CODEWITHSUNDEEP
javaandroidgoogle-app-enginedatanucleus
user198923
user198923

Reputation: 489

The PersistenceManagerFactory class must define a static method?

I am attempting to connect my android app to my backend endpoints (in Google's App Engine) so that I can store my java objects in Google's datastore. However when I try to initialize the PersistenceManagerFactory object, I get the error seen at the end of this post - The PersistenceManagerFactory class must define a static method.

I am trying to initialize the object using the following code, and note: I do have the library in the classpath.

public static PersistenceManagerFactory InitializePersistanceManagerClass(){
        Properties properties = new Properties();
        properties.setProperty("javax.jdo.PersistenceManagerFactoryClass", "org.datanucleus.api.jdo.JDOPersistenceManagerFactory");
        properties.setProperty("javax.jdo.option.ConnectionURL", "appengine");
        properties.setProperty("javax.jdo.option.NontransactionalRead", "true");
        properties.setProperty("javax.jdo.option.NontransactionalWrite", "true");
        properties.setProperty("javax.jdo.option.RetainValues", "true");
        properties.setProperty("datanucleus.appengine.autoCreateDatastoreTxns", "true");
        properties.setProperty("datanucleus.appengine.singletonPMFForName", "true");
        PersistenceManagerFactory pmf = JDOHelper.getPersistenceManagerFactory(properties);
        return pmf;
    }

There is no line number listed in the error, however I am 90% sure the problem lies in the code above, or the class that I am using for the persistenceManagerFactory. The error when this code runs appears below. Any ideas? I really don't understand what the problem is....

   08-23 09:10:31.826    7932-7932/com.myApp.myModule E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.myApp.myModule, PID: 7932
    javax.jdo.JDOFatalInternalException: The PersistenceManagerFactory class must define a static method
    PersistenceManagerFactory getPersistenceManagerFactory(Map props).
    The class "org.datanucleus.jdo.JDOPersistenceManagerFactory"
    defines a non-static getPersistenceManagerFactory(Map props) method.
            at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(Unknown Source)
            at javax.jdo.JDOHelper.getPersistenceManagerFactory(Unknown Source)
            at javax.jdo.JDOHelper.getPersistenceManagerFactory(Unknown Source)
            at com.myApp.myModule.forStorage.PMF.<init>(Unknown Source)
            at com.myApp.myModule.Login.onConnected(Unknown Source)
            at wz.a(Unknown Source)
            at rb.e(Unknown Source)
            at rb.d(Unknown Source)
            at rd.onConnected(Unknown Source)
            at wz.a(Unknown Source)
            at wz.a(Unknown Source)
            at wy.a(Unknown Source)
            at wy.a(Unknown Source)
            at wv.b(Unknown Source)
            at wu.handleMessage(Unknown Source)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:852)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:668)
            at dalvik.system.NativeStart.main(Native Method)
    NestedThrowablesStackTrace:
    java.lang.NullPointerException
            at javax.jdo.JDOHelper.forName(Unknown Source)
            at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(Unknown Source)
            at javax.jdo.JDOHelper.getPersistenceManagerFactory(Unknown Source)
            at javax.jdo.JDOHelper.getPersistenceManagerFactory(Unknown Source)
            at com.myApp.myModule.forStorage.PMF.<init>(Unknown Source)
            at com.myApp.myModule.Login.onConnected(Unknown Source)
            at wz.a(Unknown Source)
            at rb.e(Unknown Source)
            at rb.d(Unknown Source)
            at rd.onConnected(Unknown Source)
            at wz.a(Unknown Source)
            at wz.a(Unknown Source)
            at wy.a(Unknown Source)
            at wy.a(Unknown Source)
            at wv.b(Unknown Source)
            at wu.handleMessage(Unknown Source)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:852)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:668)
            at dalvik.system.NativeStart.main(Native Method)

Upvotes: 1

Views: 483

Answers (1)

jawee
jawee

Reputation: 271

From the javax/jdo/Bundle.properties, we can see the below definition.
EXC_GetPMFNullPointerException = The PersistenceManagerFactory class must define a static methodPersistenceManagerFactory getPersistenceManagerFactory(Map props). The class "{0}" defines a non-static getPersistenceManagerFactory(Map props) method.

From the javax.jdo.JDOHelper source code, we can deduce that the below error message "The PersistenceManagerFactory class must define a static method PersistenceManagerFactory getPersistenceManagerFactory(Map props). The class org.datanucleus.jdo.JDOPersistenceManagerFactory defines a non-static getPersistenceManagerFactory(Map props) method." is coming from the below code in invokeGetPersistenceManagerFactoryOnImplementation method.

    catch (NullPointerException e) {
throw new JDOFatalInternalException (msg.msg("EXC_GetPMFNullPointerException", pmfClassName), e);}

This is caused by java.lang.NullPointerException at javax.jdo.JDOHelper.forName(Unknown Source), which is mostly probably coming form Class.forName(name, init, loader);
Anyway, you could modify the javax.jdo.JDOHelper.forName method to add some more traces & print more exception info in it. It's not difficult.
If requried, you tell me the version for "jdo-api", then, I could provide one for you.

Upvotes: 1

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