Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.io.vfmem.VirtualFile

Modifier and Type	Field and Description
private final DataStore	dStore The data store this virtual file belongs to.
private final String	path The path of this virtual file.

Access	Constructor and Description
public	VirtualFile(String the path of this virtual file path, DataStore the store this handle belongs to dbData) Creates a new virtual file handle.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: `true` if this file exists and can be written to, `false` otherwise. canWrite() Implements org.apache.derby.io.StorageFile.canWrite. Tells if this file can be written to.
public boolean	Returns: `true` if the file was successfully created, `false` otherwise createNewFile() Implements org.apache.derby.io.StorageFile.createNewFile. Creates the the file denoted by this virtual file object.
public boolean	Returns: `true` if this file exists and is successfully deleted, `false` otherwise. delete() Implements org.apache.derby.io.StorageFile.delete. Deletes this file, of if exists.
public boolean	Returns: `true` if this file and all contents are successfully deleted, `false` otherwise. deleteAll() Implements org.apache.derby.io.StorageFile.deleteAll. Deletes the path denoted by this file and all its contents, including sub directories.
public boolean	Returns: `true` if this file exists, `false` otherwise. exists() Implements org.apache.derby.io.StorageFile.exists. Tells if this file exists.
public String	getCanonicalPath() Implements org.apache.derby.io.StorageFile.getCanonicalPath. Converts this StorageFile into a canonical pathname string.
private DataStoreEntry	Returns: The assoiciated `DataStoreEntry` if it exists, `null` if it doesn't exist. getEntry() Returns the data store entry denoted by this file, if it exists.
public int	getExclusiveFileLock() Implements org.apache.derby.io.StorageFile.getExclusiveFileLock. Get an exclusive lock with this name.
public InputStream	Returns: An `InputStream` instance. getInputStream() Implements org.apache.derby.io.StorageFile.getInputStream. Returns an input stream for the file denoted.
public String	getName() Implements org.apache.derby.io.StorageFile.getName.
public OutputStream	Returns: An `OutputStream`-instance. getOutputStream() Implements org.apache.derby.io.StorageFile.getOutputStream. Obtains an output stream for the file denoted.
public OutputStream	Returns: An `OutputStream`-instance. getOutputStream(boolean tells if the file should be appended or truncated append) Implements org.apache.derby.io.StorageFile.getOutputStream. Obtains an output stream for the file denoted.
public StorageFile	getParentDir() Implements org.apache.derby.io.StorageFile.getParentDir. Get the name of the parent directory if this name includes a parent.
public String	Returns: The path of this file. getPath() Implements org.apache.derby.io.StorageFile.getPath. Returns the path of this file.
public StorageRandomAccessFile	Returns: A `StorageRandomAccessFile`-instance. getRandomAccessFile(String file mode, one of "r", "rw", "rws" or "rwd" (lower-case letters are required) mode) Implements org.apache.derby.io.StorageFile.getRandomAccessFile. Creates a random access file that can be used to read and write from/into the file.
public boolean	Returns: `true` if this file represents an existing directoy, `false` otherwise. isDirectory() Implements org.apache.derby.io.StorageFile.isDirectory. Tells if this file is a directory.
public long	Returns: The length of the existing file, or `0` if the path denotes a directory or a non-existing file. length() Returns the length of the file.
public void	limitAccessToOwner() Implements org.apache.derby.io.StorageFile.limitAccessToOwner. Use when creating a new file.
public String[]	Returns: A list of all files and directories, or `null` if this file doesn't denote a directory or doesn't exist. list() Implements org.apache.derby.io.StorageFile.list. Returns the contents of the directory denoted by this file, including any sub directories and their contents.
public boolean	Returns: `true` if the directory was created, `false` otherwise. mkdir() Implements org.apache.derby.io.StorageFile.mkdir. Creates the directory denoted by this virtual file if it doesn't exist.
public boolean	Returns: `true` if the directory was created, `false` otherwise. mkdirs() Implements org.apache.derby.io.StorageFile.mkdirs. Creates the directory and any parent directories denoted by this virtual file.
public void	releaseExclusiveFileLock() Implements org.apache.derby.io.StorageFile.releaseExclusiveFileLock. Release the resource associated with an earlier acquired exclusive lock releaseExclusiveFileLock() may delete the file
public boolean	Returns: `true` if the fail was renamed, `false` otherwise renameTo(StorageFile the new name newName) Implements org.apache.derby.io.StorageFile.renameTo. Renames the file denoted by this handle.
public boolean	setReadOnly() Implements org.apache.derby.io.StorageFile.setReadOnly. Make the named file or directory read-only.
public String	Returns: Textual representation. toString() Overrides java.lang.Object.toString. Returns a textual representation of this file.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

dStore	back to summary
private final DataStore dStore The data store this virtual file belongs to.

path	back to summary
private final String path The path of this virtual file.

VirtualFile	back to summary
public VirtualFile(String path, DataStore dbData) Creates a new virtual file handle. Parameters path:String the path of this virtual file dbData:DataStore the store this handle belongs to

Method Detail

canWrite back to summary

canWrite	back to summary
public boolean canWrite() Implements org.apache.derby.io.StorageFile.canWrite. Tells if this file can be written to. Returns:boolean `true` if this file exists and can be written to, `false` otherwise.

public boolean canWrite()

Implements org.apache.derby.io.StorageFile.canWrite.

Tells if this file can be written to.

Returns:boolean: true if this file exists and can be written to, false otherwise.

createNewFile back to summary

createNewFile	back to summary
public boolean createNewFile() Implements org.apache.derby.io.StorageFile.createNewFile. Creates the the file denoted by this virtual file object. Returns:boolean `true` if the file was successfully created, `false` otherwise

public boolean createNewFile()

Implements org.apache.derby.io.StorageFile.createNewFile.

Creates the the file denoted by this virtual file object.

Returns:boolean: true if the file was successfully created, false otherwise

delete back to summary

delete	back to summary
public boolean delete() Implements org.apache.derby.io.StorageFile.delete. Deletes this file, of if exists. Returns:boolean `true` if this file exists and is successfully deleted, `false` otherwise.

public boolean delete()

Implements org.apache.derby.io.StorageFile.delete.

Deletes this file, of if exists.

Returns:boolean: true if this file exists and is successfully deleted, false otherwise.

deleteAll back to summary

deleteAll	back to summary
public boolean deleteAll() Implements org.apache.derby.io.StorageFile.deleteAll. Deletes the path denoted by this file and all its contents, including sub directories. Returns:boolean `true` if this file and all contents are successfully deleted, `false` otherwise.

public boolean deleteAll()

Implements org.apache.derby.io.StorageFile.deleteAll.

Deletes the path denoted by this file and all its contents, including sub directories.

Returns:boolean: true if this file and all contents are successfully deleted, false otherwise.

exists back to summary

exists	back to summary
public boolean exists() Implements org.apache.derby.io.StorageFile.exists. Tells if this file exists. Returns:boolean `true` if this file exists, `false` otherwise.

public boolean exists()

Implements org.apache.derby.io.StorageFile.exists.

Tells if this file exists.

Returns:boolean: true if this file exists, false otherwise.

getCanonicalPath	back to summary
public String getCanonicalPath() Implements org.apache.derby.io.StorageFile.getCanonicalPath. Doc from org.apache.derby.io.StorageFile.getCanonicalPath. Converts this StorageFile into a canonical pathname string. The form of the canonical path is system dependent. Returns:String The pathname as a string.

getCanonicalPath

back to summary

public String getCanonicalPath()

Implements org.apache.derby.io.StorageFile.getCanonicalPath.

Doc from org.apache.derby.io.StorageFile.getCanonicalPath.

Converts this StorageFile into a canonical pathname string. The form of the canonical path is system dependent.

Returns:String: The pathname as a string.

getEntry back to summary

getEntry	back to summary
private DataStoreEntry getEntry() Returns the data store entry denoted by this file, if it exists. Returns:DataStoreEntry The assoiciated `DataStoreEntry` if it exists, `null` if it doesn't exist.

private DataStoreEntry getEntry()

Returns the data store entry denoted by this file, if it exists.

Returns:DataStoreEntry: The assoiciated DataStoreEntry if it exists, null if it doesn't exist.

getExclusiveFileLock	back to summary
public int getExclusiveFileLock() throws StandardException Implements org.apache.derby.io.StorageFile.getExclusiveFileLock. Doc from org.apache.derby.io.StorageFile.getExclusiveFileLock. Get an exclusive lock with this name. This is used to ensure that two or more JVMs do not open the same database at the same time. ny StorageFile that has getExclusiveFileLock() called on it is not intended to be read from or written to. It's sole purpose is to provide a locked entity to avoid multiple instances of Derby accessing the same database. getExclusiveFileLock() may delete or overwrite any existing file. Returns:int EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE if the lock cannot be acquired because it is already held. EXCLUSIVE_FILE_LOCK if the lock was successfully acquired. NO_FILE_LOCK_SUPPORT if the system does not support exclusive locks.

getExclusiveFileLock

back to summary

public int getExclusiveFileLock() throws StandardException

Implements org.apache.derby.io.StorageFile.getExclusiveFileLock.

Doc from org.apache.derby.io.StorageFile.getExclusiveFileLock.

Get an exclusive lock with this name. This is used to ensure that two or more JVMs do not open the same database at the same time. ny StorageFile that has getExclusiveFileLock() called on it is not intended to be read from or written to. It's sole purpose is to provide a locked entity to avoid multiple instances of Derby accessing the same database. getExclusiveFileLock() may delete or overwrite any existing file.

Returns:int: EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE if the lock cannot be acquired because it is already held.
EXCLUSIVE_FILE_LOCK if the lock was successfully acquired.
NO_FILE_LOCK_SUPPORT if the system does not support exclusive locks.

getInputStream back to summary

getInputStream	back to summary
public InputStream getInputStream() throws FileNotFoundException Implements org.apache.derby.io.StorageFile.getInputStream. Returns an input stream for the file denoted. Returns:InputStream An `InputStream` instance. Exceptions FileNotFoundException: if the file doesn't exists or it is a directory

public InputStream getInputStream() throws FileNotFoundException

Implements org.apache.derby.io.StorageFile.getInputStream.

Returns an input stream for the file denoted.

Returns:InputStream

An InputStream instance.

Exceptions

FileNotFoundException:: if the file doesn't exists or it is a directory

getName	back to summary
public String getName() Implements org.apache.derby.io.StorageFile.getName. Returns:String Doc from org.apache.derby.io.StorageFile.getName. The last segment in the path name, "" if the path name sequence is empty.

getName

back to summary

public String getName()

Implements org.apache.derby.io.StorageFile.getName.

Returns:String

Doc from org.apache.derby.io.StorageFile.getName.

The last segment in the path name, "" if the path name sequence is empty.

getOutputStream back to summary

getOutputStream	back to summary
public OutputStream getOutputStream() throws FileNotFoundException Implements org.apache.derby.io.StorageFile.getOutputStream. Obtains an output stream for the file denoted. If the file already exists, it will be truncated. Returns:OutputStream An `OutputStream`-instance. Exceptions FileNotFoundException: if the denoted path is a directory, the file is read-only, the file cannot be created or any other reason why an `OutputStream` cannot be created for the file

public OutputStream getOutputStream() throws FileNotFoundException

Implements org.apache.derby.io.StorageFile.getOutputStream.

Obtains an output stream for the file denoted.

If the file already exists, it will be truncated.

Returns:OutputStream

An OutputStream-instance.

Exceptions

FileNotFoundException:: if the denoted path is a directory, the file is read-only, the file cannot be created or any other reason why an OutputStream cannot be created for the file

getOutputStream back to summary

getOutputStream	back to summary
public OutputStream getOutputStream(boolean append) throws FileNotFoundException Implements org.apache.derby.io.StorageFile.getOutputStream. Obtains an output stream for the file denoted. Parameters append:boolean tells if the file should be appended or truncated Returns:OutputStream An `OutputStream`-instance. Exceptions FileNotFoundException: if the denoted path is a directory, the file is read-only, the file cannot be created or any other reason why an `OutputStream` cannot be created for the file

public OutputStream getOutputStream(boolean append) throws FileNotFoundException

Implements org.apache.derby.io.StorageFile.getOutputStream.

Obtains an output stream for the file denoted.

Parameters

append:boolean: tells if the file should be appended or truncated

Returns:OutputStream

An OutputStream-instance.

Exceptions

FileNotFoundException:: if the denoted path is a directory, the file is read-only, the file cannot be created or any other reason why an OutputStream cannot be created for the file

getParentDir	back to summary
public StorageFile getParentDir() Implements org.apache.derby.io.StorageFile.getParentDir. Doc from org.apache.derby.io.StorageFile.getParentDir. Get the name of the parent directory if this name includes a parent. Returns:StorageFile An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if it does not have a parent.

getParentDir

back to summary

public StorageFile getParentDir()

Implements org.apache.derby.io.StorageFile.getParentDir.

Doc from org.apache.derby.io.StorageFile.getParentDir.

Get the name of the parent directory if this name includes a parent.

Returns:StorageFile: An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if it does not have a parent.

getPath	back to summary
public String getPath() Implements org.apache.derby.io.StorageFile.getPath. Returns the path of this file. Returns:String The path of this file.

getPath

back to summary

public String getPath()

Implements org.apache.derby.io.StorageFile.getPath.

Returns the path of this file.

Returns:String: The path of this file.

getRandomAccessFile back to summary

getRandomAccessFile	back to summary
public StorageRandomAccessFile getRandomAccessFile(String mode) throws FileNotFoundException Implements org.apache.derby.io.StorageFile.getRandomAccessFile. Creates a random access file that can be used to read and write from/into the file. Parameters mode:String file mode, one of "r", "rw", "rws" or "rwd" (lower-case letters are required) Returns:StorageRandomAccessFile A `StorageRandomAccessFile`-instance. Exceptions FileNotFoundException: if the file denoted is a directory, IllegalArgumentException: if the specificed mode is invalid

public StorageRandomAccessFile getRandomAccessFile(String mode) throws FileNotFoundException

Implements org.apache.derby.io.StorageFile.getRandomAccessFile.

Creates a random access file that can be used to read and write from/into the file.

Parameters

mode:String: file mode, one of "r", "rw", "rws" or "rwd" (lower-case letters are required)

Returns:StorageRandomAccessFile

A StorageRandomAccessFile-instance.

Exceptions

FileNotFoundException:: if the file denoted is a directory,
IllegalArgumentException:: if the specificed mode is invalid

isDirectory back to summary

isDirectory	back to summary
public boolean isDirectory() Implements org.apache.derby.io.StorageFile.isDirectory. Tells if this file is a directory. Note that `false` is returned if this path doesn't exist. Returns:boolean `true` if this file represents an existing directoy, `false` otherwise.

public boolean isDirectory()

Implements org.apache.derby.io.StorageFile.isDirectory.

Tells if this file is a directory.

Note that false is returned if this path doesn't exist.

Returns:boolean: true if this file represents an existing directoy, false otherwise.

length back to summary

length	back to summary
public long length() Returns the length of the file. If the file doesn't exists, or is a directory, `0` is returned. Returns:long The length of the existing file, or `0` if the path denotes a directory or a non-existing file.

public long length()

Returns the length of the file.

If the file doesn't exists, or is a directory, 0 is returned.

Returns:long: The length of the existing file, or 0 if the path denotes a directory or a non-existing file.

limitAccessToOwner back to summary

limitAccessToOwner	back to summary
public void limitAccessToOwner() Implements org.apache.derby.io.StorageFile.limitAccessToOwner. Doc from org.apache.derby.io.StorageFile.limitAccessToOwner. Use when creating a new file. By default, a file created in an underlying file system, if applicable, will have read and write access for the file owner unless the property `derby.useDefaultFilePermissions` is set to `true`.

public void limitAccessToOwner()

Implements org.apache.derby.io.StorageFile.limitAccessToOwner.

Doc from org.apache.derby.io.StorageFile.limitAccessToOwner.

Use when creating a new file. By default, a file created in an underlying file system, if applicable, will have read and write access for the file owner unless the property derby.useDefaultFilePermissions is set to true.

list back to summary

list	back to summary
public String[] list() Implements org.apache.derby.io.StorageFile.list. Returns the contents of the directory denoted by this file, including any sub directories and their contents. Returns:String[] A list of all files and directories, or `null` if this file doesn't denote a directory or doesn't exist.

public String[] list()

Implements org.apache.derby.io.StorageFile.list.

Returns the contents of the directory denoted by this file, including any sub directories and their contents.

Returns:String[]: A list of all files and directories, or null if this file doesn't denote a directory or doesn't exist.

mkdir back to summary

mkdir	back to summary
public boolean mkdir() Implements org.apache.derby.io.StorageFile.mkdir. Creates the directory denoted by this virtual file if it doesn't exist. For the directory to be created, it cannot exist already (either as a file or a directory), and any parent directories must exist. Returns:boolean `true` if the directory was created, `false` otherwise.

public boolean mkdir()

Implements org.apache.derby.io.StorageFile.mkdir.

Creates the directory denoted by this virtual file if it doesn't exist.

For the directory to be created, it cannot exist already (either as a file or a directory), and any parent directories must exist.

Returns:boolean: true if the directory was created, false otherwise.

mkdirs back to summary

mkdirs	back to summary
public boolean mkdirs() Implements org.apache.derby.io.StorageFile.mkdirs. Creates the directory and any parent directories denoted by this virtual file. For the directory to be created, it cannot exist already (either as a file or a directory), and all the parent elements most denote either existing directories or non-existing paths. Returns:boolean `true` if the directory was created, `false` otherwise.

public boolean mkdirs()

Implements org.apache.derby.io.StorageFile.mkdirs.

Creates the directory and any parent directories denoted by this virtual file.

For the directory to be created, it cannot exist already (either as a file or a directory), and all the parent elements most denote either existing directories or non-existing paths.

Returns:boolean: true if the directory was created, false otherwise.

releaseExclusiveFileLock	back to summary
public void releaseExclusiveFileLock() Implements org.apache.derby.io.StorageFile.releaseExclusiveFileLock. Doc from org.apache.derby.io.StorageFile.releaseExclusiveFileLock. Release the resource associated with an earlier acquired exclusive lock releaseExclusiveFileLock() may delete the file

releaseExclusiveFileLock

back to summary

public void releaseExclusiveFileLock()

Implements org.apache.derby.io.StorageFile.releaseExclusiveFileLock.

Doc from org.apache.derby.io.StorageFile.releaseExclusiveFileLock.

Release the resource associated with an earlier acquired exclusive lock releaseExclusiveFileLock() may delete the file

renameTo back to summary

renameTo	back to summary
public boolean renameTo(StorageFile newName) Implements org.apache.derby.io.StorageFile.renameTo. Renames the file denoted by this handle. Parameters newName:StorageFile the new name Returns:boolean `true` if the fail was renamed, `false` otherwise

public boolean renameTo(StorageFile newName)

Implements org.apache.derby.io.StorageFile.renameTo.

Renames the file denoted by this handle.

Parameters

newName:StorageFile: the new name

Returns:boolean

true if the fail was renamed, false otherwise

setReadOnly	back to summary
public boolean setReadOnly() Implements org.apache.derby.io.StorageFile.setReadOnly. Doc from org.apache.derby.io.StorageFile.setReadOnly. Make the named file or directory read-only. This interface does not specify whether this also makes the file undeletable. Returns:boolean true if the named file or directory was made read-only, or it already was read-only; false if not.

setReadOnly

back to summary

public boolean setReadOnly()

Implements org.apache.derby.io.StorageFile.setReadOnly.

Doc from org.apache.derby.io.StorageFile.setReadOnly.

Make the named file or directory read-only. This interface does not specify whether this also makes the file undeletable.

Returns:boolean: true if the named file or directory was made read-only, or it already was read-only; false if not.

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a textual representation of this file. Returns:String Textual representation.

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Returns a textual representation of this file.

Returns:String: Textual representation.

public Class VirtualFile

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail