Package org.apache.derby.impl.io
Class DirFile
- java.lang.Object
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- java.io.File
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- org.apache.derby.impl.io.DirFile
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- 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.
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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
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Fields inherited from interface org.apache.derby.io.StorageFile
EXCLUSIVE_FILE_LOCK, EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE, NO_FILE_LOCK_SUPPORT
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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.
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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 lockboolean
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
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.derby.io.StorageFile
canWrite, createNewFile, delete, exists, getCanonicalPath, getName, getPath, isDirectory, list, mkdir, mkdirs, setReadOnly
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Constructor Detail
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DirFile
DirFile(java.lang.String path)
Construct a DirFile from a path name.- Parameters:
path
- The path name.
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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.
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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.
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Method Detail
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getParentDir
public StorageFile getParentDir()
Get the name of the parent directory if this name includes a parent.- Specified by:
getParentDir
in interfaceStorageFile
- Returns:
- An StorageFile denoting the parent directory of this StorageFile, if it has a parent, null if it does not have a parent.
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getOutputStream
public java.io.OutputStream getOutputStream() throws java.io.FileNotFoundException
Creates an output stream from a file name.- Specified by:
getOutputStream
in interfaceStorageFile
- 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.
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getOutputStream
public java.io.OutputStream getOutputStream(boolean append) throws java.io.FileNotFoundException
Creates an output stream from a file name.- Specified by:
getOutputStream
in interfaceStorageFile
- 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.
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getInputStream
public java.io.InputStream getInputStream() throws java.io.FileNotFoundException
Creates an input stream from a file name.- Specified by:
getInputStream
in interfaceStorageFile
- Returns:
- an input stream suitable for reading from the file.
- Throws:
java.io.FileNotFoundException
- if the file is not found.
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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 interfaceStorageFile
- 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
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releaseExclusiveFileLock
public void releaseExclusiveFileLock()
Release the resource associated with an earlier acquired exclusive lock- Specified by:
releaseExclusiveFileLock
in interfaceStorageFile
- See Also:
getExclusiveFileLock()
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getRandomAccessFile
public StorageRandomAccessFile getRandomAccessFile(java.lang.String mode) throws java.io.FileNotFoundException
Get a random access (read/write) file.- Specified by:
getRandomAccessFile
in interfaceStorageFile
- 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
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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 interfaceStorageFile
- Parameters:
newName
- the new name.- Returns:
- true if the rename succeeded, false if not.
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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 interfaceStorageFile
- Returns:
- true if the named file or directory is successfully deleted, false if not
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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 propertyderby.useDefaultFilePermissions
is set totrue
.- Specified by:
limitAccessToOwner
in interfaceStorageFile
- Throws:
java.io.IOException
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