nz.ac.waikato.cms.locator

Class ClassLocator

java.lang.Object

nz.ac.waikato.cms.locator.ClassLocator

All Implemented Interfaces:

java.io.Serializable

public class ClassLocator
extends java.lang.Object
implements java.io.Serializable

This class is used for discovering classes that implement a certain interface or a derived from a certain class. Based on the weka.core.ClassDiscovery class.
Use "nz.ac.waikato.cms.locator.ClassLocator.LOGLEVEL" with a value of "{OFF|SEVERE|WARNING|INFO|CONFIG|FINE|FINER|FINEST}" to set custom logging level.

Author:

FracPete (fracpete at waikato dot ac dot nz)

See Also:

StringCompare, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.HashSet<java.lang.String>	m_BlackListed for caching failed instantiations (classnames).
protected ClassCache	m_Cache the overall class cache.
protected java.util.HashMap<java.lang.String,java.util.List<java.lang.Class>>	m_CacheClasses for caching queries (classname-packagename <-> List with classes).
protected java.util.HashMap<java.lang.String,java.util.List<java.lang.String>>	m_CacheNames for caching queries (classname-packagename <-> List with classnames).
protected static java.util.Map<java.lang.String,java.lang.Boolean>	m_CheckInterface the cache for interface checks.
protected static java.util.Map<java.lang.String,java.lang.Boolean>	m_CheckSubClass the cache for subclass checks.
protected java.util.logging.Logger	m_Logger the logger in use.
protected boolean	m_OnlyDefaultConstructor whether to allow only classes with the default constructor.
protected boolean	m_OnlySerializable whether to allow only serializable classes.
protected static java.util.Map<java.lang.Class<? extends ClassTraversal>,ClassLocator>	m_Singleton the singleton.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ClassLocator() Initializes the class locator.
protected	ClassLocator(ClassTraversal traversal) Initializes the class locator.

Method Summary

Modifier and Type	Method and Description
protected void	addCache(java.lang.Class cls, java.lang.String pkgname, java.util.List<java.lang.String> classnames, java.util.List<java.lang.Class> classes) adds the list of classnames to the cache.
protected void	blacklist(java.lang.String classname) Blacklists the given classname.
java.util.List<java.net.URL>	classpathPartsForClass(java.lang.Class cls) Returns the classpath parts that contain the specified class (eg to find duplicates).
java.util.List<java.net.URL>	classpathPartsForClass(java.lang.String classname) Returns the classpath parts that contain the specified class (eg to find duplicates).
java.util.List<java.lang.Class>	findClasses(java.lang.Class cls, java.lang.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.
java.util.List<java.lang.Class>	findClasses(java.lang.String classname, java.lang.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.
java.util.List<java.lang.Class>	findClassesInPackage(java.lang.Class cls, java.lang.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.
java.util.List<java.lang.Class>	findClassesInPackage(java.lang.String classname, java.lang.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.
java.util.List<java.lang.String>	findNames(java.lang.Class cls, java.lang.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.
java.util.List<java.lang.String>	findNames(java.lang.String classname, java.lang.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.
java.util.List<java.lang.String>	findNamesInPackage(java.lang.Class cls, java.lang.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.
java.util.List<java.lang.String>	findNamesInPackage(java.lang.String classname, java.lang.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.
java.util.List<java.lang.String>	findPackages() Lists all packages it can find in the classpath.
ClassCache	getCache() Returns the class cache.
protected java.util.List<java.lang.Class>	getClassCache(java.lang.Class cls, java.lang.String pkgname) returns the list of classes associated with this class and package, if available, otherwise null.
java.util.logging.Logger	getLogger() Returns the logger in use.
protected java.util.List<java.lang.String>	getNameCache(java.lang.Class cls, java.lang.String pkgname) returns the list of classnames associated with this class and package, if available, otherwise null.
static ClassLocator	getSingleton() Returns the singleton, instantiates it if necessary.
static ClassLocator	getSingleton(ClassTraversal traversal) Returns the singleton, instantiates it if necessary.
static boolean	hasInterface(java.lang.Class intf, java.lang.Class cls) Checks whether the given class implements the given interface.
static boolean	hasInterface(java.lang.String intf, java.lang.String cls) Checks whether the given class implements the given interface.
protected void	initCache(ClassTraversal traversal) initializes the cache for the classnames.
boolean	isBlacklisted(java.lang.String classname) Returns whether this classname has been blacklisted.
boolean	isLoggingEnabled() Returns whether logging is enabled.
boolean	isOnlyDefaultConstructor() Returns whether to allow only classes with default constructor.
boolean	isOnlySerializable() Returns whether to allow only serializable classes.
static boolean	isSubclass(java.lang.Class superclass, java.lang.Class otherclass) Checks whether the "otherclass" is a subclass of the given "superclass".
static boolean	isSubclass(java.lang.String superclass, java.lang.String otherclass) Checks whether the "otherclass" is a subclass of the given "superclass".
static void	main(java.lang.String[] args) Possible calls: adams.core.ClassLocator <packages> Prints all the packages in the current classpath adams.core.ClassLocator <classname> <packagename(s)> Prints the classes it found.
static boolean	matches(java.lang.Class superclassOrIntf, java.lang.Class otherclass) Checks whether the "otherclass" is a subclass of the given "superclassOrIntf" or whether it implements "superclassOrIntf".
static boolean	matches(java.lang.String superclassOrIntf, java.lang.String otherclass) Checks whether the "otherclass" is a subclass of the given "superclassOrIntf" or whether it implements "superclassOrIntf".
protected ClassCache	newClassCache(ClassTraversal traversal) Returns a new instance of the ClassCache.
void	setOnlyDefaultConstructor(boolean value) Sets whether to allow only classes with default constructor.
void	setOnlySerializable(boolean value) Sets whether to allow only serializable classes.

Methods inherited from class java.lang.Object

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

Field Detail

m_CheckSubClass

protected static java.util.Map<java.lang.String,java.lang.Boolean> m_CheckSubClass

the cache for subclass checks.

m_CheckInterface

protected static java.util.Map<java.lang.String,java.lang.Boolean> m_CheckInterface

the cache for interface checks.

m_Logger

protected transient java.util.logging.Logger m_Logger

the logger in use.

m_CacheNames

protected java.util.HashMap<java.lang.String,java.util.List<java.lang.String>> m_CacheNames

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

m_CacheClasses

protected java.util.HashMap<java.lang.String,java.util.List<java.lang.Class>> m_CacheClasses

for caching queries (classname-packagename <-> List with classes).

m_BlackListed

protected java.util.HashSet<java.lang.String> m_BlackListed

for caching failed instantiations (classnames).

m_Cache

protected ClassCache m_Cache

the overall class cache.

m_OnlyDefaultConstructor

protected boolean m_OnlyDefaultConstructor

whether to allow only classes with the default constructor.

m_OnlySerializable

protected boolean m_OnlySerializable

whether to allow only serializable classes.

m_Singleton

protected static java.util.Map<java.lang.Class<? extends ClassTraversal>,ClassLocator> m_Singleton

the singleton.

Constructor Detail

ClassLocator

protected ClassLocator()

Initializes the class locator. Uses default traversal scheme for initalizing the class cache.

ClassLocator

protected ClassLocator(ClassTraversal traversal)

Initializes the class locator. Uses the specified traversal scheme for initializing the class cache.

Parameters:

traversal - the traversal instance to use, can be null

Method Detail

isLoggingEnabled

public boolean isLoggingEnabled()

Returns whether logging is enabled.

Returns:

true if enabled

getLogger

public java.util.logging.Logger getLogger()

Returns the logger in use.

Returns:

the logger

setOnlyDefaultConstructor

public void setOnlyDefaultConstructor(boolean value)

Sets whether to allow only classes with default constructor.

Parameters:

value - true if only default allowed

isOnlyDefaultConstructor

public boolean isOnlyDefaultConstructor()

Returns whether to allow only classes with default constructor.

Returns:

true if only default allowed

setOnlySerializable

public void setOnlySerializable(boolean value)

Sets whether to allow only serializable classes.

Parameters:

value - true if only serializable

isOnlySerializable

public boolean isOnlySerializable()

Returns whether to allow only serializable classes.

Returns:

true if only serializable

findNames

public java.util.List<java.lang.String> findNames(java.lang.String classname,
                                                  java.lang.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

findClasses

public java.util.List<java.lang.Class> findClasses(java.lang.String classname,
                                                   java.lang.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 classes

findNames

public java.util.List<java.lang.String> findNames(java.lang.Class cls,
                                                  java.lang.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

findClasses

public java.util.List<java.lang.Class> findClasses(java.lang.Class cls,
                                                   java.lang.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 classes

findNamesInPackage

public java.util.List<java.lang.String> findNamesInPackage(java.lang.String classname,
                                                           java.lang.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

findClassesInPackage

public java.util.List<java.lang.Class> findClassesInPackage(java.lang.String classname,
                                                            java.lang.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 classes

findNamesInPackage

public java.util.List<java.lang.String> findNamesInPackage(java.lang.Class cls,
                                                           java.lang.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

findClassesInPackage

public java.util.List<java.lang.Class> findClassesInPackage(java.lang.Class cls,
                                                            java.lang.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 classes

findPackages

public java.util.List<java.lang.String> findPackages()

Lists all packages it can find in the classpath.

Returns:

a list with all the found packages

classpathPartsForClass

public java.util.List<java.net.URL> classpathPartsForClass(java.lang.Class cls)

Returns the classpath parts that contain the specified class (eg to find duplicates).

Parameters:

cls - the class to look for

Returns:

the parts of the classpath the class was located in

classpathPartsForClass

public java.util.List<java.net.URL> classpathPartsForClass(java.lang.String classname)

Returns the classpath parts that contain the specified class (eg to find duplicates).

Parameters:

classname - the class to look for

Returns:

the parts of the classpath the class was located in

newClassCache

protected ClassCache newClassCache(ClassTraversal traversal)

Returns a new instance of the ClassCache.

Parameters:

traversal - how to traverse the classes, can be null

Returns:

the instance

initCache

protected void initCache(ClassTraversal traversal)

initializes the cache for the classnames.

Parameters:

traversal - how to traverse the classes, can be null

addCache

protected void addCache(java.lang.Class cls,
                        java.lang.String pkgname,
                        java.util.List<java.lang.String> classnames,
                        java.util.List<java.lang.Class> classes)

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

getNameCache

protected java.util.List<java.lang.String> getNameCache(java.lang.Class cls,
                                                        java.lang.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

getClassCache

protected java.util.List<java.lang.Class> getClassCache(java.lang.Class cls,
                                                        java.lang.String pkgname)

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

Parameters:

cls - the class to get the classes for

pkgname - the package name for the classes

Returns:

the classes if found, otherwise null

blacklist

protected void blacklist(java.lang.String classname)

Blacklists the given classname.

Parameters:

classname - the classname to blacklist

isBlacklisted

public boolean isBlacklisted(java.lang.String classname)

Returns whether this classname has been blacklisted.

Parameters:

classname - the classname to check

Returns:

true if blacklisted

getCache

public ClassCache getCache()

Returns the class cache.

Returns:

the cache

getSingleton

public static ClassLocator getSingleton()

Returns the singleton, instantiates it if necessary.

Returns:

the singleton

getSingleton

public static ClassLocator getSingleton(ClassTraversal traversal)

Returns the singleton, instantiates it if necessary.

Parameters:

traversal - the class traversal scheme to use, can be null for default one

Returns:

the singleton

isSubclass

public static boolean isSubclass(java.lang.String superclass,
                                 java.lang.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(java.lang.Class superclass,
                                 java.lang.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(java.lang.String intf,
                                   java.lang.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(java.lang.Class intf,
                                   java.lang.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

matches

public static boolean matches(java.lang.String superclassOrIntf,
                              java.lang.String otherclass)

Checks whether the "otherclass" is a subclass of the given "superclassOrIntf" or whether it implements "superclassOrIntf".

Parameters:

superclassOrIntf - the superclass/interface 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 or implements the interface

matches

public static boolean matches(java.lang.Class superclassOrIntf,
                              java.lang.Class otherclass)

Checks whether the "otherclass" is a subclass of the given "superclassOrIntf" or whether it implements "superclassOrIntf".

Parameters:

superclassOrIntf - the superclass/interface 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 or implements the interface

main

public static void main(java.lang.String[] args)

Possible calls:

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

Parameters:

args - the commandline arguments