How to Create an Activity using Fragment in Android?

 
package com.example.create_fragment;
 
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
//creating two fragments in an activity to show the current time in milli secs. 
@SuppressLint("NewApi")
public class MainActivity extends Activity implements fragment2.Listener {
 
    @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.main, menu);
        return true;
    }
 
    @Override
    public void onItemSelected(String str) {
        // TODO Auto-generated method stub
        fragment1 fragment = (fragment1) getFragmentManager().findFragmentById(
                R.id.Fragment1);
        if (fragment != null && fragment.isInLayout()) {
            fragment.setText(str);
        }
    }
 
}

 
package com.example.create_fragment;
 
import android.annotation.SuppressLint;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
 
@SuppressLint("NewApi")
public class fragment1 extends Fragment {
 
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment1, container, false);
        return view;
    }
 
    public void setText(String item) {
        TextView view = (TextView) getView().findViewById(R.id.textView1);
        view.setText(item);
    }
}

 
package com.example.create_fragment;
 
 
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.os.SystemClock;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
 
@SuppressLint("NewApi")
public class fragment2 extends Fragment {
    private Listener listener;
 
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment2, container, false);
        Button button = (Button) view.findViewById(R.id.button1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                updateDetail();
            }
        });
        return view;
    }
 
    public interface Listener {
        public void onItemSelected(String link);
    }
 
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        if (activity instanceof Listener) {
            listener = (Listener) activity;
        } else {
            throw new ClassCastException(activity.toString()
                    + " must implemenet fragement2.listener");
        }
    }
 
    public void updateDetail() {
        String newTime = String.valueOf(System.currentTimeMillis());
        listener.onItemSelected(newTime);
    }
 
    @Override
    public void onDetach() {
        // TODO Auto-generated method stub
        super.onDetach();
        listener = null;
    }
}