File	Doc	Category	Size	Date	Package
BackupDataInput.java	API Doc	Android 5.1 API	7652	Thu Mar 12 22:22:10 GMT 2015	android.app.backup

BackupDataInput

• java.lang.Object

public void onRestore(BackupDataInput data, int appVersionCode,
ParcelFileDescriptor newState) {
while (data.readNextHeader()) {
String key = data.getKey();
int dataSize = data.getDataSize();

if (key.equals(MY_BACKUP_KEY_ONE)) {
// process this kind of record here
byte[] buffer = new byte[dataSize];
data.readEntityData(buffer, 0, dataSize); // reads the entire entity at once

// now 'buffer' holds the raw data and can be processed however
// the agent wishes
processBackupKeyOne(buffer);
} else if (key.equals(MY_BACKUP_KEY_TO_IGNORE) {
// a key we recognize but wish to discard
data.skipEntityData();
} // ... etc.
}
}

Fields Summary
long	mBackupReader
private EntityHeader	mHeader
private boolean	mHeaderReady

Constructors Summary
public BackupDataInput(FileDescriptor fd) hide if (fd == null) throw new NullPointerException(); mBackupReader = ctor(fd); if (mBackupReader == 0) { throw new RuntimeException("Native initialization failed with fd=" + fd); }

Methods Summary
private static native long	ctor(java.io.FileDescriptor fd)
private static native void	dtor(long mBackupReader)
protected void	finalize() hide try { dtor(mBackupReader); } finally { super.finalize(); }
public int	getDataSize() Report the size in bytes of the data associated with the current entity in the restore stream. return The size of the record's raw data, in bytes throws IllegalStateException if the next record header has not yet been read if (mHeaderReady) { return mHeader.dataSize; } else { throw new IllegalStateException("Entity header not read"); }
public java.lang.String	getKey() Report the key associated with the current entity in the restore stream return the current entity's key string throws IllegalStateException if the next record header has not yet been read if (mHeaderReady) { return mHeader.key; } else { throw new IllegalStateException("Entity header not read"); }
public int	readEntityData(byte[] data, int offset, int size) Read a record's raw data from the restore stream. The record's header must first have been processed by the {@link #readNextHeader()} method. Multiple calls to this method may be made in order to process the data in chunks; not all of it must be read in a single call. Once all of the raw data for the current entity has been read, further calls to this method will simply return zero. param data An allocated byte array of at least 'size' bytes param offset Offset within the 'data' array at which the data will be placed when read from the stream param size The number of bytes to read in this pass return The number of bytes of data read. Once all of the data for this entity has been read, further calls to this method will return zero. throws IOException if an error occurred when trying to read the restore data stream if (mHeaderReady) { int result = readEntityData_native(mBackupReader, data, offset, size); if (result >= 0) { return result; } else { throw new IOException("result=0x" + Integer.toHexString(result)); } } else { throw new IllegalStateException("Entity header not read"); }
private native int	readEntityData_native(long mBackupReader, byte[] data, int offset, int size)
public boolean	readNextHeader() Extract the next entity header from the restore stream. After this method return success, the {@link #getKey()} and {@link #getDataSize()} methods can be used to inspect the entity that is now available for processing. return true when there is an entity ready for consumption from the restore stream, false if the restore stream has been fully consumed. throws IOException if an error occurred while reading the restore stream int result = readNextHeader_native(mBackupReader, mHeader); if (result == 0) { // read successfully mHeaderReady = true; return true; } else if (result > 0) { // done mHeaderReady = false; return false; } else { // error mHeaderReady = false; throw new IOException("failed: 0x" + Integer.toHexString(result)); }
private native int	readNextHeader_native(long mBackupReader, android.app.backup.BackupDataInput$EntityHeader entity)
public void	skipEntityData() Consume the current entity's data without extracting it into a buffer for further processing. This allows a {@link android.app.backup.BackupAgent} to efficiently discard obsolete or otherwise uninteresting records during the restore operation. throws IOException if an error occurred when trying to read the restore data stream if (mHeaderReady) { skipEntityData_native(mBackupReader); } else { throw new IllegalStateException("Entity header not read"); }
private native int	skipEntityData_native(long mBackupReader)