Module com.aoapps.tempfiles

Package com.aoapps.tempfiles

Class TempFileContext

java.lang.Object

com.aoapps.tempfiles.TempFileContext

All Implemented Interfaces:

Closeable, AutoCloseable

public class TempFileContext
extends Object
implements Closeable

Provides a central temporary file manager for use by any number of projects. The temporary files are optionally deleted on shutdown using shutdown hooks. The shutdown-registered temporary files are also immediately deleted when the last instance is closed.

Thread-safe with fine-grained locking.

Constructor Summary

Constructors

Constructor	Description
TempFileContext()	Uses the system default temporary directory from system property "java.io.tmpdir".
TempFileContext(File tmpDir)	Create a new instance of the temp file manager.
TempFileContext(String tmpDir)	Uses the provided temporary directory.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this instance.
TempFile	createTempDirectory()	Creates a new temporary directory with default prefix, recursively deleting on close or exit.
TempFile	createTempDirectory(String prefix)	Creates a new temporary directory with the given prefix, recursively deleting on close or exit.
TempFile	createTempFile()	Creates a new temporary file with default prefix and suffix, deleting on close or exit.
TempFile	createTempFile(String name)	Creates a new temporary file based on the given name, deleting on close or exit.
TempFile	createTempFile(String prefix, String suffix)	Creates a new temporary file with the given prefix and suffix, deleting on close or exit.
static String	generatePrefix(String template)	Generates a temp file prefix given a name template.
int	getSize()	Gets the number of files that are currently scheduled to be deleted on close/exit.
File	getTmpDir()	Gets the temporary directory this instance is using.

Methods inherited from class java.lang.Object

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

Constructor Detail

TempFileContext

public TempFileContext(File tmpDir)

Create a new instance of the temp file manager. close() must be called when done with the instance. This should be done in a try-with-resources, try-finally, or strong equivalent, such as Servlet.destroy().

Shutdown hooks are shared between instances.

Parameters:

tmpDir - The temporary directory or null to use the system default

See Also:

close()

TempFileContext

public TempFileContext(String tmpDir)

Uses the provided temporary directory.

Parameters:

tmpDir - The temporary directory or null to use the system default

See Also:

TempFileContext(java.io.File)

TempFileContext

public TempFileContext()

Uses the system default temporary directory from system property "java.io.tmpdir".

See Also:

getSystemTmpDir(), TempFileContext(java.io.File)

Method Detail

getTmpDir

public File getTmpDir()

Gets the temporary directory this instance is using.

generatePrefix

public static String generatePrefix(String template)

Generates a temp file prefix given a name template.

1. If null or String.isEmpty(), "tmp_" is used.
2. Any character that is not in [a-zA-Z0-9.-_] is converted to '_'.
3. If less than MIN_PREFIX_LENGTH, padded with trailing '_' to a length of MIN_PREFIX_LENGTH.
4. If greater than MAX_PREFIX_LENGTH characters, is truncated to a length of MAX_PREFIX_LENGTH.

Parameters:

template - the name of the temporary file that will be filtered for only safe characters

createTempDirectory

public TempFile createTempDirectory(String prefix)
                             throws IllegalStateException,
                                    IOException

Creates a new temporary directory with the given prefix, recursively deleting on close or exit.

Parameters:

prefix - If null or String.isEmpty(), "tmp_" is used. If less than MIN_PREFIX_LENGTH, padded with trailing '_' to a length of MIN_PREFIX_LENGTH. If greater than MAX_PREFIX_LENGTH characters, is truncated to a length of MAX_PREFIX_LENGTH.

Throws:

IllegalStateException - if already closed

IOException

createTempDirectory

public TempFile createTempDirectory()
                             throws IllegalStateException,
                                    IOException

Creates a new temporary directory with default prefix, recursively deleting on close or exit.

Throws:

IllegalStateException - if already closed

IOException

createTempFile

public TempFile createTempFile(String prefix,
                               String suffix)
                        throws IllegalStateException,
                               IOException

Creates a new temporary file with the given prefix and suffix, deleting on close or exit.

Parameters:

prefix - If null or String.isEmpty(), "tmp_" is used. If less than MIN_PREFIX_LENGTH, padded with trailing '_' to a length of MIN_PREFIX_LENGTH. If greater than MAX_PREFIX_LENGTH characters, is truncated to a length of MAX_PREFIX_LENGTH.

suffix - when null, ".tmp" is used.

Throws:

IllegalStateException - if already closed

IOException

createTempFile

public TempFile createTempFile(String name)
                        throws IllegalStateException,
                               IOException

Creates a new temporary file based on the given name, deleting on close or exit.

When the file contains a dot ('.') followed by only the characters in [a-zA-Z0-9_], and the dot is not the first character, it is used as the temp file suffix (to maintain file type by extension). Multiple extensions are supported, such as used by "filename.tar.gz".

When the suffix is removed from the name, the prefix is followed by an underscore ('_') separator.

When no automatic suffix is determine, defaults to ".tmp".

Throws:

IllegalStateException - if already closed

IOException

createTempFile

public TempFile createTempFile()
                        throws IllegalStateException,
                               IOException

Creates a new temporary file with default prefix and suffix, deleting on close or exit.

Throws:

IllegalStateException - if already closed

IOException

getSize

public int getSize()

Gets the number of files that are currently scheduled to be deleted on close/exit.

close

public void close()
           throws IOException

Closes this instance. Once closed, no additional temp files may be managed. Any overriding method must call super.close().

If this is the last active instance, the underlying shutdown hook is also removed.

If already closed, no action will be taken and no exception thrown.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException