org.h2.store.fs

Class FileUtils

java.lang.Object

org.h2.store.fs.FileUtils

public class FileUtils
extends java.lang.Object

This utility class contains utility functions that use the file system abstraction.

Constructor Summary

Constructors

Constructor and Description
FileUtils()

Method Summary

Modifier and Type	Method and Description
static boolean	canWrite(java.lang.String fileName) Check if the file is writable.
static void	createDirectories(java.lang.String dir) Create the directory and all required parent directories.
static void	createDirectory(java.lang.String directoryName) Create a directory (all required parent directories must already exist).
static boolean	createFile(java.lang.String fileName) Create a new file.
static java.lang.String	createTempFile(java.lang.String prefix, java.lang.String suffix, boolean deleteOnExit, boolean inTempDir) Create a new temporary file.
static void	delete(java.lang.String path) Delete a file or directory if it exists.
static void	deleteRecursive(java.lang.String path, boolean tryOnly) Delete a directory or file and all subdirectories and files.
static boolean	exists(java.lang.String fileName) Checks if a file exists.
static java.lang.String	getName(java.lang.String path) Get the file or directory name (the last element of the path).
static java.lang.String	getParent(java.lang.String fileName) Get the parent directory of a file or directory.
static boolean	isAbsolute(java.lang.String fileName) Check if the file name includes a path.
static boolean	isDirectory(java.lang.String fileName) Check if it is a file or a directory.
static long	lastModified(java.lang.String fileName) Get the last modified date of a file.
static void	move(java.lang.String source, java.lang.String target) Rename a file if this is allowed.
static void	moveAtomicReplace(java.lang.String source, java.lang.String target) Rename a file if this is allowed, and try to atomically replace an existing file.
static java.util.List<java.lang.String>	newDirectoryStream(java.lang.String path) List the files and directories in the given directory.
static java.io.InputStream	newInputStream(java.lang.String fileName) Create an input stream to read from the file.
static java.io.OutputStream	newOutputStream(java.lang.String fileName, boolean append) Create an output stream to write into the file.
static java.nio.channels.FileChannel	open(java.lang.String fileName, java.lang.String mode) Open a random access file object.
static void	readFully(java.nio.channels.FileChannel channel, java.nio.ByteBuffer dst) Fully read from the file.
static boolean	setReadOnly(java.lang.String fileName) Disable the ability to write.
static long	size(java.lang.String fileName) Get the size of a file in bytes This method is similar to Java 7 java.nio.file.attribute.Attributes.
static java.lang.String	toRealPath(java.lang.String fileName) Get the canonical file or directory name.
static boolean	tryDelete(java.lang.String path) Try to delete a file or directory (ignoring errors).
static java.lang.String	unwrap(java.lang.String fileName) Get the unwrapped file name (without wrapper prefixes if wrapping / delegating file systems are used).
static void	writeFully(java.nio.channels.FileChannel channel, java.nio.ByteBuffer src) Fully write to the file.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileUtils

public FileUtils()

Method Detail

exists

public static boolean exists(java.lang.String fileName)

Checks if a file exists. This method is similar to Java 7 java.nio.file.Path.exists.

Parameters:

fileName - the file name

Returns:

true if it exists

createDirectory

public static void createDirectory(java.lang.String directoryName)

Create a directory (all required parent directories must already exist). This method is similar to Java 7 java.nio.file.Path.createDirectory.

Parameters:

directoryName - the directory name

createFile

public static boolean createFile(java.lang.String fileName)

Create a new file. This method is similar to Java 7 java.nio.file.Path.createFile, but returns false instead of throwing a exception if the file already existed.

Parameters:

fileName - the file name

Returns:

true if creating was successful

delete

public static void delete(java.lang.String path)

Delete a file or directory if it exists. Directories may only be deleted if they are empty. This method is similar to Java 7 java.nio.file.Path.deleteIfExists.

Parameters:

path - the file or directory name

toRealPath

public static java.lang.String toRealPath(java.lang.String fileName)

Get the canonical file or directory name. This method is similar to Java 7 java.nio.file.Path.toRealPath.

Parameters:

fileName - the file name

Returns:

the normalized file name

getParent

public static java.lang.String getParent(java.lang.String fileName)

Get the parent directory of a file or directory. This method returns null if there is no parent. This method is similar to Java 7 java.nio.file.Path.getParent.

Parameters:

fileName - the file or directory name

Returns:

the parent directory name

isAbsolute

public static boolean isAbsolute(java.lang.String fileName)

Check if the file name includes a path. This method is similar to Java 7 java.nio.file.Path.isAbsolute.

Parameters:

fileName - the file name

Returns:

if the file name is absolute

move

public static void move(java.lang.String source,
                        java.lang.String target)

Rename a file if this is allowed. This method is similar to Java 7 java.nio.file.Files.move.

Parameters:

source - the old fully qualified file name

target - the new fully qualified file name

moveAtomicReplace

public static void moveAtomicReplace(java.lang.String source,
                                     java.lang.String target)

Rename a file if this is allowed, and try to atomically replace an existing file. This method is similar to Java 7 java.nio.file.Files.move.

Parameters:

source - the old fully qualified file name

target - the new fully qualified file name

getName

public static java.lang.String getName(java.lang.String path)

Get the file or directory name (the last element of the path). This method is similar to Java 7 java.nio.file.Path.getName.

Parameters:

path - the directory and file name

Returns:

just the file name

newDirectoryStream

public static java.util.List<java.lang.String> newDirectoryStream(java.lang.String path)

List the files and directories in the given directory. This method is similar to Java 7 java.nio.file.Path.newDirectoryStream.

Parameters:

path - the directory

Returns:

the list of fully qualified file names

lastModified

public static long lastModified(java.lang.String fileName)

Get the last modified date of a file. This method is similar to Java 7 java.nio.file.attribute.Attributes. readBasicFileAttributes(file).lastModified().toMillis()

Parameters:

fileName - the file name

Returns:

the last modified date

size

public static long size(java.lang.String fileName)

Get the size of a file in bytes This method is similar to Java 7 java.nio.file.attribute.Attributes. readBasicFileAttributes(file).size()

Parameters:

fileName - the file name

Returns:

the size in bytes

isDirectory

public static boolean isDirectory(java.lang.String fileName)

Check if it is a file or a directory. java.nio.file.attribute.Attributes. readBasicFileAttributes(file).isDirectory()

Parameters:

fileName - the file or directory name

Returns:

true if it is a directory

open

public static java.nio.channels.FileChannel open(java.lang.String fileName,
                                                 java.lang.String mode)
                                          throws java.io.IOException

Open a random access file object. This method is similar to Java 7 java.nio.channels.FileChannel.open.

Parameters:

fileName - the file name

mode - the access mode. Supported are r, rw, rws, rwd

Returns:

the file object

Throws:

java.io.IOException

newInputStream

public static java.io.InputStream newInputStream(java.lang.String fileName)
                                          throws java.io.IOException

Create an input stream to read from the file. This method is similar to Java 7 java.nio.file.Path.newInputStream.

Parameters:

fileName - the file name

Returns:

the input stream

Throws:

java.io.IOException

newOutputStream

public static java.io.OutputStream newOutputStream(java.lang.String fileName,
                                                   boolean append)
                                            throws java.io.IOException

Create an output stream to write into the file. This method is similar to Java 7 java.nio.file.Path.newOutputStream.

Parameters:

fileName - the file name

append - if true, the file will grow, if false, the file will be truncated first

Returns:

the output stream

Throws:

java.io.IOException

canWrite

public static boolean canWrite(java.lang.String fileName)

Check if the file is writable. This method is similar to Java 7 java.nio.file.Path.checkAccess(AccessMode.WRITE)

Parameters:

fileName - the file name

Returns:

if the file is writable

setReadOnly

public static boolean setReadOnly(java.lang.String fileName)

Disable the ability to write. The file can still be deleted afterwards.

Parameters:

fileName - the file name

Returns:

true if the call was successful

unwrap

public static java.lang.String unwrap(java.lang.String fileName)

Get the unwrapped file name (without wrapper prefixes if wrapping / delegating file systems are used).

Parameters:

fileName - the file name

Returns:

the unwrapped

deleteRecursive

public static void deleteRecursive(java.lang.String path,
                                   boolean tryOnly)

Delete a directory or file and all subdirectories and files.

Parameters:

path - the path

tryOnly - whether errors should be ignored

createDirectories

public static void createDirectories(java.lang.String dir)

Create the directory and all required parent directories.

Parameters:

dir - the directory name

tryDelete

public static boolean tryDelete(java.lang.String path)

Try to delete a file or directory (ignoring errors).

Parameters:

path - the file or directory name

Returns:

true if it worked

createTempFile

public static java.lang.String createTempFile(java.lang.String prefix,
                                              java.lang.String suffix,
                                              boolean deleteOnExit,
                                              boolean inTempDir)
                                       throws java.io.IOException

Create a new temporary file.

Parameters:

prefix - the prefix of the file name (including directory name if required)

suffix - the suffix

deleteOnExit - if the file should be deleted when the virtual machine exists

inTempDir - if the file should be stored in the temporary directory

Returns:

the name of the created file

Throws:

java.io.IOException

readFully

public static void readFully(java.nio.channels.FileChannel channel,
                             java.nio.ByteBuffer dst)
                      throws java.io.IOException

Fully read from the file. This will read all remaining bytes, or throw an EOFException if not successful.

Parameters:

channel - the file channel

dst - the byte buffer

Throws:

java.io.IOException

writeFully

public static void writeFully(java.nio.channels.FileChannel channel,
                              java.nio.ByteBuffer src)
                       throws java.io.IOException

Fully write to the file. This will write all remaining bytes.

Parameters:

channel - the file channel

src - the byte buffer

Throws:

java.io.IOException