class和RawData Class。 AcceInterface Class读取加速度计数据并放入三个队列（queuex，queuey，queuez）。然后RawData Class在Runnable THread中读取这些队列并使用AChartEngine显示。
这是AcceInterface Class。
public class AcceInterface implements SensorEventListener {
private SensorManager sensorManager;
private Sensor accelerometer;
public Queue<Float> queuex;
public Queue<Float> queuey;
public Queue<Float> queuez;
//Filter
IIRDirectForm2Transposed filt = new IIRDirectForm2Transposed();
public void createSensorContext(Context context){
sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
if (sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null) {
// success! we have an accelerometer
accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_GAME);
// vibrateThreshold = accelerometer.getMaximumRange() / 2;
} else {
// fai! we dont have an accelerometer!
}
queuex = new ConcurrentLinkedQueue<Float>();
queuey = new ConcurrentLinkedQueue<Float>();
queuez = new ConcurrentLinkedQueue<Float>();
//Initialize filter
filt.initialization();
}
public void deleteSensor(){
sensorManager.unregisterListener(this);
queuex.clear();
queuey.clear();
queuez.clear();
}
@Override
public void onSensorChanged(SensorEvent event) {
//Filter before put into queues
filt.IIRDirectForm2TransposedFilteration(event.values[0], event.values[1],event.values[2]);
queuex.add(Float.valueOf(filt.out[0]));
queuey.add(Float.valueOf(filt.out[1]));
queuez.add(Float.valueOf(filt.out[2]));
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
}
然后Runnable类如下。
acce = new AcceInterface();
class Plot implements Runnable
{
Thread mythread ;
Plot()
{
mythread = new Thread(this, "my runnable thread");
System.out.println("my thread created" + mythread);
mythread.start();
}
public void run()
{
while (systemON) {
if (!acce.queuex.isEmpty()) {
mSeriesX.add(xx_axis++, acce.queuex.poll().floatValue());
if (xx_axis % 50 == 0) {
mChartView_x.repaint();
}
if (xx_axis % 3000 == 0) {
mRenderer_x.setXAxisMin(xx_axis);
mRenderer_x.setXAxisMax(xx_axis + 3000);
}
//if (mChartView_x != null) {
//}
}
if (!acce.queuey.isEmpty()) {
mSeriesY.add(xy_axis++, acce.queuey.poll().floatValue());
if (xy_axis % 50 == 0) {
mChartView_y.repaint();
}
if (xy_axis % 3000 == 0) {
mRenderer_y.setXAxisMin(xy_axis);
mRenderer_y.setXAxisMax(xy_axis + 3000);
}
// if (mChartView_y != null) {
//}
}
if (!acce.queuez.isEmpty()) {
mSeriesZ.add(xz_axis++, acce.queuez.poll().floatValue());
if (xz_axis % 50 == 0) {
mChartView_z.repaint();
}
if (xz_axis % 3000 == 0) {
mRenderer_z.setXAxisMin(xz_axis);
mRenderer_z.setXAxisMax(xz_axis + 3000);
}
// if (mChartView_y != null) {
//}
}
}
}
}
我的问题是程序偶尔崩溃，无法找到原因。 logcat如下。
E/AndroidRuntime: FATAL EXCEPTION: main
java.util.ConcurrentModificationException
at java.util.TreeMap$MapIterator.stepForward(TreeMap.java:883)
at java.util.TreeMap$BoundedMap$BoundedIterator.stepForward(TreeMap.java:1485)
at java.util.TreeMap$BoundedMap$BoundedEntrySet$1.next(TreeMap.java:1513)
at java.util.TreeMap$BoundedMap$BoundedEntrySet$1.next(TreeMap.java:1511)
at org.achartengine.chart.XYChart.draw(XYChart.java:250)
at org.achartengine.GraphicalView.onDraw(GraphicalView.java:166)
at android.view.View.draw(View.java:13767)
at android.view.View.getDisplayList(View.java:12718)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3201)
at android.view.View.getDisplayList(View.java:12654)
at android.view.View.getDisplayList(View.java:12762)
at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:1144)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2301)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2173)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1981)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1131)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4611)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
at android.view.Choreographer.doCallbacks(Choreographer.java:555)
at android.view.Choreographer.doFrame(Choreographer.java:525)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4898)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
at dalvik.system.NativeStart.main(Native Method)