Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> [ io overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.apache.derby.impl.io
Class URLFile  

java.lang.Object
  org.apache.derby.impl.io.InputStreamFile
      org.apache.derby.impl.io.URLFile

All Implemented Interfaces:

org.apache.derby.io.StorageFile

---

class URLFile

extends InputStreamFile

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

---

Field Summary
(package private)  int	nameStart
(package private)  java.lang.String	path
private  URLStorageFactory	storageFactory

 

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

EXCLUSIVE_FILE_LOCK, EXCLUSIVE_FILE_LOCK_NOT_AVAILABLE, NO_FILE_LOCK_SUPPORT

 

Constructor Summary
(package private)	URLFile(URLFile dir, java.lang.String name)
(package private)	URLFile(URLStorageFactory storageFactory, java.lang.String path)
private	URLFile(URLStorageFactory storageFactory, java.lang.String child, int pathLen)
(package private)	URLFile(URLStorageFactory storageFactory, java.lang.String parent, java.lang.String name)

 

Method Summary
boolean	canWrite()           Determine whether the named file is writable.
boolean	createNewFile()           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	deleteAll()           Deletes the named file and, if it is a directory, all the files and directories it contains.
boolean	equals(java.lang.Object other)           Determine whether this Object is semantically equal to another Object.
boolean	exists()           Tests whether the named file exists.
java.lang.String	getCanonicalPath()           Converts this StorageFile into a canonical pathname string.
int	getExclusiveFileLock()           Get an exclusive lock with this name.
java.io.InputStream	getInputStream()           Creates an input stream from a file name.
java.lang.String	getName()
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.
org.apache.derby.io.StorageFile	getParentDir()           Get the name of the parent directory if this name includes a parent.
(package private)  org.apache.derby.io.StorageFile	getParentDir(int pathLen)           Get the parent of this file.
java.lang.String	getPath()           Converts this StorageFile into a pathname string.
org.apache.derby.io.StorageRandomAccessFile	getRandomAccessFile(java.lang.String mode)           Get a random access file.
int	hashCode()           Get a value that represents this Object, as uniquely as possible within the confines of an int.
boolean	isDirectory()           Tests whether the named file is a directory, or not.
long	length()           Returns the length of the named file if it is not a directory.
java.lang.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	releaseExclusiveFileLock()           Release the resource associated with an earlier acquired exclusive lock
boolean	renameTo(org.apache.derby.io.StorageFile newName)           Rename the file denoted by this name.
boolean	setReadOnly()           Make the named file or directory read-only.
java.lang.String	toString()           Get the file name for diagnostic purposes.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

storageFactory

private final URLStorageFactory storageFactory

---

path

final java.lang.String path

---

nameStart

final int nameStart

Constructor Detail

URLFile

URLFile(URLStorageFactory storageFactory,
        java.lang.String path)

---

URLFile

URLFile(URLStorageFactory storageFactory,
        java.lang.String parent,
        java.lang.String name)

---

URLFile

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

---

URLFile

private URLFile(URLStorageFactory storageFactory,
                java.lang.String child,
                int pathLen)

Method Detail

exists

public boolean exists()

Tests whether the named file exists.

Specified by:

exists in interface org.apache.derby.io.StorageFile

Specified by:

exists in class InputStreamFile

---

getParentDir

org.apache.derby.io.StorageFile getParentDir(int pathLen)

Get the parent of this file.

Specified by:

getParentDir in class InputStreamFile

---

getInputStream

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

Creates an input stream from a file name.

Specified by:

getInputStream in interface org.apache.derby.io.StorageFile

Specified by:

getInputStream in class InputStreamFile

---

equals

public boolean equals(java.lang.Object other)

Description copied from class: java.lang.Object

Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

• It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
• It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
• It must be reflexive. a.equals(a) must always be true.
• It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
• a.equals(null) must be false.
• It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a java.lang.ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a java.lang.NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, java.util.IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

---

hashCode

public int hashCode()

Description copied from class: java.lang.Object

Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

• Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
• It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in java.util.Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

---

list

public java.lang.String[] list()

Get the names of all files and sub-directories in the directory named by this path name.

Specified by:

list in interface org.apache.derby.io.StorageFile

---

canWrite

public boolean canWrite()

Determine whether the named file is writable.

Specified by:

canWrite in interface org.apache.derby.io.StorageFile

---

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 interface org.apache.derby.io.StorageFile

---

delete

public boolean delete()

Deletes the named file or empty directory. This method does not delete non-empty directories.

Specified by:

delete in interface org.apache.derby.io.StorageFile

---

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 org.apache.derby.io.StorageFile

---

getPath

public java.lang.String 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 interface org.apache.derby.io.StorageFile

---

getCanonicalPath

public java.lang.String getCanonicalPath()
                                  throws java.io.IOException

Description copied from interface: org.apache.derby.io.StorageFile

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

Specified by:

getCanonicalPath in interface org.apache.derby.io.StorageFile

---

getName

public java.lang.String getName()

Specified by:

getName in interface org.apache.derby.io.StorageFile

---

createNewFile

public boolean createNewFile()
                      throws java.io.IOException

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 interface org.apache.derby.io.StorageFile

---

renameTo

public boolean renameTo(org.apache.derby.io.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 org.apache.derby.io.StorageFile

---

mkdir

public boolean mkdir()

Creates the named directory.

Specified by:

mkdir in interface org.apache.derby.io.StorageFile

---

mkdirs

public boolean mkdirs()

Creates the named directory, and all nonexistent parent directories.

Specified by:

mkdirs in interface org.apache.derby.io.StorageFile

---

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 org.apache.derby.io.StorageFile

---

getParentDir

public org.apache.derby.io.StorageFile getParentDir()

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

Specified by:

getParentDir in interface org.apache.derby.io.StorageFile

---

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 interface org.apache.derby.io.StorageFile

---

getOutputStream

public java.io.OutputStream getOutputStream()
                                     throws java.io.FileNotFoundException

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 interface org.apache.derby.io.StorageFile

---

getOutputStream

public java.io.OutputStream getOutputStream(boolean append)
                                     throws java.io.FileNotFoundException

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 interface org.apache.derby.io.StorageFile

---

getExclusiveFileLock

public int 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 interface org.apache.derby.io.StorageFile

---

releaseExclusiveFileLock

public void releaseExclusiveFileLock()

Release the resource associated with an earlier acquired exclusive lock

Specified by:

releaseExclusiveFileLock in interface org.apache.derby.io.StorageFile

---

getRandomAccessFile

public org.apache.derby.io.StorageRandomAccessFile getRandomAccessFile(java.lang.String mode)
                                                                throws java.io.FileNotFoundException

Get a random access file.

Specified by:

getRandomAccessFile in interface org.apache.derby.io.StorageFile

---

toString

public java.lang.String toString()

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

Specified by:

toString in interface org.apache.derby.io.StorageFile

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> [ io overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---