android.content.res
Class AssetFileDescriptor

java.lang.Object
  android.content.res.AssetFileDescriptor

All Implemented Interfaces:

Parcelable

public class AssetFileDescriptor
extends Object
implements Parcelable

File descriptor of an entry in the AssetManager. This provides your own opened FileDescriptor that can be used to read the data, as well as the offset and length of that entry's data in the file.

Nested Class Summary

static class	AssetFileDescriptor.AutoCloseInputStream An InputStream you can create on a ParcelFileDescriptor, which will take care of calling ParcelFileDescritor.close() for you when the stream is closed.
static class	AssetFileDescriptor.AutoCloseOutputStream An OutputStream you can create on a ParcelFileDescriptor, which will take care of calling ParcelFileDescritor.close() for you when the stream is closed.

Nested classes/interfaces inherited from interface android.os.Parcelable

Parcelable.Creator<T>

Field Summary

static Parcelable.Creator<AssetFileDescriptor>	CREATOR
static long	UNKNOWN_LENGTH Length used with AssetFileDescriptor(ParcelFileDescriptor, long, long) and getDeclaredLength() when a length has not been declared.

Fields inherited from interface android.os.Parcelable

CONTENTS_FILE_DESCRIPTOR, PARCELABLE_WRITE_RETURN_VALUE

Constructor Summary

AssetFileDescriptor(Parcel src)

AssetFileDescriptor(ParcelFileDescriptor fd, long startOffset, long length)
Create a new AssetFileDescriptor from the given values.

Method Summary

void	close() Convenience for calling getParcelFileDescriptor().close().
FileInputStream	createInputStream() Create and return a new auto-close input stream for this asset.
FileOutputStream	createOutputStream() Create and return a new auto-close output stream for this asset.
int	describeContents() Describe the kinds of special objects contained in this Parcelable's marshalled representation.
static AssetFileDescriptor	fromMemoryFile(MemoryFile memoryFile) Creates an AssetFileDescriptor from a memory file.
long	getDeclaredLength() Return the actual number of bytes that were declared when the AssetFileDescriptor was constructed.
FileDescriptor	getFileDescriptor() Returns the FileDescriptor that can be used to read the data in the file.
long	getLength() Returns the total number of bytes of this asset entry's data.
ParcelFileDescriptor	getParcelFileDescriptor() The AssetFileDescriptor contains its own ParcelFileDescriptor, which in addition to the normal FileDescriptor object also allows you to close the descriptor when you are done with it.
long	getStartOffset() Returns the byte offset where this asset entry's data starts.
String	toString() Returns a string containing a concise, human-readable description of this object.
void	writeToParcel(Parcel out, int flags) Flatten this object in to a Parcel.

Methods inherited from class java.lang.Object

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

Field Detail

UNKNOWN_LENGTH

public static final long UNKNOWN_LENGTH

Length used with AssetFileDescriptor(ParcelFileDescriptor, long, long) and getDeclaredLength() when a length has not been declared. This means the data extends to the end of the file.

See Also:

Constant Field Values

CREATOR

public static final Parcelable.Creator<AssetFileDescriptor> CREATOR

Constructor Detail

AssetFileDescriptor

public AssetFileDescriptor(ParcelFileDescriptor fd,
                           long startOffset,
                           long length)

Create a new AssetFileDescriptor from the given values.

Parameters:

fd - The underlying file descriptor.

startOffset - The location within the file that the asset starts. This must be 0 if length is UNKNOWN_LENGTH.

length - The number of bytes of the asset, or {@link #UNKNOWN_LENGTH if it extends to the end of the file.

AssetFileDescriptor

AssetFileDescriptor(Parcel src)

Method Detail

getParcelFileDescriptor

public ParcelFileDescriptor getParcelFileDescriptor()

The AssetFileDescriptor contains its own ParcelFileDescriptor, which in addition to the normal FileDescriptor object also allows you to close the descriptor when you are done with it.

getFileDescriptor

public FileDescriptor getFileDescriptor()

Returns the FileDescriptor that can be used to read the data in the file.

getStartOffset

public long getStartOffset()

Returns the byte offset where this asset entry's data starts.

getLength

public long getLength()

Returns the total number of bytes of this asset entry's data. May be UNKNOWN_LENGTH if the asset extends to the end of the file. If the AssetFileDescriptor was constructed with UNKNOWN_LENGTH, this will use ParcelFileDescriptor.getStatSize() to find the total size of the file, returning that number if found or UNKNOWN_LENGTH if it could not be determined.

See Also:

getDeclaredLength()

getDeclaredLength

public long getDeclaredLength()

Return the actual number of bytes that were declared when the AssetFileDescriptor was constructed. Will be UNKNOWN_LENGTH if the length was not declared, meaning data should be read to the end of the file.

See Also:

getDeclaredLength()

close

public void close()
           throws IOException

Convenience for calling getParcelFileDescriptor().close().

Throws:

IOException

createInputStream

public FileInputStream createInputStream()
                                  throws IOException

Create and return a new auto-close input stream for this asset. This will either return a full asset AssetFileDescriptor.AutoCloseInputStream, or an underlying ParcelFileDescriptor.AutoCloseInputStream depending on whether the the object represents a complete file or sub-section of a file. You should only call this once for a particular asset.

Throws:

IOException

createOutputStream

public FileOutputStream createOutputStream()
                                    throws IOException

Create and return a new auto-close output stream for this asset. This will either return a full asset AssetFileDescriptor.AutoCloseOutputStream, or an underlying ParcelFileDescriptor.AutoCloseOutputStream depending on whether the the object represents a complete file or sub-section of a file. You should only call this once for a particular asset.

Throws:

IOException

toString

public String toString()

Description copied from class: Object

Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:

   getClass().getName() + '@' + Integer.toHexString(hashCode())

See Writing a useful toString method if you intend implementing your own toString method.

Overrides:

toString in class Object

Returns:

a printable representation of this object.

describeContents

public int describeContents()

Description copied from interface: Parcelable

Describe the kinds of special objects contained in this Parcelable's marshalled representation.

Specified by:

describeContents in interface Parcelable

Returns:

a bitmask indicating the set of special object types marshalled by the Parcelable.

writeToParcel

public void writeToParcel(Parcel out,
                          int flags)

Description copied from interface: Parcelable

Flatten this object in to a Parcel.

Specified by:

writeToParcel in interface Parcelable

Parameters:

out - The Parcel in which the object should be written.

flags - Additional flags about how the object should be written. May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE.

fromMemoryFile

public static AssetFileDescriptor fromMemoryFile(MemoryFile memoryFile)
                                          throws IOException

Creates an AssetFileDescriptor from a memory file.

Throws:

IOException