Android File(packed in Application)

We sometimes use file in Android Application.
In that case, we save file into application. Where is it?

Location

We have 2 choices to save file by default.

• res/raw
• assets

Several people explain between 2. So I don’t need additional description about them.

Basically, we use assets, but in case of using sound file or image resource to manage by R.java,
you need to use res/raw.

** res/raw is not existed by default. make it!**

** To manage file in those directory, we can get InputStream only, can’t get File class**

Samples

readFromAssets reads file from assets directory
readFromRaw reads file from res/raw

I saved test1.txt in res/raw, test2.txt in assets

public class ApplicationFileActivity extends Activity 
{
	private static String TAG = "Application File";
	
	@Override
	protected void onCreate(Bundle savedInstanceState) 
	{
		super.onCreate(savedInstanceState);
		
		readFromAssets();
		readFromRaw();
		
		new FileOperations(this).readFromAssets();
	}
	
	private void readFromAssets()
	{
		AssetManager as = getResources().getAssets();
		BufferedReader br = null;
		try
		{
			InputStream in = as.open("test2.txt");
			br = new BufferedReader(new InputStreamReader(in));
			String line;
			Log.i(TAG, "Assets");
			while ( (line = br.readLine()) != null )
			{
				Log.i(TAG, line);
			}
		}
		catch ( IOException oops )
		{
			oops.printStackTrace();
		}
		finally
		{
			if ( br != null )
			{
				try
				{
					br.close();
				}
				catch(IOException oops )
				{
					oops.printStackTrace();
				}
			}
		}
	}
	
	private void readFromRaw()
	{
		InputStream in = getResources().openRawResource(R.raw.test);	// test.txt
		BufferedReader br = new BufferedReader(new InputStreamReader(in));
		String line;
		try
		{
			Log.i(TAG, "Raw");
			while ( (line = br.readLine()) != null )
			{
				Log.i(TAG, line);
			}
		}
		catch ( IOException oops )
		{
			oops.printStackTrace();
		}
		finally
		{
			if ( br != null )
			{
				try
				{
					br.close();
				}
				catch(IOException oops )
				{
					oops.printStackTrace();
				}
			}
		}
	}
}

Sample2 Use Context

public class FileOperations 
{
	private static String TAG = "File Operations";
	
	Context context;
	
	public FileOperations ( Context context )
	{
		this.context = context;
	}
	
	public void readFromAssets()
	{
		AssetManager as = context.getResources().getAssets();
		BufferedReader br = null;
		try
		{
			InputStream in = as.open("test2.txt");
			br = new BufferedReader(new InputStreamReader(in));
			String line;
			Log.i(TAG, "Assets");
			while ( (line = br.readLine()) != null )
			{
				Log.i(TAG, line);
			}
		}
		catch ( IOException oops )
		{
			oops.printStackTrace();
		}
		finally
		{
			if ( br != null )
			{
				try
				{
					br.close();
				}
				catch(IOException oops )
				{
					oops.printStackTrace();
				}
			}
		}
	}
	
	public void readFromRaw()
	{
		InputStream in = context.getResources().openRawResource(R.raw.test);	// test.txt
		BufferedReader br = new BufferedReader(new InputStreamReader(in));
		String line;
		try
		{
			Log.i(TAG, "Raw");
			while ( (line = br.readLine()) != null )
			{
				Log.i(TAG, line);
			}
		}
		catch ( IOException oops )
		{
			oops.printStackTrace();
		}
		finally
		{
			if ( br != null )
			{
				try
				{
					br.close();
				}
				catch(IOException oops )
				{
					oops.printStackTrace();
				}
			}
		}
	}
}

To call this from Activity,

new FileOperations(this).readFromAssets();

Problem

Basically, these directory is managed by android.content.Context.
We can’t get file path and can’t get File class.
We can get only InputStream.