Package net.sf.jasperreports.engine.fill

Class JRFileVirtualizer

java.lang.Object

net.sf.jasperreports.engine.fill.JRAbstractLRUVirtualizer

net.sf.jasperreports.engine.fill.JRFileVirtualizer

All Implemented Interfaces:

JRVirtualizer

public class JRFileVirtualizer
extends JRAbstractLRUVirtualizer

Virtualizes data to the filesystem. When this object is finalized, it removes the swap files it makes. The virtualized objects have references to this object, so finalization does not occur until this object and the objects using it are only weakly referenced.

Author:

John Bindel

Nested Class Summary

Nested classes/interfaces inherited from class net.sf.jasperreports.engine.fill.JRAbstractLRUVirtualizer

JRAbstractLRUVirtualizer.Cache, JRAbstractLRUVirtualizer.CacheReference

Field Summary

Fields

Modifier and Type	Field	Description
static final String	PROPERTY_TEMP_FILES_SET_DELETE_ON_EXIT	Property used to decide whether deleteOnExit should be requested for temporary files created by the virtualizer.

Fields inherited from class net.sf.jasperreports.engine.fill.JRAbstractLRUVirtualizer

lastObjectMap, lastObjectRef, lastObjectSet, pagedIn, pagedOut, serializer

Constructor Summary

Constructors

Constructor	Description
JRFileVirtualizer(int maxSize)	Uses the process's working directory as the location to store files.
JRFileVirtualizer(int maxSize, String directory)
JRFileVirtualizer(JasperReportsContext jasperReportsContext, int maxSize, String directory)

Method Summary

Modifier and Type	Method	Description
void	cleanup()	Called when we are done with the virtualizer and wish to cleanup any resources it has.
protected void	dispose(String virtualId)	Removes the external data associated with a virtualizable object.
protected void	pageIn(JRVirtualizable o)	Reads a virtualizable object's data from an external storage.
protected void	pageOut(JRVirtualizable o)	Writes a virtualizable object's data to an external storage.

Methods inherited from class net.sf.jasperreports.engine.fill.JRAbstractLRUVirtualizer

clearData, contextChanged, deregisterObject, dispose, disposeAll, evict, finalize, isEvictable, isPagedOut, isPagedOutAndTouch, isReadOnly, isReadOnly, lastObject, readData, registerObject, requestData, reset, setLastObject, setReadOnly, touch, virtualizeData, writeData

Methods inherited from class java.lang.Object

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

Field Details

PROPERTY_TEMP_FILES_SET_DELETE_ON_EXIT

public static final String PROPERTY_TEMP_FILES_SET_DELETE_ON_EXIT

Property used to decide whether deleteOnExit should be requested for temporary files created by the virtualizer.

Calling File.deleteOnExit() will accumulate JVM process memory (see this bug), and this should abviously be avoided in long-running applications.

Temporary files will be deleted by explicitly calling cleanup() or from the virtualizer finalize() method.

See Also:

• Constant Field Values

Constructor Details

JRFileVirtualizer

public JRFileVirtualizer(int maxSize)

Uses the process's working directory as the location to store files.

Parameters:

maxSize - the maximum size (in JRVirtualizable objects) of the paged in cache.

JRFileVirtualizer

public JRFileVirtualizer(int maxSize,
 String directory)

Parameters:

maxSize - the maximum size (in JRVirtualizable objects) of the paged in cache.

directory - the base directory in the filesystem where the paged out data is to be stored

JRFileVirtualizer

public JRFileVirtualizer(JasperReportsContext jasperReportsContext,
 int maxSize,
 String directory)

Parameters:

jasperReportsContext - the JasperReportsContext to use for reading configuration from.

maxSize - the maximum size (in JRVirtualizable objects) of the paged in cache.

directory - the base directory in the filesystem where the paged out data is to be stored

Method Details

pageOut

protected void pageOut(JRVirtualizable o)
                throws IOException

Description copied from class: JRAbstractLRUVirtualizer

Writes a virtualizable object's data to an external storage.

Specified by:

pageOut in class JRAbstractLRUVirtualizer

Parameters:

o - a virtualizable object

Throws:

IOException

pageIn

protected void pageIn(JRVirtualizable o)
               throws IOException

Description copied from class: JRAbstractLRUVirtualizer

Reads a virtualizable object's data from an external storage.

Specified by:

pageIn in class JRAbstractLRUVirtualizer

Parameters:

o - a virtualizable object

Throws:

IOException

dispose

protected void dispose(String virtualId)

Description copied from class: JRAbstractLRUVirtualizer

Removes the external data associated with a virtualizable object.

Specified by:

dispose in class JRAbstractLRUVirtualizer

Parameters:

virtualId - the ID of the virtualizable object

cleanup

public void cleanup()

Called when we are done with the virtualizer and wish to cleanup any resources it has.