cordova2.2对于CordovaWebView的配置

Java文件配置：官方说明不够清晰

package org.apache.cordova.example;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import org.apache.cordova.*;
import org.apache.cordova.api.CordovaInterface;
import org.apache.cordova.api.CordovaPlugin;

public class cordovaExample extends Activity implements CordovaInterface{  
    
    CordovaWebView cordovaWebView;  
      
    private final ExecutorService threadPool =Executors.newCachedThreadPool();  
      
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
          
        setContentView(R.layout.main);  
          
        cordovaWebView=(CordovaWebView) findViewById(R.id.tutoriaView);  
          
        cordovaWebView.loadUrl("file:///android_asset/www/index.html");  
    }  
  
    @Override  
    public void cancelLoadUrl() {  
          
    }  
  
    @Override  
    public Activity getActivity() {  
        return this;  
    }  
  
    @Override  
    public Context getContext() {  
        return this.getContext();  
    }  
  
    @Override  
    public ExecutorService getThreadPool() {  
        return threadPool;  
    }  
  
    @Override  
    public Object onMessage(String string, Object object) {  
        return null;  
    }  
  
    @Override  
    public void setActivityResultCallback(CordovaPlugin cordovaPlugin) {  
          
    }  
  
    @Override  
    public void startActivityForResult(CordovaPlugin plugin, Intent intent, int i) {  
          
    }    

}  

R.layout.main文件配置，不明白官方文档为什么写成res/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"
    >

<org.apache.cordova.CordovaWebView
    android:id="@+id/tutoriaView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>
</LinearLayout>