Chapter 9 Earthquake 1

juniper · August 18th, 2010, 01:34 PM

Hi,
I started seeing the same exception, java.lang.ClassCastException: java.lang.String.

By creating a new project, mellowfellow, you cleared out the existing preferences data. The preference data is stored as strings, but if you look at the onStartCommand in EarthquakeService, it's attempting to read an int.

Run Reto's sample code, Chapter 10 Earthquake 3, and change the preferences using the preferences menu. Restart the app and you will see the ClassCastException again.

To fix the code replace this:

Code:

    int minMagIndex = prefs.getInt(Preferences.PREF_MIN_MAG, 0);
    if (minMagIndex < 0)
      minMagIndex = 0;

    int freqIndex = prefs.getInt(Preferences.PREF_UPDATE_FREQ, 0);
    if (freqIndex < 0)
      freqIndex = 0;

    boolean autoUpdate = 
      prefs.getBoolean(Preferences.PREF_AUTO_UPDATE, false);

    Resources r = getResources();
    int[] freqValues = r.getIntArray(R.array.update_freq_values);

    int updateFreq = freqValues[freqIndex];

with this:

Code:

    int updateFreq = Integer.parseInt(prefs.getString(Preferences.PREF_UPDATE_FREQ, "60"));

    boolean autoUpdate = 
      prefs.getBoolean(Preferences.PREF_AUTO_UPDATE, false);

MellowFellow · August 18th, 2010, 02:27 PM

Yes I started getting that Exception again.

I tried the fix you gave, but now I'm getting a different error:

08-18 13:49:18.660: WARN/dalvikvm(714): Exception Ljava/lang/RuntimeException; thrown during Landroid/os/AsyncTask;.<clinit>
08-18 13:49:18.660: WARN/dalvikvm(714): threadid=7: thread exiting with uncaught exception (group=0x4001d800)
08-18 13:49:18.710: ERROR/AndroidRuntime(714): FATAL EXCEPTION: earthquakeUpdates
08-18 13:49:18.710: ERROR/AndroidRuntime(714): java.lang.ExceptionInInitializerError
08-18 13:49:18.710: ERROR/AndroidRuntime(714): at com.paad.earthquake1.EarthquakeService.refreshEart hquakes(EarthquakeService.java:250)
08-18 13:49:18.710: ERROR/AndroidRuntime(714): at com.paad.earthquake1.EarthquakeService.access$0(Ea rthquakeService.java:247)
08-18 13:49:18.710: ERROR/AndroidRuntime(714): at com.paad.earthquake1.EarthquakeService$1.run(Earth quakeService.java:191)
08-18 13:49:18.710: ERROR/AndroidRuntime(714): at java.util.Timer$TimerImpl.run(Timer.java:289)
08-18 13:49:18.710: ERROR/AndroidRuntime(714): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
08-18 13:49:18.710: ERROR/AndroidRuntime(714): at android.os.Handler.<init>(Handler.java:121)

juniper · August 18th, 2010, 07:53 PM

Hi MellowFellow,
I'd think you'd get better results running "Chapter 9 Earthquake 4" which uses an alarm instead of timer.

I had a lot of force closes while running Chapter 9 Earthquake 1-3. Reto mentions:

Quote:

At this stage the earthquake processing is done in a Service, but itâs still being executed on the main GUI
thread. Later in this chapter youâll learn how to move time-consuming operations onto background
threads to improve performance and avoid ââForce Closeââ messages.
Similarly, the Service is constantly running, taking up valuable resources. Later sections will explain
how to replace the Timer with Alarms.

MellowFellow · August 19th, 2010, 05:18 PM

I got Earthquake 4 running now after including the last fix you gave me, thanks. But I'm still seeing a non-fatal cursor error popping up whenever a new earthquake is detected (the same cursor not closed error we had before). The preferences screens also do not work anymore, they cause a force closure when selected.

juniper · August 23rd, 2010, 04:40 PM

Hi MellowFellow,
You have to apply the same two fixes from Chapter 7 (addNewQuake and loadQuakesFromProvider) described here:
Fix: Chapter 7 - Earthquake IllegalStateException Finalizing cursor

addNewQuake is now in EarthquakeService.