MainActivity.java

package xyz.app.sharetest;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.support.v7.widget.ShareActionProvider;

public class MainActivity extends AppCompatActivity {

    private ShareActionProvider mShareActionProvider;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate menu resource file.
        getMenuInflater().inflate(R.menu.menu_main, menu);

        // Locate MenuItem with ShareActionProvider
        MenuItem item = menu.findItem(R.id.action_share);

        // Fetch and store ShareActionProvider
        mShareActionProvider = (ShareActionProvider) MenuItemCompat.getActionProvider(item);
        setShareIntent(getShareIntent());

        // Return true to display menu
        return true;
    }

    private Intent getShareIntent() {
        Intent shareIntent = new Intent(Intent.ACTION_SEND);
        shareIntent.setType("text/plain");
        shareIntent.putExtra(Intent.EXTRA_SUBJECT, "subject");
        shareIntent.putExtra(Intent.EXTRA_TEXT, "text");

        return shareIntent;
    }

    // Call to update the share intent
    private void setShareIntent(Intent shareIntent) {
        if (mShareActionProvider != null) {
            mShareActionProvider.setShareIntent(shareIntent);
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        Integer id = item.getItemId();
        Log.d("MainActivity", "id = " + id);
        Log.d("MainActivity", "shareid = " + R.id.action_share);
        Log.d("MainActivity", "Why won't this happen?");

        if (id.equals(R.id.action_share)) {
            Log.d("MainActivity", "Why won't this happen? 2");
        }

        return super.onOptionsItemSelected(item);
    }
}