Android swipe view - error

I am trying to implement a swipe view without tabs, but the app crashes.

Here is the code:

MainActivity.java

package com.application;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

public class MainActivity extends FragmentActivity 
{
    private ViewPager viewPager;
    private PagerAdapter pagerAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        pagerAdapter = new PagerAdapter(getSupportFragmentManager());
        viewPager = (ViewPager)findViewById(R.id.view_pager);

        viewPager.setAdapter(pagerAdapter);
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://ift.tt/nIICcg"
    xmlns:tools="http://ift.tt/LrGmb4"
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

PagerAdapter.java

package com.application;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

public class PagerAdapter extends FragmentPagerAdapter 
{
    public PagerAdapter(FragmentManager fragmentManager)
    {
        super(fragmentManager);
    }

    @Override
    public Fragment getItem(int arg0) {

        switch(arg0)
        {
            case 0:
                return new AndroidFragment();
            case 1:
                return new IosFragment();
            case 2:
                return new WindowsFragment();
        }

        return null;
    }

    @Override
    public int getCount() {
        return 3;
    }

}

AndroidFragment.java

package com.application;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class AndroidFragment extends Fragment 
{
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        View view = inflater.inflate(R.layout.fragment_android, container);

        ((TextView)view.findViewById(R.id.text_view)).setText("Android");

        return view;
    }
}

fragment_android.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_gravity="center" >

    <TextView android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="50sp" />

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://ift.tt/nIICcg"
    package="com.application"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="7"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

IosFragment and WindowsFragment are just like AndroidFragment.

And it gives me the error:

Choreographer.doCallbacks(int, long) line: 558  
Choreographer.doFrame(long, int) line: 525  
Choreographer$FrameDisplayEventReceiver.run() line: 711 
Handler.handleCallback(Message) line: 615   
Choreographer$FrameHandler(Handler).dispatchMessage(Message) line: 92   
Looper.loop() line: 137 
ActivityThread.main(String[]) line: 4921    
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
Method.invoke(Object, Object...) line: 511  
ZygoteInit$MethodAndArgsCaller.run() line: 1038 
ZygoteInit.main(String[]) line: 805 
NativeStart.main(String[]) line: not available [native method]