Android - codigo MainActivity

package com.example.proyecto004;

import android.support.v7.app.ActionBarActivity;

import android.support.v7.app.ActionBar;

import android.support.v4.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.os.Build;

public class MainActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {

            getSupportFragmentManager().beginTransaction()

                    .add(R.id.container, new PlaceholderFragment())

                    .commit();

        }

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    /**

     * A placeholder fragment containing a simple view.

     */

    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {

        }

        @Override

        public View onCreateView(LayoutInflater inflater, ViewGroup container,

                Bundle savedInstanceState) {

            View rootView = inflater.inflate(R.layout.fragment_main, container, false);

            return rootView;

        }

    }

}

y no se genera el codigo standrard el cual tengo que copiarlo de alguna pagina de internet el cual es este :

package com.javaya.proyecto002;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

public class MainActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.activity_main, menu);

        return true;

    }

}