How to use Toolbar at the bottom of activity.

/res/menu/bottom_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<item
    android:id="@+id/add"
    android:title="Add"
    app:showAsAction="always"
    />
<item
    android:id="@+id/filter"
    android:title="filter"
    app:showAsAction="always"
    />
<item
    android:id="@+id/sort"
    android:title="Sort"
    app:showAsAction="always"
    />
</menu>

Activity Part:

Inflate the menu and Add touch listener on MenuItem

ToolBar bottomToolBar = (Toolbar)findViewById(R.id.bottomToolbar);
    bottomToolBar.inflateMenu(R.menu.bottom_menu);
    bottomToolBar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {

        @Override
        public boolean onMenuItemClick(MenuItem item) {

            if(item.getItemId()==R.id.add)
            {
                Toast.makeText(MainActivity.this, "Add", Toast.LENGTH_SHORT).show();
            }
            else if(item.getItemId()== R.id.filter)
            {
                Toast.makeText(MainActivity.this, "Filter", Toast.LENGTH_SHORT).show();
            }
            else if(item.getItemId() == R.id.sort)
            {
                Toast.makeText(MainActivity.this, "Sort", Toast.LENGTH_SHORT).show();
            }

            return false;
        }
    });