android-navigation-jetpack

name	android-navigation-jetpack
description	Expert guidance on using the Jetpack Navigation Component from Java with an XML nav graph, Safe Args, and deep links. Use this when adding screens, passing arguments, or wiring a bottom nav/drawer in a Java project.

Jetpack Navigation Component (Java)

Instructions

Use the Navigation Component as the single navigation engine. One activity hosts a NavHostFragment containing a nav graph; Fragments are destinations.

1. Gradle

plugins {
    id 'com.android.application'
    id 'androidx.navigation.safeargs'   // Java variant generates *Directions / *Args classes
}

dependencies {
    def nav = "2.8.0"
    implementation "androidx.navigation:navigation-fragment:$nav"
    implementation "androidx.navigation:navigation-ui:$nav"
}

The Java Safe Args plugin is androidx.navigation.safeargs, not ...safeargs.kotlin.

2. Nav Graph

<!-- res/navigation/main_graph.xml -->
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_graph"
    app:startDestination="@id/articleListFragment">

    <fragment
        android:id="@+id/articleListFragment"
        android:name="com.example.app.articles.ArticleListFragment"
        android:label="@string/articles">
        <action
            android:id="@+id/action_list_to_detail"
            app:destination="@id/articleDetailFragment" />
    </fragment>

    <fragment
        android:id="@+id/articleDetailFragment"
        android:name="com.example.app.articles.ArticleDetailFragment"
        android:label="@string/article_detail">
        <argument
            android:name="articleId"
            app:argType="long" />
        <deepLink app:uri="https://example.com/articles/{articleId}" />
    </fragment>
</navigation>

3. Host in Activity

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/navHost"
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:defaultNavHost="true"
    app:navGraph="@navigation/main_graph" />

Wire the toolbar:

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle s) {
        super.onCreate(s);
        setContentView(R.layout.activity_main);

        NavHostFragment host = (NavHostFragment)
                getSupportFragmentManager().findFragmentById(R.id.navHost);
        NavController nav = Objects.requireNonNull(host).getNavController();

        setSupportActionBar(findViewById(R.id.toolbar));
        NavigationUI.setupActionBarWithNavController(this, nav);
    }

    @Override
    public boolean onSupportNavigateUp() {
        return Navigation.findNavController(this, R.id.navHost).navigateUp()
                || super.onSupportNavigateUp();
    }
}

4. Safe Args (Java)

Safe Args generates ArticleListFragmentDirections and ArticleDetailFragmentArgs.

Navigate:

NavDirections direction =
        ArticleListFragmentDirections.actionListToDetail().setArticleId(article.id());
Navigation.findNavController(view).navigate(direction);

Read arguments:

public class ArticleDetailFragment extends Fragment {
    private long articleId;

    @Override
    public void onCreate(Bundle s) {
        super.onCreate(s);
        articleId = ArticleDetailFragmentArgs.fromBundle(requireArguments()).getArticleId();
    }
}

If an action has no args, use the generated no-arg factory method directly. Never hand-craft Bundle keys.

5. Deep Links

Add <intent-filter> to the host Activity:

<intent-filter android:autoVerify="true">
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="https" android:host="example.com" android:pathPrefix="/articles" />
</intent-filter>

The nav graph's <deepLink> entries match incoming URIs automatically.

6. Bottom Nav / Drawer

BottomNavigationView nav = binding.bottomNav;
NavigationUI.setupWithNavController(nav, navController);

Use multiple nav graphs, one per tab, when the tabs have independent back stacks (NavigationUI.setupWithNavController supports this for bottom nav).

Checklist

• Exactly one NavHostFragment per Activity.
• All destinations are declared in XML; no programmatic FragmentTransaction.replace for navigation.
• Arguments are passed via Safe Args, never via manual Bundle.putX.
• Deep links are declared in the nav graph and tested with adb shell am start.
• popUpTo / popUpToInclusive are used to clear stacks on logout / finishing flows.
• Back navigation is handled by onSupportNavigateUp() delegating to NavController.