Is it possible to get application's context in an Android Library Project?

There is one more way, add application class in your library project:

/**
 * Base class for those who need to maintain global application state.
 */
public class LibApp extends Application {

  /** Instance of the current application. */
  private static LibApp instance;

  /**
   * Constructor.
   */
  public LibApp() {
    instance = this;
  }

  /**
   * Gets the application context.
   * 
   * @return the application context
   */
  public static Context getContext() {
    return instance;
  }

}

Then in your regular project make the real application class extend LibApp:

/**
 * Base class for those who need to maintain global application state.
 */
public class App extends LibApp {

  @Override
  public void onCreate() {
    super.onCreate();
  }

}

Make sure that you have "Name" defined in AndroidManifest:

<application android:name="App" ...>

and that your App class is in the base package.

You can then use LibApp.getContext() your library project to get the application context of the application that is using the library.

This may not be good solution but it works for me. I am sharing it because it might be useful to somebody else.

Is it possible?

Yes.

If yes, how?

Pass it in as a parameter.

I don't want my user to pass context in parameter to my library project because it is possible that my library project will be called through JNI and I have no idea how I can get context in JNI and pass it to Java layer.

Then figure out "how [you] can get context in JNI and pass it to Java layer". I would imagine that you would pass it like any other object. As @Blundell noted, you do not really have any other option.

There's another way to get context in jni, neither passing a parameter nor saving context by yourself, but by using android api. I found that there's a class named:

• android.app.AppGlobals

in the source code. And the static function

• getInitialApplication

  can return an Application object. But it must be called in main thread, and the class is hidden. Anyway you can use it by reflecting in java. And you can just use FindClass() and FindStaticObjectMethod() to find out the method, and use it. Hope that helps.