CODEWITHSUNDEEP
androiddependency-injectionroboguice
Dmitriy Tarasov
Dmitriy Tarasov

Reputation: 1969

Roboguice 2.0 injecting application into POJO

I'm newbe in Roboguice, please help. I have an application calss MyApplication in which in onCreate method i initialize some data. Also i have a POJO with buisiness logic which i want to use in my MainActivity (See code snippets below). I need to inject MyApplication into POJO to get access to data which i initialize in application's onCreate, but this code called before onCreate and i've got a NullPointerException.

public class MyApplication extends Application {

    private Properties applicationProperties;

    @Override
    public void onCreate() {
        super.onCreate();
        applicationProperties = loadApplicationProperties(APPLICATION_PROPERTIES_ASSET);
    }

    @SuppressWarnings("unchecked")
    public String getProperty(String key) {
        return applicationProperties.getProperty(key);
    }

}

@Singleton
public class POJO {

    @Inject
    private MyApplication application;

    @Inject
    public void init() {
        // NPE here, because application onCreate not called at this moment
        serverURL = application.getProperty(Constants.SERVER_URL);
    }
}

public class MainActivity extends RoboActivity {

    @Inject
    private POJO myPOJO;

}

Upvotes: 4

Views: 2055

Answers (2)

Charles Munger
Charles Munger

Reputation: 1407

If the data you need doesn't require a context, just access to XML resources or res/raw, you can inject that from anywhere.

Just use Roboguice.getInjector() to obtain a copy of the Resources object.

Upvotes: 1

Jon Adams
Jon Adams

Reputation: 25137

EDIT: Found a way to do this in RoboGuice 2.0 based on the answer in RoboGuice custom module application context.

Inject the application context in AbstractModule constructor, then bind it in configure() for later injection:

public final class MyModule extends AbstractModule
{
    private final MyApplication context;

    @Inject
    public MyModule(final Context context)
    {
        super();
        this.context = (MyApplication)context;
    }

    @Override
    protected void configure() {
        bind(MyApplication.class).toInstance(context);
    }

}

Upvotes: 3

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