com.lf.commons.io

Class FileTypeFactory

java.lang.Object

com.lf.commons.lang.ManagedFactory

com.lf.commons.io.FileTypeFactory

All Implemented Interfaces:

TypeProvider

public class FileTypeFactory
extends ManagedFactory
implements TypeProvider

Factory class for vending various objects (here of type Hashtable).

Whenever possible, this factory will hand out references to shared instances. Use this if you need many, many file types objects while running your application and it is acceptable for you to continously use a certain amount of memory for the cached object. If you only use instances once then you should either install an object as usual (by calling new), or let this factory create a shared instance and flush the factory after you're finished with the object. The garbage collector will then release memory on-the-fly as the objects are no longer referenced so the overall memory footprint can be very small.

You can pass either File or FileObject objects to be checked here. A temporary directory with exclusive access is needed to get the system file types for URLs. Whenever a network resource is processed, a local file is being renamed and the respective value is requested from the FileSystemView class.

If a temporary directory is specified then also non-existing local file references can be checked with this class which is not possible when using FileSystemView.

Since:

1.6

Version:

$Revision: 1.3 $, $Date: 2012/12/28 11:44:25 $

Author:

Axel Schwolow

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	caching Put file data into fast (managed) cache (enabled by default)?
protected static FileTypeFactory	sharedInstance Shared FileTypeFactory instance.
protected java.io.File	tempdir Temporary directory to simulate local files (optional).

Fields inherited from class com.lf.commons.lang.ManagedFactory

cacheObjectByID

Fields inherited from interface com.lf.commons.io.TypeProvider

KEY_DISPLAY_NAME, KEY_ICON, KEY_TYPE_DESCRIPTION

Constructor Summary

Constructors

Constructor and Description
FileTypeFactory() Constructs an instance of this factory.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canRelease(java.lang.String id) Checks whether a factory shared object can be released or not.
void	cleanup(java.lang.String id) Perform optional cleanup tasks like closing database connections or disposing dialogs.
protected java.io.File	createTemporaryFile(java.lang.Object resource) Tries to create a local file named after the given resource.
java.lang.String	getDisplayName(java.lang.Object resource) Provides the display name of the given resource.
javax.swing.Icon	getIcon(java.lang.Object resource) Provides the icon of the given resource.
java.util.Hashtable<java.lang.String,java.lang.Object>	getInfo(java.lang.Object resource) Provides the info on the given resource.
static FileTypeFactory	getSharedInstance() Provides the shared instance of the factory implementation.
java.io.File	getTemporaryDirectory() Provides the temporary directory..
java.lang.String	getTypeDescription(java.lang.Object resource) Provides the type description of the given resource.
java.lang.Object	request(java.lang.String id) Create the factory shared object, recycle if already existing.
void	setCaching(boolean enable) Enables caching (enabled by default).
void	setTemporaryDirectory(java.io.File tempdir) Constructor method setting the temporary directory for network file simulation.

Methods inherited from class com.lf.commons.lang.ManagedFactory

getRegisteredObjects, hasSharedInstance, release, releaseByStrategy, releaseForced, set

Methods inherited from class java.lang.Object

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

Field Detail

sharedInstance

protected static FileTypeFactory sharedInstance

Shared FileTypeFactory instance.

tempdir

protected java.io.File tempdir

Temporary directory to simulate local files (optional).

caching

protected boolean caching

Put file data into fast (managed) cache (enabled by default)?

Constructor Detail

FileTypeFactory

public FileTypeFactory()

Constructs an instance of this factory.

Since:

1.6

Method Detail

getSharedInstance

public static FileTypeFactory getSharedInstance()

Provides the shared instance of the factory implementation.

Returns:

Shared instance of the factory

Since:

1.6

setTemporaryDirectory

public void setTemporaryDirectory(java.io.File tempdir)

Constructor method setting the temporary directory for network file simulation.

Parameters:

tempdir - Temporary directory

Throws:

java.lang.NullPointerException - Error indication

java.lang.IllegalArgumentException - Error indication

Since:

1.6

getTemporaryDirectory

public java.io.File getTemporaryDirectory()

Provides the temporary directory..

Returns:

The directory, null if not available

Since:

1.6

setCaching

public void setCaching(boolean enable)

Enables caching (enabled by default).

Parameters:

enable - The state

Since:

1.6

request

public java.lang.Object request(java.lang.String id)

Create the factory shared object, recycle if already existing.

This method can only be done by the sub classes since every shared object can have its own specialities needed for creation. Here, the caching mechanism may be deactivated by calling setCaching(false).

Specified by:

request in class ManagedFactory

Parameters:

id - The factory-unique identifier of the shared object

Returns:

The shared object, null if none could be created

Since:

1.6

canRelease

public boolean canRelease(java.lang.String id)

Checks whether a factory shared object can be released or not.

Specified by:

canRelease in class ManagedFactory

Parameters:

id - The factory-unique identifier of the shared object

Returns:

Can the object be released according to the factories needs?

Since:

1.6

cleanup

public void cleanup(java.lang.String id)

Perform optional cleanup tasks like closing database connections or disposing dialogs.

Specified by:

cleanup in class ManagedFactory

Parameters:

id - The factory-unique identifier of the shared object

Since:

1.6

createTemporaryFile

protected java.io.File createTemporaryFile(java.lang.Object resource)

Tries to create a local file named after the given resource.

This method creates temporary files of zero-length for both File and FileObject objects.

Parameters:

resource - The resource

Returns:

The icon, null if not available

Since:

1.6

getDisplayName

public java.lang.String getDisplayName(java.lang.Object resource)

Provides the display name of the given resource.

Specified by:

getDisplayName in interface TypeProvider

Parameters:

resource - The resource

Returns:

The name, null if not available

Since:

1.6

getTypeDescription

public java.lang.String getTypeDescription(java.lang.Object resource)

Provides the type description of the given resource.

Specified by:

getTypeDescription in interface TypeProvider

Parameters:

resource - The resource

Returns:

The type, null if not available

Since:

1.6

getIcon

public javax.swing.Icon getIcon(java.lang.Object resource)

Provides the icon of the given resource.

Specified by:

getIcon in interface TypeProvider

Parameters:

resource - The resource

Returns:

The icon, null if not available

Since:

1.6

getInfo

public java.util.Hashtable<java.lang.String,java.lang.Object> getInfo(java.lang.Object resource)

Provides the info on the given resource.

Here, only one single temporary file is created to get all the available resource info.

Specified by:

getInfo in interface TypeProvider

Parameters:

resource - The resource

Returns:

The value container, empty if not available

Since:

1.6