DirFile (Apache Derby V10.14 Internals)

java.lang.Object
- java.io.File
- - org.apache.derby.impl.io.DirFile

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<java.io.File>, StorageFile
```
class DirFile
extends java.io.File
implements StorageFile
```
This class provides a disk based implementation of the StorageFile interface. It is used by the database engine to access persistent data and transaction logs under the directory (default) subsubprotocol.

Field Summary

Fields
Modifier and Type	Field	Description
`private java.nio.channels.FileLock`	`dbLock`
`private java.nio.channels.FileChannel`	`lockFileChannel`
`private java.io.RandomAccessFile`	`lockFileOpen`

Fields inherited from class java.io.File
pathSeparator, pathSeparatorChar, separator, separatorChar

Fields inherited from interface org.apache.derby.io.StorageFile
EXCLUSIVE_FILE_LOCK, EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE, NO_FILE_LOCK_SUPPORT

Constructor Summary

Constructors
Constructor	Description
`DirFile(java.lang.String path)`	Construct a DirFile from a path name.
`DirFile(java.lang.String directoryName, java.lang.String fileName)`	Construct a DirFile from a directory name and a file name.
`DirFile(DirFile directoryName, java.lang.String fileName)`	Construct a DirFile from a directory name and a file name.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`deleteAll()`	Deletes the named file and, if it is a directory, all the files and directories it contains.
`int`	`getExclusiveFileLock()`	Get an exclusive lock.
`java.io.InputStream`	`getInputStream()`	Creates an input stream from a file name.
`java.io.OutputStream`	`getOutputStream()`	Creates an output stream from a file name.
`java.io.OutputStream`	`getOutputStream(boolean append)`	Creates an output stream from a file name.
`StorageFile`	`getParentDir()`	Get the name of the parent directory if this name includes a parent.
`StorageRandomAccessFile`	`getRandomAccessFile(java.lang.String mode)`	Get a random access (read/write) file.
`void`	`limitAccessToOwner()`	Use when creating a new file.
`void`	`releaseExclusiveFileLock()`	Release the resource associated with an earlier acquired exclusive lock
`boolean`	`renameTo(StorageFile newName)`	Rename the file denoted by this name.

Methods inherited from class java.io.File
canExecute, canRead, canWrite, compareTo, createNewFile, createTempFile, createTempFile, delete, deleteOnExit, equals, exists, getAbsoluteFile, getAbsolutePath, getCanonicalFile, getCanonicalPath, getFreeSpace, getName, getParent, getParentFile, getPath, getTotalSpace, getUsableSpace, hashCode, isAbsolute, isDirectory, isFile, isHidden, lastModified, length, list, list, listFiles, listFiles, listFiles, listRoots, mkdir, mkdirs, renameTo, setExecutable, setExecutable, setLastModified, setReadable, setReadable, setReadOnly, setWritable, setWritable, toPath, toString, toURI, toURL

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.derby.io.StorageFile
canWrite, createNewFile, delete, exists, getCanonicalPath, getName, getPath, isDirectory, list, mkdir, mkdirs, setReadOnly

- Field Detail
  - lockFileOpen
```
private java.io.RandomAccessFile lockFileOpen
```
  - lockFileChannel
```
private java.nio.channels.FileChannel lockFileChannel
```
  - dbLock
```
private java.nio.channels.FileLock dbLock
```
- Constructor Detail
  - DirFile
```
DirFile(java.lang.String path)
```
    Construct a DirFile from a path name.
    
    Parameters:
    
    path - The path name.
  - DirFile
```
DirFile(java.lang.String directoryName,
        java.lang.String fileName)
```
    Construct a DirFile from a directory name and a file name.
    
    Parameters:
    
    directoryName - The directory part of the path name.
    
    fileName - The name of the file within the directory.
  - DirFile
```
DirFile(DirFile directoryName,
        java.lang.String fileName)
```
    Construct a DirFile from a directory name and a file name.
    
    Parameters:
    
    directoryName - The directory part of the path name.
    
    fileName - The name of the file within the directory.
- Method Detail
  - getParentDir
```
public StorageFile getParentDir()
```
    Get the name of the parent directory if this name includes a parent.
    
    Specified by:
    
    getParentDir in interface StorageFile
    
    Returns:
    
    An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if it does not have a parent.
  - getOutputStream
```
public java.io.OutputStream getOutputStream()
                                     throws java.io.FileNotFoundException
```
    Creates an output stream from a file name.
    
    Specified by:
    
    getOutputStream in interface StorageFile
    
    Returns:
    
    an output stream suitable for writing to the file.
    
    Throws:
    
    java.io.FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.
  - getOutputStream
```
public java.io.OutputStream getOutputStream(boolean append)
                                     throws java.io.FileNotFoundException
```
    Creates an output stream from a file name.
    
    Specified by:
    
    getOutputStream in interface StorageFile
    
    Parameters:
    
    append - If true then data will be appended to the end of the file, if it already exists. If false and a normal file already exists with this name the file will first be truncated to zero length.
    
    Returns:
    
    an output stream suitable for writing to the file.
    
    Throws:
    
    java.io.FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.
  - getInputStream
```
public java.io.InputStream getInputStream()
                                   throws java.io.FileNotFoundException
```
    Creates an input stream from a file name.
    
    Specified by:
    
    getInputStream in interface StorageFile
    
    Returns:
    
    an input stream suitable for reading from the file.
    
    Throws:
    
    java.io.FileNotFoundException - if the file is not found.
  - getExclusiveFileLock
```
public int getExclusiveFileLock()
                         throws StandardException
```
    Get an exclusive lock. This is used to ensure that two or more JVMs do not open the same database at the same time.
    
    Specified by:
    
    getExclusiveFileLock in interface StorageFile
    
    Returns:
    
    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.
    
    Throws:
    
    StandardException
  - releaseExclusiveFileLock
```
public void releaseExclusiveFileLock()
```
    Release the resource associated with an earlier acquired exclusive lock
    
    Specified by:
    
    releaseExclusiveFileLock in interface StorageFile
    
    See Also:
    
    getExclusiveFileLock()
  - getRandomAccessFile
```
public StorageRandomAccessFile getRandomAccessFile(java.lang.String mode)
                                            throws java.io.FileNotFoundException
```
    Get a random access (read/write) file.
    
    Specified by:
    
    getRandomAccessFile in interface StorageFile
    
    Parameters:
    
    mode - "r", "rw", "rws", or "rwd". The "rws" and "rwd" modes specify that the data is to be written to persistent store, consistent with the java.io.RandomAccessFile class ("synchronized" with the persistent storage, in the file system meaning of the word "synchronized"). However the implementation is not required to implement the "rws" or "rwd" modes. The implementation may treat "rws" and "rwd" as "rw". It is up to the user of this interface to call the StorageRandomAccessFile.sync method. If the "rws" or "rwd" modes are supported and the RandomAccessFile was opened in "rws" or "rwd" mode then the implementation of StorageRandomAccessFile.sync need not do anything.
    
    Returns:
    
    an object that can be used for random access to the file.
    
    Throws:
    
    java.lang.IllegalArgumentException - if the mode argument is not equal to one of "r", "rw".
    
    java.io.FileNotFoundException - if the file exists but is a directory rather than a regular file, or cannot be opened or created for any other reason .
    
    See Also:
    
    java.io.RandomAccessFile
  - renameTo
```
public boolean renameTo(StorageFile newName)
```
    Rename the file denoted by this name. Note that StorageFile objects are immutable. This method renames the underlying file, it does not change this StorageFile object. The StorageFile object denotes the same name as before, however the exists() method will return false after the renameTo method executes successfully.
    It is not specified whether this method will succeed if a file already exists under the new name.
    
    Specified by:
    
    renameTo in interface StorageFile
    
    Parameters:
    
    newName - the new name.
    
    Returns:
    
    true if the rename succeeded, false if not.
  - deleteAll
```
public boolean deleteAll()
```
    Deletes the named file and, if it is a directory, all the files and directories it contains.
    
    Specified by:
    
    deleteAll in interface StorageFile
    
    Returns:
    
    true if the named file or directory is successfully deleted, false if not
  - limitAccessToOwner
```
public void limitAccessToOwner()
                        throws java.io.IOException
```
    Description copied from interface: StorageFile
    
    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.
    
    Specified by:
    
    limitAccessToOwner in interface StorageFile
    
    Throws:
    
    java.io.IOException

Class DirFile

Field Summary

Fields inherited from class java.io.File

Fields inherited from interface org.apache.derby.io.StorageFile

Constructor Summary

Method Summary

Methods inherited from class java.io.File

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.derby.io.StorageFile

Field Detail

lockFileOpen

lockFileChannel

dbLock

Constructor Detail

DirFile

DirFile

DirFile

Method Detail

getParentDir

getOutputStream

getOutputStream

getInputStream

getExclusiveFileLock

releaseExclusiveFileLock

getRandomAccessFile

renameTo

deleteAll

limitAccessToOwner