fr.maxcom.os.storage

Class VolumeManager

java.lang.Object

fr.maxcom.os.storage.VolumeManager

public class VolumeManager
extends Object

A volume manager.

The purpose of a volume manager is to access the Media Storage Directory of an Android device, as any other part of the file system. For each plugged-in USB device, you get a Volume object.

Emulation mode

When developing on a device without any USB connector or with a fewer number of connectors than the expected target, you can fake one or more existing ordinary internal directory as an additional Media Storage Directory containing emulated USB devices, with addMediaStorageDirectory().

In that directory, normal files are ignored but each directory simulates a mount point for a volume.

Optionally, these emulated volumes can be given a label with a special convention: store the label as a UTF-8 string in a file named .label located at the volume root. If this file is not present or if its contents is empty, the label defaults to the root folder name.

Examples

Here is a possible tree for one emulated Media Storage Directory having two USB devices:

/mnt/sdcard//Movies/
                   |_ usb.0000-0001/
                   |               |_ .label
                   |               |_ myVideo.mp4
                   |_ usb.E9D9-4932/
                                   |_ myOtherVideo.mp4

Here is a partial sample of usage in an application:

VolumeManager volumeManager = new VolumeManager();
volumeManager.addMediaStorageDirectory("/mnt/sdcard/Movies");
List<Volume> volumes = volumeManager.getVolumes();
for (Volume v: volumes) {
        Log.d(TAG, "volume label: " + v.getLabel());
}
 

Suppose there is an USB stick labeled Android and that the .label file contains MyLabel, here is the potential output:

volume label: Android
volume label: MyLabel
volume label: usb.E9D9-4932

Constructor Summary

Constructors

Constructor and Description
VolumeManager() Default constructor.

Method Summary

Modifier and Type	Method and Description
boolean	addMediaStorageDirectory(File directory) Adds an emulated Media Storage Directory where looking for volumes.
boolean	addMediaStorageDirectory(String pathname) Adds an emulated Media Storage Directory where looking for volumes.
List<Volume>	getVolumes() Returns the list of currently mounted volumes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VolumeManager

public VolumeManager()

Default constructor.

Method Detail

addMediaStorageDirectory

public boolean addMediaStorageDirectory(String pathname)

Adds an emulated Media Storage Directory where looking for volumes. May be called more than once and is fine even if the directory is already registered.

Parameters:

pathname - The pathname to a directory hosting emulated volumes.

Returns:

true if the pathname designates an existing file and this file is a directory.

See Also:

Emulation mode

addMediaStorageDirectory

public boolean addMediaStorageDirectory(File directory)

Adds an emulated Media Storage Directory where looking for volumes. May be called more than once and is fine even if the directory is already registered.

Parameters:

directory - The directory hosting emulated volumes.

Returns:

true if the argument designates an existing file and this file is a directory.

See Also:

Emulation mode

getVolumes

public List<Volume> getVolumes()

Returns the list of currently mounted volumes. A volume may be physical or emulated.

Returns:

A list of volumes, possibly empty.