Blankj/AndroidUtilCode · error · IllegalArgumentException

presenterClass is null!

Error message

presenterClass is null!

What it means

BaseView.getPresenter(Class) throws IllegalArgumentException when the requested presenter class argument is null. It is a contract check: a null class key cannot be looked up in the presenter map, so the call is rejected before any map access.

Source

Thrown at lib/base/src/main/java/com/blankj/base/mvp/BaseView.java:76

    public <T extends Fragment> T getFragment() {
        if (mFragment == null) {
            return null;
        }
        //noinspection unchecked
        return (T) mFragment;
    }

    public V addPresenter(BasePresenter<V> presenter) {
        if (presenter == null) return (V) this;
        mPresenterMap.put(presenter.getClass(), presenter);
        //noinspection unchecked
        presenter.bindView((V) this);
        return (V) this;
    }

    public <P extends BasePresenter<V>> P getPresenter(Class<P> presenterClass) {
        if (presenterClass == null) {
            throw new IllegalArgumentException("presenterClass is null!");
        }
        BasePresenter<V> basePresenter = mPresenterMap.get(presenterClass);
        if (basePresenter == null) {
            throw new IllegalArgumentException("presenter of <" + presenterClass.getSimpleName() + "> is not added!");
        }
        //noinspection unchecked
        return (P) basePresenter;
    }

    @CallSuper
    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    public void onDestroy() {
        Log.i(TAG, "destroy view: " + getClass().getSimpleName());
        removeLifecycle(this);
        for (BasePresenter<V> presenter : mPresenterMap.values()) {
            if (presenter != null) {
                presenter.onDestroy();
            }

View on GitHub (pinned to 7b4caf9e54)

Solutions

1. Pass the concrete presenter class literal, e.g. getPresenter(LoginPresenter.class), never a possibly-null variable.
2. Initialise any Class field you intend to pass before the getPresenter call, or assert it is non-null.
3. If the presenter class is optional, branch on the field being null instead of calling getPresenter(null).

Example fix

// before
Class<? extends BasePresenter<V>> cls = null;
getPresenter(cls); // throws

// after
getPresenter(LoginPresenter.class);

if (presenterClass != null) {
    getPresenter(presenterClass);
}

private static boolean isPresenterClassKnown(Class<?> c) {
    return c != null && BasePresenter.class.isAssignableFrom(c);
}

When it happens

Trigger: Calling getPresenter(null), or getPresenter(someField) where someField is a Class reference that has not been initialised (still null), e.g. a presenter class loaded lazily or conditionally.

Common situations: A field holding the presenter Class is left null due to a missed initialisation; passing a Class obtained from a dynamic lookup that returned null; copy-paste leaving a placeholder null in a getPresenter call.

Related errors

• presenter of <{}> is not added!
• ContentView is null.
• context is not instance of Activity.
• onCreateViewHolder: get holder from view type failed.
• Invalid orientation. It should be either HORIZONTAL or VERTI

AI-assisted analysis of Blankj/AndroidUtilCode@7b4caf9e54 (2026-08-14). Data as JSON: /api/errors/0df09ae2ee6266b5. Report an issue: GitHub.