Fragment_display_message: My first android app error

I am developing a mobile app for the first time

Environment: Eclipse Kepler, Java 1.7 Backend:

I followed these steps:

1) Installed Android SDK and launched Android SDK Manager and installed required files

2) Installed ADT plugin Eclipse ADT: https://dl-ssl.google.com/android/eclipse

At this point in some standard docs, he said that now you have to create an AVD, the AVD icon should appear on my toolbar, but I couldn't find it anywhere.

Now I am trying to develop my first app as shown in this site: http://developer.android.com/training/basics/firstapp/index.html

I am adding my code snippets as shown below:

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
</LinearLayout>

      

        
        
        
      

    

strings.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">My First App</string>
<string name="edit_message">Enter a message</string>
<string name="button_send">Send</string>
<string name="action_settings">Settings</string>
<string name="title_activity_main">MainActivity</string>
<string name="uploading">Uploading…</string>
<string name="hello_world">Hello world!</string>
<string name="title_activity_display_message">DisplayMessageActivity</string>
</resources>

      

        
        
        
      

    

AndroidManifest.xml:

<!--  <?xml version="1.0" encoding="utf-8" standalone="no"?> -->
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.amazon.demo"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
    android:minSdkVersion="16" 
    android:targetSdkVersion ="20" />
<uses-permission android:name="android.permission.INTERNET" />
<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" 
    android:allowBackup="true" >      
    <activity
        android:name=".MainActivity"
        android:label="@string/title_activity_main" >
    </activity>
    <activity
        android:name=".DisplayMessageActivity"
        android:label="@string/title_activity_display_message"
        android:parentActivityName="com.amazon.demo.MainActivity" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.amazon.demo.MainActivity" />
    </activity>        
</application>    
</manifest>

      

        
        
        
      

    

MainActivity.java

public class MainActivity extends ActionBarActivity {   
public final static String EXTRA_MESSAGE = "com.amazon.demo.MESSAGE";
@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 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);
}   
public void sendMessage(View view) {
     Intent intent = new Intent(this, DisplayMessageActivity.class);
        EditText editText = (EditText) findViewById(R.id.edit_message);
        String message = editText.getText().toString();
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
}   
}

      

        
        
        
      

    

activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" 
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.amazon.demo.MainActivity" >
 <EditText android:id="@+id/edit_message"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:hint="@string/edit_message" />
 <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/button_send"
    android:onClick="sendMessage" />
</LinearLayout>

      

        
        
        
      

    

DisplayMessageActivity.java:

public class DisplayMessageActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_display_message);
    // Get the message from the intent
    Intent intent = getIntent();
    String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
    // Create the text view
    TextView textView = new TextView(this);
    textView.setTextSize(40);
    textView.setText(message);
    // Set the text view as the activity layout
    setContentView(textView);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.display_message, 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);
}   
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_display_message,container, false);
          return rootView;
   }
}
}

      

        
        
        
      

    

activity_display_message.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.amazon.demo.DisplayMessageActivity" >
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />
</RelativeLayout>

      

        
        
        
      

    

Now, unlike My First App crashes on button click , I do not have fragment_main.xml and fragment_display_message.xml files anywhere in my project. Are these two files self-generated? Or should we create them separately?

Also have I set all the prerequisites for developing an Android app correctly? I'm not sure.

Also, DisplayMessageActivity.java says: fragment_display_message cannot be resolved or is not a field

Hence, I cannot run the file.

Please, help. and I apologize for the long description.