Package org.apache.directory.api.util

Class FileUtils

java.lang.Object

org.apache.directory.api.util.FileUtils

public final class FileUtils
extends Object

This code comes from Apache commons.io library. Origin of code: Excalibur, Alexandria, Tomcat, Commons-Utils.

Author:

Apache Directory Project

Field Summary

Fields

Modifier and Type	Field	Description
static long	ONE_KB	The number of bytes in a kilobyte.
static long	ONE_MB	The number of bytes in a megabyte.

Method Summary

Modifier and Type	Method	Description
static void	cleanDirectory(File directory)	Deletes a directory recursively.
static void	deleteDirectory(File directory)	Deletes a directory recursively.
static boolean	deleteQuietly(File file)	Deletes a file, never throwing an exception.
static void	forceDelete(File file)	Deletes a file.
static File	getTempDirectory()	Returns a File representing the system temporary directory.
static String	getTempDirectoryPath()	Returns the path to the system temporary directory.
static boolean	isSymlink(File file)	Determines whether the specified file is a Symbolic Link rather than an actual file.
static InputStream	openInputStream(File file)	Opens a FileInputStream for the specified file, providing better error messages than simply calling new FileInputStream(file).
static OutputStream	openOutputStream(File file)	Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.
static OutputStream	openOutputStream(File file, boolean append)	Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.
static byte[]	readFileToByteArray(File file)	Reads the contents of a file into a byte array.
static String	readFileToString(File file)	Deprecated. 2.5 use readFileToString(File, Charset) instead
static String	readFileToString(File file, String encoding)	Reads the contents of a file into a String.
static String	readFileToString(File file, Charset encoding)	Reads the contents of a file into a String.
static List<String>	readLines(File file)	Deprecated. 2.5 use readLines(File, Charset) instead
static List<String>	readLines(File file, Charset encoding)	Reads the contents of a file line by line to a List of Strings.
static void	writeByteArrayToFile(File file, byte[] data)	Writes a byte array to a file creating the file if it does not exist.
static void	writeByteArrayToFile(File file, byte[] data, boolean append)	Writes a byte array to a file creating the file if it does not exist.
static void	writeByteArrayToFile(File file, byte[] data, int off, int len, boolean append)	Writes len bytes from the specified byte array starting at offset off to a file, creating the file if it does not exist.
static void	writeStringToFile(File file, String data)	Deprecated. 2.5 use writeStringToFile(File, String, Charset, boolean) instead
static void	writeStringToFile(File file, String data, String encoding)	Writes a String to a file creating the file if it does not exist.
static void	writeStringToFile(File file, String data, Charset encoding, boolean append)	Writes a String to a file creating the file if it does not exist.

Methods inherited from class java.lang.Object

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

Field Detail

ONE_KB

public static final long ONE_KB

The number of bytes in a kilobyte.

See Also:

Constant Field Values

ONE_MB

public static final long ONE_MB

The number of bytes in a megabyte.

See Also:

Constant Field Values

Method Detail

deleteDirectory

public static void deleteDirectory(File directory)
                            throws IOException

Deletes a directory recursively.

Parameters:

directory - directory to delete

Throws:

IOException - in case deletion is unsuccessful

isSymlink

public static boolean isSymlink(File file)
                         throws IOException

Determines whether the specified file is a Symbolic Link rather than an actual file.

Will not return true if there is a Symbolic Link anywhere in the path, only if the specific file is.

Note: the current implementation always returns false if the system is detected as Windows

For code that runs on Java 1.7 or later, use the following method instead:
boolean java.nio.file.Files.isSymbolicLink(Path path)

Parameters:

file - the file to check

Returns:

true if the file is a Symbolic Link

Throws:

IOException - if an IO error occurs while checking the file

Since:

2.0

cleanDirectory

public static void cleanDirectory(File directory)
                           throws IOException

Deletes a directory recursively.

Parameters:

directory - directory to delete

Throws:

IOException - in case deletion is unsuccessful

forceDelete

public static void forceDelete(File file)
                        throws IOException

Deletes a file. If file is a directory, delete it and all sub-directories.

The difference between File.delete() and this method are:

• A directory to be deleted does not have to be empty.
• You get exceptions when a file or directory cannot be deleted. (java.io.File methods returns a boolean)

Parameters:

file - file or directory to delete, must not be null

Throws:

NullPointerException - if the directory is null

FileNotFoundException - if the file was not found

IOException - in case deletion is unsuccessful

getTempDirectoryPath

public static String getTempDirectoryPath()

Returns the path to the system temporary directory.

Returns:

the path to the system temporary directory.

Since:

2.0

readFileToString

@Deprecated
public static String readFileToString(File file)
                               throws IOException

Deprecated.

2.5 use readFileToString(File, Charset) instead

Reads the contents of a file into a String using the default encoding for the VM. The file is always closed.

Parameters:

file - the file to read, must not be null

Returns:

the file contents, never null

Throws:

IOException - in case of an I/O error

Since:

1.3.1

readFileToString

public static String readFileToString(File file,
                                      Charset encoding)
                               throws IOException

Reads the contents of a file into a String. The file is always closed.

Parameters:

file - the file to read, must not be null

encoding - the encoding to use, null means platform default

Returns:

the file contents, never null

Throws:

IOException - in case of an I/O error

Since:

2.3

readFileToString

public static String readFileToString(File file,
                                      String encoding)
                               throws IOException

Reads the contents of a file into a String. The file is always closed.

Parameters:

file - the file to read, must not be null

encoding - the encoding to use, null means platform default

Returns:

the file contents, never null

Throws:

IOException - in case of an I/O error

Since:

2.3

openInputStream

public static InputStream openInputStream(File file)
                                   throws IOException

Opens a FileInputStream for the specified file, providing better error messages than simply calling new FileInputStream(file).

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

An exception is thrown if the file does not exist. An exception is thrown if the file object exists but is a directory. An exception is thrown if the file exists but cannot be read.

Parameters:

file - the file to open for input, must not be null

Returns:

a new InputStream for the specified file

Throws:

FileNotFoundException - if the file does not exist

IOException - if the file object is a directory

IOException - if the file cannot be read

Since:

1.3

writeStringToFile

@Deprecated
public static void writeStringToFile(File file,
                                     String data)
                              throws IOException

Deprecated.

2.5 use writeStringToFile(File, String, Charset, boolean) instead

Writes a String to a file creating the file if it does not exist using the default encoding for the VM.

Parameters:

file - the file to write

data - the content to write to the file

Throws:

IOException - in case of an I/O error

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     String encoding)
                              throws IOException

Writes a String to a file creating the file if it does not exist. NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:

file - the file to write

data - the content to write to the file

encoding - the encoding to use, null means platform default

Throws:

IOException - in case of an I/O error

UnsupportedEncodingException - if the encoding is not supported by the VM

writeStringToFile

public static void writeStringToFile(File file,
                                     String data,
                                     Charset encoding,
                                     boolean append)
                              throws IOException

Writes a String to a file creating the file if it does not exist.

Parameters:

file - the file to write

data - the content to write to the file

encoding - the encoding to use, null means platform default

append - if true, then the String will be added to the end of the file rather than overwriting

Throws:

IOException - in case of an I/O error

Since:

2.3

openOutputStream

public static OutputStream openOutputStream(File file,
                                            boolean append)
                                     throws IOException

Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

The parent directory will be created if it does not exist. The file will be created if it does not exist. An exception is thrown if the file object exists but is a directory. An exception is thrown if the file exists but cannot be written to. An exception is thrown if the parent directory cannot be created.

Parameters:

file - the file to open for output, must not be null

append - if true, then bytes will be added to the end of the file rather than overwriting

Returns:

a new OutputStream for the specified file

Throws:

IOException - if the file object is a directory

IOException - if the file cannot be written to

IOException - if a parent directory needs creating but that fails

Since:

2.1

getTempDirectory

public static File getTempDirectory()

Returns a File representing the system temporary directory.

Returns:

the system temporary directory.

Since:

2.0

deleteQuietly

public static boolean deleteQuietly(File file)

Deletes a file, never throwing an exception. If file is a directory, delete it and all sub-directories.

The difference between File.delete() and this method are:

• A directory to be deleted does not have to be empty.
• No exceptions are thrown when a file or directory cannot be deleted.

Parameters:

file - file or directory to delete, can be null

Returns:

true if the file or directory was deleted, otherwise false

Since:

1.4

writeByteArrayToFile

public static void writeByteArrayToFile(File file,
                                        byte[] data)
                                 throws IOException

Writes a byte array to a file creating the file if it does not exist.

NOTE: As from v1.3, the parent directories of the file will be created if they do not exist.

Parameters:

file - the file to write to

data - the content to write to the file

Throws:

IOException - in case of an I/O erroe

Since:

1.1

writeByteArrayToFile

public static void writeByteArrayToFile(File file,
                                        byte[] data,
                                        boolean append)
                                 throws IOException

Writes a byte array to a file creating the file if it does not exist.

Parameters:

file - the file to write to

data - the content to write to the file

append - if true, then bytes will be added to the end of the file rather than overwriting

Throws:

IOException - in case of an I/O error

Since:

2.1

writeByteArrayToFile

public static void writeByteArrayToFile(File file,
                                        byte[] data,
                                        int off,
                                        int len,
                                        boolean append)
                                 throws IOException

Writes len bytes from the specified byte array starting at offset off to a file, creating the file if it does not exist.

Parameters:

file - the file to write to

data - the content to write to the file

off - the start offset in the data

len - the number of bytes to write

append - if true, then bytes will be added to the end of the file rather than overwriting

Throws:

IOException - in case of an I/O error

Since:

2.5

readFileToByteArray

public static byte[] readFileToByteArray(File file)
                                  throws IOException

Reads the contents of a file into a byte array. The file is always closed.

Parameters:

file - the file to read, must not be null

Returns:

the file contents, never null

Throws:

IOException - in case of an I/O error

Since:

1.1

openOutputStream

public static OutputStream openOutputStream(File file)
                                     throws IOException

Opens a FileOutputStream for the specified file, checking and creating the parent directory if it does not exist.

At the end of the method either the stream will be successfully opened, or an exception will have been thrown.

The parent directory will be created if it does not exist. The file will be created if it does not exist. An exception is thrown if the file object exists but is a directory. An exception is thrown if the file exists but cannot be written to. An exception is thrown if the parent directory cannot be created.

Parameters:

file - the file to open for output, must not be null

Returns:

a new OutputStream for the specified file

Throws:

IOException - if the file object is a directory

IOException - if the file cannot be written to

IOException - if a parent directory needs creating but that fails

Since:

1.3

readLines

@Deprecated
public static List<String> readLines(File file)
                              throws IOException

Deprecated.

2.5 use readLines(File, Charset) instead

Reads the contents of a file line by line to a List of Strings using the default encoding for the VM. The file is always closed.

Parameters:

file - the file to read, must not be null

Returns:

the list of Strings representing each line in the file, never null

Throws:

IOException - in case of an I/O error

Since:

1.3

readLines

public static List<String> readLines(File file,
                                     Charset encoding)
                              throws IOException

Reads the contents of a file line by line to a List of Strings. The file is always closed.

Parameters:

file - the file to read, must not be null

encoding - the encoding to use, null means platform default

Returns:

the list of Strings representing each line in the file, never null

Throws:

IOException - in case of an I/O error

Since:

2.3