org.eclipse.gemini.blueprint.util.internal

Class ClassUtils

java.lang.Object

org.eclipse.gemini.blueprint.util.internal.ClassUtils

public abstract class ClassUtils
extends java.lang.Object

Class utility used internally. Contains mainly class inheritance mechanisms used when creating OSGi service proxies.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	ClassUtils.ClassLoaderBridge Simple class loading abstraction working on both ClassLoader and Bundle classes.
static class	ClassUtils.ClassSet
private static class	ClassUtils.ReadOnlySetFromMap<E>

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.List<java.lang.ClassLoader>	knownNonOsgiLoaders List of special class loaders, outside OSGi, that might be used by the user through boot delegation.
static java.util.Set<java.lang.ClassLoader>	knownNonOsgiLoadersSet Set of special class loaders, outside OSGi, that might be used by the user through boot delegation.

Constructor Summary

Constructors

Constructor and Description
ClassUtils()

Method Summary

Modifier and Type	Method and Description
private static void	addNonOsgiClassLoader(java.lang.ClassLoader classLoader, java.util.List<java.lang.ClassLoader> list, java.util.Map<java.lang.ClassLoader,java.lang.Boolean> map) Special static method used during the class initialization.
static void	configureFactoryForClass(org.springframework.aop.framework.ProxyFactory factory, java.lang.Class<?>[] classes) Based on the given class, properly instructs the ProxyFactory proxies.
static boolean	containsUnrelatedClasses(java.lang.Class<?>[] classes) Determines if multiple classes(not interfaces) are specified, without any relation to each other.
static java.lang.Class<?>[]	excludeClassesWithModifier(java.lang.Class<?>[] classes, int modifier) Excludes classes from the given array, which match the given modifier.
static java.lang.Class<?>[]	getAllInterfaces(java.lang.Class<?> clazz) Gets all interfaces implemented by the given class.
private static java.lang.Class<?>[]	getAllInterfaces(java.lang.Class<?> clazz, java.util.Set<java.lang.Class<?>> interfaces) Gets all the interfaces recursively.
static java.lang.Class<?>[]	getClassHierarchy(java.lang.Class<?> clazz, ClassUtils.ClassSet inclusion) Returns an array of parent classes for the given class.
static java.lang.ClassLoader	getClassLoader(java.lang.Class<?> clazz) Returns the classloader for the given class.
static java.lang.ClassLoader	getFwkClassLoader()
static java.lang.Class<?>	getParticularClass(java.lang.Class<?>[] classes) Returns the first matching class from the given array, that doens't belong to common libraries such as the JDK or OSGi API.
static java.lang.Class<?>[]	getVisibleClasses(java.lang.Class<?>[] classes, org.osgi.framework.Bundle bundle) Given an array of classes, eliminates the ones that cannot be loaded by the given bundle.
static java.lang.Class<?>[]	getVisibleClasses(java.lang.Class<?>[] classes, java.lang.ClassLoader classLoader) Given an array of classes, eliminates the ones that cannot be loaded by the given classloader.
private static java.lang.Class<?>[]	getVisibleClasses(java.lang.Class<?>[] classes, ClassUtils.ClassLoaderBridge loader)
static java.lang.Class<?>[]	getVisibleClassHierarchy(java.lang.Class<?> clazz, ClassUtils.ClassSet inclusion, org.osgi.framework.Bundle bundle) 'Sugar' method that determines the class hierarchy of the given class, returning only the classes visible to the given bundle.
static java.lang.Class<?>[]	getVisibleClassHierarchy(java.lang.Class<?> clazz, ClassUtils.ClassSet inclusion, java.lang.ClassLoader loader) Sugar method that determines the class hierarchy of a given class and then filtering based on the given classloader.
static boolean	isPresent(java.lang.String className, org.osgi.framework.Bundle bundle) Checks the present of a class inside a bundle.
static java.lang.Class<?>[]	loadClasses(java.lang.String[] classNames, java.lang.ClassLoader classLoader) Loads and returns the classes given as names, using the given class loader.
static java.lang.Class<?>[]	loadClassesIfPossible(java.lang.String[] classNames, java.lang.ClassLoader classLoader) Loads classes with the given name, using the given classloader.
static java.lang.Class<?>[]	removeParents(java.lang.Class<?>[] classes) Parses the given class array and eliminate parents of existing classes.
static java.lang.String[]	toStringArray(java.lang.Class<?>[] array) Returns an array of class string names for the given classes.

Methods inherited from class java.lang.Object

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

Field Detail

knownNonOsgiLoaders

public static final java.util.List<java.lang.ClassLoader> knownNonOsgiLoaders

List of special class loaders, outside OSGi, that might be used by the user through boot delegation. read-only.

knownNonOsgiLoadersSet

public static final java.util.Set<java.lang.ClassLoader> knownNonOsgiLoadersSet

Set of special class loaders, outside OSGi, that might be used by the user through boot delegation. read-only.

Constructor Detail

ClassUtils

public ClassUtils()

Method Detail

getFwkClassLoader

public static java.lang.ClassLoader getFwkClassLoader()

addNonOsgiClassLoader

private static void addNonOsgiClassLoader(java.lang.ClassLoader classLoader,
                                          java.util.List<java.lang.ClassLoader> list,
                                          java.util.Map<java.lang.ClassLoader,java.lang.Boolean> map)

Special static method used during the class initialization.

Parameters:

classLoader - non OSGi class loader

getClassHierarchy

public static java.lang.Class<?>[] getClassHierarchy(java.lang.Class<?> clazz,
                                                     ClassUtils.ClassSet inclusion)

Returns an array of parent classes for the given class. The mode paramater indicates whether only interfaces should be included, classes or both. This method is normally used for publishing services and determing the Constants.OBJECTCLASS property.

Note: this method does class expansion returning parent as well as children classes.

Parameters:

clazz -

mode -

Returns:

array of classes extended or implemented by the given class

See Also:

#INCLUDE_ALL_CLASSES, #INCLUDE_CLASS_HIERARCHY, #INCLUDE_INTERFACES

getVisibleClassHierarchy

public static java.lang.Class<?>[] getVisibleClassHierarchy(java.lang.Class<?> clazz,
                                                            ClassUtils.ClassSet inclusion,
                                                            java.lang.ClassLoader loader)

Sugar method that determines the class hierarchy of a given class and then filtering based on the given classloader. If a null classloader, the one of the given class will be used.

Parameters:

clazz -

mode -

loader -

Returns:

getVisibleClassHierarchy

public static java.lang.Class<?>[] getVisibleClassHierarchy(java.lang.Class<?> clazz,
                                                            ClassUtils.ClassSet inclusion,
                                                            org.osgi.framework.Bundle bundle)

'Sugar' method that determines the class hierarchy of the given class, returning only the classes visible to the given bundle.

Parameters:

clazz - the class for which the hierarchy has to be determined

mode - discovery mode

bundle - bundle used for class visibility

Returns:

array of visible classes part of the hierarchy

getVisibleClasses

public static java.lang.Class<?>[] getVisibleClasses(java.lang.Class<?>[] classes,
                                                     java.lang.ClassLoader classLoader)

Given an array of classes, eliminates the ones that cannot be loaded by the given classloader.

Returns:

getVisibleClasses

public static java.lang.Class<?>[] getVisibleClasses(java.lang.Class<?>[] classes,
                                                     org.osgi.framework.Bundle bundle)

Given an array of classes, eliminates the ones that cannot be loaded by the given bundle.

Returns:

getVisibleClasses

private static java.lang.Class<?>[] getVisibleClasses(java.lang.Class<?>[] classes,
                                                      ClassUtils.ClassLoaderBridge loader)

getAllInterfaces

public static java.lang.Class<?>[] getAllInterfaces(java.lang.Class<?> clazz)

Gets all interfaces implemented by the given class. This method returns both parent and children interfaces (i.e. Map and SortedMap).

Parameters:

clazz -

Returns:

all interfaces implemented by the given class.

getAllInterfaces

private static java.lang.Class<?>[] getAllInterfaces(java.lang.Class<?> clazz,
                                                     java.util.Set<java.lang.Class<?>> interfaces)

Gets all the interfaces recursively.

Parameters:

clazz -

interfaces -

Returns:

isPresent

public static boolean isPresent(java.lang.String className,
                                org.osgi.framework.Bundle bundle)

Checks the present of a class inside a bundle. This method returns true if the given bundle can load the given class or false otherwise.

Parameters:

className -

bundle -

Returns:

getClassLoader

public static java.lang.ClassLoader getClassLoader(java.lang.Class<?> clazz)

Returns the classloader for the given class. This method deals with JDK classes which return by default, a null classloader.

Parameters:

clazz -

Returns:

toStringArray

public static java.lang.String[] toStringArray(java.lang.Class<?>[] array)

Returns an array of class string names for the given classes.

Parameters:

array -

Returns:

containsUnrelatedClasses

public static boolean containsUnrelatedClasses(java.lang.Class<?>[] classes)

Determines if multiple classes(not interfaces) are specified, without any relation to each other. Interfaces will simply be ignored.

Parameters:

classes - an array of classes

Returns:

true if at least two classes unrelated to each other are found, false otherwise

removeParents

public static java.lang.Class<?>[] removeParents(java.lang.Class<?>[] classes)

Parses the given class array and eliminate parents of existing classes. Useful when creating proxies to minimize the number of implemented interfaces and redundant class information.

Parameters:

classes - array of classes

Returns:

a new array without superclasses

See Also:

containsUnrelatedClasses(Class[]), configureFactoryForClass(ProxyFactory, Class[])

configureFactoryForClass

public static void configureFactoryForClass(org.springframework.aop.framework.ProxyFactory factory,
                                            java.lang.Class<?>[] classes)

Based on the given class, properly instructs the ProxyFactory proxies. For additional sanity checks on the passed classes, check the methods below.

Parameters:

factory -

classes -

See Also:

containsUnrelatedClasses(Class[]), removeParents(Class[])

loadClassesIfPossible

public static java.lang.Class<?>[] loadClassesIfPossible(java.lang.String[] classNames,
                                                         java.lang.ClassLoader classLoader)

Loads classes with the given name, using the given classloader. ClassNotFoundException exceptions are being ignored. The return class array will not contain duplicates.

Parameters:

classNames - array of classnames to load (in FQN format)

classLoader - classloader used for loading the classes

Returns:

an array of classes (can be smaller then the array of class names) w/o duplicates

loadClasses

public static java.lang.Class<?>[] loadClasses(java.lang.String[] classNames,
                                               java.lang.ClassLoader classLoader)

Loads and returns the classes given as names, using the given class loader. Throws IllegalArgument exception if the classes cannot be loaded.

Parameters:

classNames - array of class names

classLoader - class loader for loading the classes

Returns:

the loaded classes

excludeClassesWithModifier

public static java.lang.Class<?>[] excludeClassesWithModifier(java.lang.Class<?>[] classes,
                                                              int modifier)

Excludes classes from the given array, which match the given modifier.

Parameters:

classes - array of classes (can be null)

modifier - class modifier

Returns:

array of classes (w/o duplicates) which does not have the given modifier

See Also:

Modifier

getParticularClass

public static java.lang.Class<?> getParticularClass(java.lang.Class<?>[] classes)

Returns the first matching class from the given array, that doens't belong to common libraries such as the JDK or OSGi API. Useful for filtering OSGi services by type to prevent class cast problems.

No sanity checks are done on the given array class.

Parameters:

classes - array of classes

Returns:

a 'particular' (non JDK/OSGi) class if one is found. Else the first available entry is returned.