title: must implement OnFragmentInteractionListener error in Android Studio
body: <p>I want to make an app with both bottom navigation and tab in a single activity. But when I am trying to put the tab inside the navigation fragment one exception comes.
  <a href="https://i.stack.imgur.com/8culq.png" rel="nofollow noreferrer">I want to design like this with two toolbars one is bottom navigation and other is tab</a></p>
  
  <p>Please help</p>
  
  <p><strong>LauncherActivity.java</strong></p>
  
  <pre><code>package com.cornicore.dream11statistics;
  
  import android.app.Fragment;
  import android.support.annotation.NonNull;
  import android.support.design.widget.BottomNavigationView;
  import android.support.v4.widget.DrawerLayout;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.MenuItem;
  import android.view.View;
  import android.webkit.WebChromeClient;
  import android.webkit.WebView;
  import android.widget.FrameLayout;
  import android.widget.ProgressBar;
  
  public class LauncherActivity extends AppCompatActivity {
  
  
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_launcher);
  
  
  // Bottom Navigation Start
  
          BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation);
          bottomNav.setOnNavigationItemSelectedListener(navListner);
  
          getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,new HomeFragment()).commit();
  
  // Bottom Navigation
  
      }
  
  
  // Bottom Navigation Start
      private BottomNavigationView.OnNavigationItemSelectedListener navListner = new BottomNavigationView.OnNavigationItemSelectedListener() {
                  @Override
                  public boolean onNavigationItemSelected(@NonNull MenuItem item) {
  
                      android.support.v4.app.Fragment selectedFragment = null;
                      switch(item.getItemId()){
                          case R.id.nav_home:
                              selectedFragment = new HomeFragment();
                              break;
  
                          case R.id.nav_pointtable:
                              selectedFragment = new PointTableFragment();
                              break;
  
                          case R.id.nav_share:
                              selectedFragment = new ShareFragment();
                              break;
                      }
  
  
                      getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,selectedFragment).commit();
                      return true;
                  }
              };
  
  // Bottom Navigation Start
  
  
  
  }
  </code></pre>
  
  <p><strong>HomeFragment.java</strong></p>
  
  <pre><code>    package com.cornicore.dream11statistics;
  
  import android.net.Uri;
  import android.os.Bundle;
  import android.support.annotation.Nullable;
  import android.support.design.widget.TabLayout;
  import android.support.v4.app.Fragment;
  import android.support.v4.app.FragmentManager;
  import android.support.v4.view.ViewPager;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.webkit.WebChromeClient;
  import android.webkit.WebView;
  import android.webkit.WebViewClient;
  import android.widget.ProgressBar;
  
  public class HomeFragment extends Fragment implements Tab1.OnNavFragmentInteractionListener,Tab2.OnNavFragmentInteractionListener,Tab3.OnNavFragmentInteractionListener {
  
  
  
      @Nullable
      @Override
      public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
  
          View v = inflater.inflate(R.layout.fragment_home,container,false);
  
          TabLayout tabLayout = v.findViewById(R.id.tablayout);
          tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
          tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
          tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
          tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
  
  
          final ViewPager viewPager = v.findViewById(R.id.pager);
          final android.support.v4.view.PagerAdapter adapter = new PagerAdapter(getActivity().getSupportFragmentManager(),tabLayout.getTabCount());
          viewPager.setAdapter(adapter);
          viewPager.setOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
  
          tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
              @Override
              public void onTabSelected(TabLayout.Tab tab) {
                  viewPager.setCurrentItem(tab.getPosition());
              }
  
              @Override
              public void onTabUnselected(TabLayout.Tab tab) {
  
              }
  
              @Override
              public void onTabReselected(TabLayout.Tab tab) {
  
              }
          });
  
  
  
          return v;
      }
  
      public void onNavFragmentInteraction(Uri uri) {
  
      }
  
  
  }
  </code></pre>
  
  <p><strong>Tab1.java</strong></p>
  
  <pre><code>package com.cornicore.dream11statistics;
  
  import android.content.Context;
  import android.net.Uri;
  import android.os.Bundle;
  import android.support.v4.app.Fragment;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.webkit.WebChromeClient;
  import android.webkit.WebView;
  import android.webkit.WebViewClient;
  import android.widget.ProgressBar;
  
  
  /**
   * A simple {@link Fragment} subclass.
   * Activities that contain this fragment must implement the
   * {@link Tab1.OnFragmentInteractionListener} interface
   * to handle interaction events.
   * Use the {@link Tab1#newInstance} factory method to
   * create an instance of this fragment.
   */
  public class Tab1 extends Fragment {
  
      ProgressBar progressBar;
      WebView webView;
  
      // TODO: Rename parameter arguments, choose names that match
      // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
      private static final String ARG_PARAM1 = "param1";
      private static final String ARG_PARAM2 = "param2";
  
      // TODO: Rename and change types of parameters
      private String mParam1;
      private String mParam2;
  
      private OnFragmentInteractionListener mListener;
  
      public Tab1() {
          // Required empty public constructor
      }
  
      /**
       * Use this factory method to create a new instance of
       * this fragment using the provided parameters.
       *
       * @param param1 Parameter 1.
       * @param param2 Parameter 2.
       * @return A new instance of fragment Tab1.
       */
      // TODO: Rename and change types and number of parameters
      public static Tab1 newInstance(String param1, String param2) {
          Tab1 fragment = new Tab1();
          Bundle args = new Bundle();
          args.putString(ARG_PARAM1, param1);
          args.putString(ARG_PARAM2, param2);
          fragment.setArguments(args);
          return fragment;
      }
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          if (getArguments() != null) {
              mParam1 = getArguments().getString(ARG_PARAM1);
              mParam2 = getArguments().getString(ARG_PARAM2);
          }
  
  
  
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
          // Inflate the layout for this fragment
          return inflater.inflate(R.layout.fragment_tab1, container, false);
      }
  
      // TODO: Rename method, update argument and hook method into UI event
      public void onButtonPressed(Uri uri) {
          if (mListener != null) {
              mListener.OnNavFragmentInteractionListener(uri);
          }
      }
  
      @Override
      public void onAttach(Context context) {
          super.onAttach(context);
          if (context instanceof OnFragmentInteractionListener) {
              mListener = (OnFragmentInteractionListener) context;
          } else {
              throw new RuntimeException(context.toString() + " must implement OnFragmentInteractionListener");
          }
      }
  
      @Override
      public void onDetach() {
          super.onDetach();
          mListener = null;
      }
  
  
      public interface OnFragmentInteractionListener {
           void OnNavFragmentInteractionListener(Uri uri);
  
      }
  
      public interface OnNavFragmentInteractionListener {
      }
  
  
      /**
       * This interface must be implemented by activities that contain this
       * fragment to allow an interaction in this fragment to be communicated
       * to the activity and potentially other fragments contained in that
       * activity.
       * &lt;p&gt;
       * See the Android Training lesson &lt;a href=
       * "http://developer.android.com/training/basics/fragments/communicating.html"
       * &gt;Communicating with Other Fragments&lt;/a&gt; for more information.
       */
  
  
  
  }
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>05-15 11:12:18.862 4926-4926/com.cornicore.dream11statistics E/AndroidRuntime: FATAL EXCEPTION: main
      Process: com.cornicore.dream11statistics, PID: 4926
      java.lang.RuntimeException: com.cornicore.dream11statistics.LauncherActivity@c71a909 must implement OnFragmentInteractionListener
          at com.cornicore.dream11statistics.Tab1.onAttach(Tab1.java:93)
          at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1363)
          at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1109)
          at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:996)
          at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:99)
          at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2364)
          at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
          at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2199)
          at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:651)
          at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:167)
          at android.support.v4.view.ViewPager.populate(ViewPager.java:1236)
          at android.support.v4.view.ViewPager.populate(ViewPager.java:1084)
          at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1614)
          at android.view.View.measure(View.java:18827)
          at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
          at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
          at android.view.View.measure(View.java:18827)
          at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:716)
          at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:462)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
          at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
          at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
          at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
          at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
          at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5952)
          at android.widget.FrameLayout.onMeasure(FrameLayout.java:194)
          at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2645)
          at android.view.View.measure(View.java:18827)
          at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2136)
          at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1248)
          at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1484)
          at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1139)
          at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6064)
          at android.view.Choreographer$CallbackRecord.run(Choreographer.java:860)
          at android.view.Choreographer.doCallbacks(Choreographer.java:672)
          at android.view.Choreographer.doFrame(Choreographer.java:608)
          at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:846)
          at android.os.Handler.handleCallback(Handler.java:742)
  </code></pre>
  
  <hr>
  
  <p><strong>Viewpager</strong></p>
  
  <pre><code>final ViewPager viewPager = v.findViewById(R.id.pager);
          final android.support.v4.view.PagerAdapter adapter = new PagerAdapter(getActivity().getSupportFragmentManager(),tabLayout.getTabCount());
          viewPager.setAdapter(adapter);
          viewPager.setOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
  
          tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
              @Override
              public void onTabSelected(TabLayout.Tab tab) {
                  viewPager.setCurrentItem(tab.getPosition());
              }
  
              @Override
              public void onTabUnselected(TabLayout.Tab tab) {
  
              }
  
              @Override
              public void onTabReselected(TabLayout.Tab tab) {
  
              }
          });
  </code></pre>