org.apache.derby.impl.io

Class JarDBFile

java.lang.Object

org.apache.derby.impl.io.InputStreamFile

org.apache.derby.impl.io.JarDBFile

All Implemented Interfaces:

StorageFile

 class JarDBFile
extends InputStreamFile

This class provides a jar file based implementation of the StorageFile interface. It is used by the database engine to access persistent data and transaction logs under the jar subsubprotocol.

Field Summary

Fields

Modifier and Type	Field and Description
private JarStorageFactory	storageFactory

Fields inherited from class org.apache.derby.impl.io.InputStreamFile

nameStart, path

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

EXCLUSIVE_FILE_LOCK, EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE, NO_FILE_LOCK_SUPPORT

Constructor Summary

Constructors

Modifier	Constructor and Description
(package private)	JarDBFile(JarDBFile dir, java.lang.String name)
(package private)	JarDBFile(JarStorageFactory storageFactory, java.lang.String path)
private	JarDBFile(JarStorageFactory storageFactory, java.lang.String child, int pathLen)
(package private)	JarDBFile(JarStorageFactory storageFactory, java.lang.String parent, java.lang.String name)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	exists() Tests whether the named file exists.
private java.util.zip.ZipEntry	getEntry()
java.io.InputStream	getInputStream() Creates an input stream from a file name.
(package private) StorageFile	getParentDir(int pathLen) Get the name of the parent directory if this name includes a parent.
java.net.URL	getURL() Return a URL for this file (resource).
long	length() Returns the length of the named file if it is not a directory.
java.lang.String	toString() Get the file name for diagnostic purposes.

Methods inherited from class org.apache.derby.impl.io.InputStreamFile

canWrite, createNewFile, delete, deleteAll, equals, getCanonicalPath, getExclusiveFileLock, getName, getOutputStream, getOutputStream, getParentDir, getPath, getRandomAccessFile, hashCode, isDirectory, limitAccessToOwner, list, mkdir, mkdirs, releaseExclusiveFileLock, renameTo, setReadOnly

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

storageFactory

private final JarStorageFactory storageFactory

Constructor Detail

JarDBFile

JarDBFile(JarStorageFactory storageFactory,
         java.lang.String path)

JarDBFile

JarDBFile(JarStorageFactory storageFactory,
         java.lang.String parent,
         java.lang.String name)

JarDBFile

JarDBFile(JarDBFile dir,
         java.lang.String name)

JarDBFile

private JarDBFile(JarStorageFactory storageFactory,
         java.lang.String child,
         int pathLen)

Method Detail

exists

public boolean exists()

Tests whether the named file exists.

Specified by:

exists in interface StorageFile

Specified by:

exists in class InputStreamFile

Returns:

true if the named file exists, false if not.

getEntry

private java.util.zip.ZipEntry getEntry()

length

public long length()

Returns the length of the named file if it is not a directory. The return value is not specified if the file is a directory.

Specified by:

length in interface StorageFile

Overrides:

length in class InputStreamFile

Returns:

The length, in bytes, of the named file if it exists and is not a directory, 0 if the file does not exist, or any value if the named file is a directory.

getParentDir

StorageFile getParentDir(int pathLen)

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

Specified by:

getParentDir in class InputStreamFile

Parameters:

pathLen - the length of the parent's path name.

Returns:

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

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.io.FileNotFoundException

Creates an input stream from a file name.

Specified by:

getInputStream in interface StorageFile

Specified by:

getInputStream in class InputStreamFile

Returns:

an input stream suitable for reading from the file.

Throws:

java.io.FileNotFoundException - if the file is not found.

toString

public java.lang.String toString()

Get the file name for diagnostic purposes. Usually the same as getPath().

Overrides:

toString in class InputStreamFile

Returns:

the file name

getURL

public java.net.URL getURL()
                    throws java.net.MalformedURLException

Return a URL for this file (resource). Returns a URL according to the spec for java.net.JarURLConnection

Specified by:

getURL in interface StorageFile

Overrides:

getURL in class InputStreamFile

Throws:

java.net.MalformedURLException - File cannot be represented as a URL.

See Also:

StorageFile.getURL()