Package com.sleepycat.db

Class DatabaseStream

java.lang.Object

com.sleepycat.db.DatabaseStream

public class DatabaseStream
extends java.lang.Object

A database stream. The database stream is used to access external files.

Once the database stream close method has been called, the handle may not be accessed again.

To obtain a database stream with default attributes:

    DatabaseStream dbs = myCursor.openDatabaseStream(null);

To customize the attributes of a database stream, use a DatabaseStreamConfig object.

    DatabaseStreamConfig config = new DatabaseStreamConfig();
    config.setReadOnly(true);
    DatabaseStream dbs = myCursor.openDatabaseStream(config);

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DatabaseStream(Cursor cursor, DatabaseStreamConfig config)

Method Summary

Modifier and Type	Method	Description
void	close()	Discard the database stream.
DatabaseStreamConfig	getConfig()	Return this database stream configuration.
Cursor	getCursor()	Return the Cursor handle associated with this database stream.
OperationStatus	read(DatabaseEntry data, long offset, int size)	Read from the external file accessed by this database stream.
long	size()	Return the size in bytes of the external file accessed by the database stream.
OperationStatus	write(DatabaseEntry data, long offset)	Write to the external file accessed by the database stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseStream

protected DatabaseStream(Cursor cursor,
                         DatabaseStreamConfig config)

Method Detail

close

public void close()
           throws DatabaseException

Discard the database stream.

After the close method has been called, you cannot use the database stream handle again.

It is recommended to always close all database stream handles immediately after their use to release resources.

Throws:

DatabaseException - if a failure occurs.

getConfig

public DatabaseStreamConfig getConfig()

Return this database stream configuration.

Returns:

This database stream configuration.

getCursor

public Cursor getCursor()

Return the Cursor handle associated with this database stream.

Returns:

The cursor handle associated with this database stream.

read

public OperationStatus read(DatabaseEntry data,
                            long offset,
                            int size)
                     throws DatabaseException,
                            java.lang.IllegalArgumentException

Read from the external file accessed by this database stream.

Parameters:

data - the data read from the file returned as output. Its byte array does not need to be initialized by the caller.

offset - the position in bytes in the file where the reading starts.

size - the number of bytes to read.

Returns:

OperationStatus.SUCCESS if the operation succeeds.

Throws:

java.lang.IllegalArgumentException - if a failure occurs.

java.lang.IllegalArgumentException - if the operation fails.

DatabaseException - if a failure occurs.

size

public long size()
          throws DatabaseException

Return the size in bytes of the external file accessed by the database stream.

Returns:

The size in bytes of the file accessed by the database stream.

Throws:

DatabaseException - if a failure occurs.

write

public OperationStatus write(DatabaseEntry data,
                             long offset)
                      throws DatabaseException,
                             java.lang.IllegalArgumentException

Write to the external file accessed by the database stream.

Parameters:

data - the data DatabaseEntry to write into the file.

offset - the position in bytes in the file where the writing starts.

Returns:

OperationStatus.SUCCESS if the operation succeeds.

Throws:

java.lang.IllegalArgumentException - if the operation fails.

DatabaseException - if a failure occurs.