```
public class ToolBarNavigation extends AppCompatActivity {

  public void exe (int address){

    RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
        RelativeLayout.LayoutParams.MATCH_PARENT,
        RelativeLayout.LayoutParams.WRAP_CONTENT);

    RelativeLayout relativeLayout = (RelativeLayout) findViewById(address);

    LayoutInflater layoutInflater = (LayoutInflater) getBaseContext().getSystemService(getBaseContext().LAYOUT_INFLATER_SERVICE);

    View view = layoutInflater.inflate(R.layout.toolbar_navigation, null);

    lp.addRule(RelativeLayout.ALIGN_PARENT_TOP);

    view.setLayoutParams(lp);

    relativeLayout.addView(view);
  }
}

public class MainActivity extends AppCompatActivity {

  ToolBarNavigation t1 = new ToolBarNavigation();

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    t1.exe(R.id.relativeLayout1);
  }
}

```

Error:

```
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.m01nyabesh.yabesh/com.m01nyabesh.yabesh.MainActivity}: java.lang.NullPointerException
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
   at android.app.ActivityThread.access$600(ActivityThread.java:141)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
   at android.os.Handler.dispatchMessage(Handler.java:99)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:5103)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:525)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
   at android.app.Activity.findViewById(Activity.java:1853)
   at com.m01nyabesh.yabesh.ToolBarNavigation.exe(ToolBarNavigation.java:16)
   at com.m01nyabesh.yabesh.MainActivity.onCreate(MainActivity.java:24)
   at android.app.Activity.performCreate(Activity.java:5133)
   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
   at android.app.ActivityThread.access$600(ActivityThread.java:141) 
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
   at android.os.Handler.dispatchMessage(Handler.java:99) 
   at android.os.Looper.loop(Looper.java:137) 
   at android.app.ActivityThread.main(ActivityThread.java:5103) 
   at java.lang.reflect.Method.invokeNative(Native Method) 
   at java.lang.reflect.Method.invoke

```