weka.core

Class ClassDiscovery

java.lang.Object

weka.core.ClassDiscovery

All Implemented Interfaces:

RevisionHandler

public class ClassDiscovery
extends Object
implements RevisionHandler

This class is used for discovering classes that implement a certain interface or a derived from a certain class.

Version:

$Revision: 5377 $

Author:

FracPete (fracpete at waikato dot ac dot nz)

See Also:

ClassDiscovery.StringCompare

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ClassDiscovery.StringCompare compares two strings.

Field Summary

Fields

Modifier and Type	Field and Description
protected static Hashtable<String,Vector>	m_Cache for caching queries (classname+packagename <-> Vector with classnames).
static boolean	VERBOSE whether to output some debug information.

Constructor Summary

Constructors

Constructor and Description
ClassDiscovery()

Method Summary

Modifier and Type	Method and Description
protected static void	addCache(Class cls, String pkgname, Vector classnames) adds the list of classnames to the cache.
static void	clearCache() clears the cache for class/classnames relation.
static Vector	find(Class cls, String pkgname) Checks the given package for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.
static Vector	find(Class cls, String[] pkgnames) Checks the given packages for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.
static Vector	find(String classname, String pkgname) Checks the given package for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.
static Vector	find(String classname, String[] pkgnames) Checks the given packages for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.
static Vector	findPackages() Lists all packages it can find in the classpath.
protected static Vector	getCache(Class cls, String pkgname) returns the list of classnames associated with this class and package, if available, otherwise null.
String	getRevision() Returns the revision string.
protected static HashSet	getSubDirectories(String prefix, File dir, HashSet list) adds all the sub-directories recursively to the list.
protected static URL	getURL(String classpathPart, String pkgname) If the given package can be found in this part of the classpath then an URL object is returned, otherwise null.
static boolean	hasInterface(Class intf, Class cls) Checks whether the given class implements the given interface.
static boolean	hasInterface(String intf, String cls) Checks whether the given class implements the given interface.
protected static void	initCache() initializes the cache for the classnames.
static boolean	isSubclass(Class superclass, Class otherclass) Checks whether the "otherclass" is a subclass of the given "superclass".
static boolean	isSubclass(String superclass, String otherclass) Checks whether the "otherclass" is a subclass of the given "superclass".
static void	main(String[] args) Possible calls: weka.core.ClassDiscovery <packages> Prints all the packages in the current classpath weka.core.ClassDiscovery <classname> <packagename(s)> Prints the classes it found.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VERBOSE

public static final boolean VERBOSE

whether to output some debug information.

See Also:

Constant Field Values

m_Cache

protected static Hashtable<String,Vector> m_Cache

for caching queries (classname+packagename <-> Vector with classnames).

Constructor Detail

ClassDiscovery

public ClassDiscovery()

Method Detail

isSubclass

public static boolean isSubclass(String superclass,
                                 String otherclass)

Checks whether the "otherclass" is a subclass of the given "superclass".

Parameters:

superclass - the superclass to check against

otherclass - this class is checked whether it is a subclass of the the superclass

Returns:

TRUE if "otherclass" is a true subclass

isSubclass

public static boolean isSubclass(Class superclass,
                                 Class otherclass)

Checks whether the "otherclass" is a subclass of the given "superclass".

Parameters:

superclass - the superclass to check against

otherclass - this class is checked whether it is a subclass of the the superclass

Returns:

TRUE if "otherclass" is a true subclass

hasInterface

public static boolean hasInterface(String intf,
                                   String cls)

Checks whether the given class implements the given interface.

Parameters:

intf - the interface to look for in the given class

cls - the class to check for the interface

Returns:

TRUE if the class contains the interface

hasInterface

public static boolean hasInterface(Class intf,
                                   Class cls)

Checks whether the given class implements the given interface.

Parameters:

intf - the interface to look for in the given class

cls - the class to check for the interface

Returns:

TRUE if the class contains the interface

getURL

protected static URL getURL(String classpathPart,
                            String pkgname)

If the given package can be found in this part of the classpath then an URL object is returned, otherwise null.

Parameters:

classpathPart - the part of the classpath to look for the package

pkgname - the package to look for

Returns:

if found, the url as string, otherwise null

find

public static Vector find(String classname,
                          String[] pkgnames)

Checks the given packages for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.

Parameters:

classname - the class/interface to look for

pkgnames - the packages to search in

Returns:

a list with all the found classnames

find

public static Vector find(String classname,
                          String pkgname)

Checks the given package for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.

Parameters:

classname - the class/interface to look for

pkgname - the package to search in

Returns:

a list with all the found classnames

find

public static Vector find(Class cls,
                          String[] pkgnames)

Checks the given packages for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.

Parameters:

cls - the class/interface to look for

pkgnames - the packages to search in

Returns:

a list with all the found classnames

find

public static Vector find(Class cls,
                          String pkgname)

Checks the given package for classes that inherited from the given class, in case it's a class, or implement this class, in case it's an interface.

Parameters:

cls - the class/interface to look for

pkgname - the package to search in

Returns:

a list with all the found classnames

getSubDirectories

protected static HashSet getSubDirectories(String prefix,
                                           File dir,
                                           HashSet list)

adds all the sub-directories recursively to the list.

Parameters:

prefix - the path prefix

dir - the directory to look in for sub-dirs

list - the current list of sub-dirs

Returns:

the new list of sub-dirs

findPackages

public static Vector findPackages()

Lists all packages it can find in the classpath.

Returns:

a list with all the found packages

initCache

protected static void initCache()

initializes the cache for the classnames.

addCache

protected static void addCache(Class cls,
                               String pkgname,
                               Vector classnames)

adds the list of classnames to the cache.

Parameters:

cls - the class to cache the classnames for

pkgname - the package name the classes were found in

classnames - the list of classnames to cache

getCache

protected static Vector getCache(Class cls,
                                 String pkgname)

returns the list of classnames associated with this class and package, if available, otherwise null.

Parameters:

cls - the class to get the classnames for

pkgname - the package name for the classes

Returns:

the classnames if found, otherwise null

clearCache

public static void clearCache()

clears the cache for class/classnames relation.

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

public static void main(String[] args)

Possible calls:

• weka.core.ClassDiscovery <packages>
  Prints all the packages in the current classpath
• weka.core.ClassDiscovery <classname> <packagename(s)>
  Prints the classes it found.

Parameters:

args - the commandline arguments