Package org.apache.derby.impl.io
Class InputStreamFile<F extends BaseStorageFactory>
java.lang.Object
org.apache.derby.impl.io.InputStreamFile<F>
- Type Parameters:
F
- the storage factory class used by the subsubprotocol
- All Implemented Interfaces:
StorageFile
This class provides the base for read-only stream implementations of the StorageFile interface. It is used with the
classpath, jar, http, and https subsubprotocols
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Field Summary
FieldsModifier and TypeFieldDescription(package private) final int
(package private) final String
(package private) final F
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
ConstructorsConstructorDescriptionInputStreamFile
(F storageFactory, String path) InputStreamFile
(F storageFactory, String child, int pathLen) InputStreamFile
(F storageFactory, String parent, String name) InputStreamFile
(InputStreamFile<F> dir, String name) -
Method Summary
Modifier and TypeMethodDescriptionboolean
canWrite()
Determine whether the named file is writable.boolean
If the named file does not already exist then create it as an empty normal file.boolean
delete()
Deletes the named file or empty directory.boolean
Deletes the named file and, if it is a directory, all the files and directories it contains.boolean
abstract boolean
exists()
Tests whether the named file exists.Converts this StorageFile into a canonical pathname string.int
Get an exclusive lock with this name.abstract InputStream
Creates an input stream from a file name.getName()
Creates an output stream from a file name.getOutputStream
(boolean append) Creates an output stream from a file name.Get the name of the parent directory if this name includes a parent.(package private) abstract StorageFile
getParentDir
(int pathLen) Get the parent of this file.getPath()
Converts this StorageFile into a pathname string.getRandomAccessFile
(String mode) Get a random access file.int
hashCode()
boolean
Tests whether the named file is a directory, or not.void
Use when creating a new file.String[]
list()
Get the names of all files and sub-directories in the directory named by this path name.boolean
mkdir()
Creates the named directory.boolean
mkdirs()
Creates the named directory, and all nonexistent parent directories.void
Release the resource associated with an earlier acquired exclusive lockboolean
renameTo
(StorageFile newName) Rename the file denoted by this name.boolean
Make the named file or directory read-only.toString()
Get the file name for diagnostic purposes.
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Field Details
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path
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nameStart
final int nameStart -
storageFactory
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Constructor Details
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InputStreamFile
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InputStreamFile
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InputStreamFile
InputStreamFile(InputStreamFile<F> dir, String name) -
InputStreamFile
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Method Details
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equals
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hashCode
public int hashCode() -
list
Get the names of all files and sub-directories in the directory named by this path name.- Specified by:
list
in interfaceStorageFile
- Returns:
- An array of the names of the files and directories in this directory denoted by this abstract pathname. The returned array will have length 0 if this directory is empty. Returns null if this StorageFile is not a directory, or if an I/O error occurs.
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canWrite
public boolean canWrite()Determine whether the named file is writable.- Specified by:
canWrite
in interfaceStorageFile
- Returns:
- true if the file exists and is writable, false if not.
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exists
public abstract boolean exists()Tests whether the named file exists.- Specified by:
exists
in interfaceStorageFile
- Returns:
- true if the named file exists, false if not.
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isDirectory
public boolean isDirectory()Tests whether the named file is a directory, or not. This is only called in writable storage factories.- Specified by:
isDirectory
in interfaceStorageFile
- Returns:
- true if named file exists and is a directory, false if not. The return value is undefined if the storage is read-only.
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delete
public boolean delete()Deletes the named file or empty directory. This method does not delete non-empty directories.- Specified by:
delete
in interfaceStorageFile
- Returns:
- true if the named file or directory is successfully deleted, 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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getPath
Converts this StorageFile into a pathname string. The character returned by StorageFactory.getSeparator() is used to separate the directory and file names in the sequence.The returned path may include the database directory. Therefore it cannot be directly used to make an StorageFile equivalent to this one.
- Specified by:
getPath
in interfaceStorageFile
- Returns:
- The pathname as a string.
- See Also:
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getCanonicalPath
Description copied from interface:StorageFile
Converts this StorageFile into a canonical pathname string. The form of the canonical path is system dependent.- Specified by:
getCanonicalPath
in interfaceStorageFile
- Returns:
- The pathname as a string.
- Throws:
IOException
- if an I/O error occurred while finding the canonical name
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getName
- Specified by:
getName
in interfaceStorageFile
- Returns:
- The last segment in the path name, "" if the path name sequence is empty.
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createNewFile
If the named file does not already exist then create it as an empty normal file. The implementation must synchronize with other threads accessing the same file (in the same or a different process). If two threads both attempt to create a file with the same name at the same time then at most one should succeed.- Specified by:
createNewFile
in interfaceStorageFile
- Returns:
- true if this thread's invocation of createNewFile successfully created the named file; false if not, i.e. false if the named file already exists or if another concurrent thread created it.
- Throws:
IOException
- - If the directory does not exist or some other I/O error occurred
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renameTo
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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mkdir
public boolean mkdir()Creates the named directory.- Specified by:
mkdir
in interfaceStorageFile
- Returns:
- true if the directory was created; false if not.
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mkdirs
public boolean mkdirs()Creates the named directory, and all nonexistent parent directories.- Specified by:
mkdirs
in interfaceStorageFile
- Returns:
- true if the directory was created, false if not
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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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getParentDir
Get the parent of this file.- Parameters:
pathLen
- the length of the parent's path name.
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setReadOnly
public boolean setReadOnly()Make the named file or directory read-only. This interface does not specify whether this also makes the file undeletable.- Specified by:
setReadOnly
in interfaceStorageFile
- Returns:
- true if the named file or directory was made read-only, or it already was read-only; false if not.
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getOutputStream
Creates an output stream from a file name. If a normal file already exists with this name it will first be truncated to zero length.- Specified by:
getOutputStream
in interfaceStorageFile
- Returns:
- an output stream suitable for writing to the file.
- Throws:
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
Creates an output stream from a file name. If a normal file already exists with this name it will first be truncated to zero length.- 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:
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
Creates an input stream from a file name.- Specified by:
getInputStream
in interfaceStorageFile
- Returns:
- an input stream suitable for reading from the file.
- Throws:
FileNotFoundException
- if the file is not found.
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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.- 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:
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getRandomAccessFile
Get a random access 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. However, 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:
IllegalArgumentException
- if the mode argument is not equal to one of "r", "rw", "rws", or "rwd".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:
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toString
Get the file name for diagnostic purposes. Usually the same as getPath(). -
limitAccessToOwner
public void limitAccessToOwner()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
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