org.springframework.util

Class ClassUtils

java.lang.Object

org.springframework.util.ClassUtils

public abstract class ClassUtils
extends Object

Miscellaneous class utility methods. Mainly for internal use within the framework.

Since:

1.1

Author:

Juergen Hoeller, Keith Donald, Rob Harrop, Sam Brannen

See Also:

TypeUtils, ReflectionUtils

Field Summary

Fields

Modifier and Type	Field and Description
static String	ARRAY_SUFFIX Suffix for array class names: "[]"
static String	CGLIB_CLASS_SEPARATOR The CGLIB class separator character "$$"
static String	CLASS_FILE_SUFFIX The ".class" file suffix

Constructor Summary

Constructors

Constructor and Description
ClassUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static String	addResourcePathToPackagePath(Class<?> clazz, String resourceName) Return a path suitable for use with ClassLoader.getResource (also suitable for use with Class.getResource by prepending a slash ('/') to the return value).
static String	classNamesToString(Class... classes) Build a String that consists of the names of the classes/interfaces in the given array.
static String	classNamesToString(Collection<Class> classes) Build a String that consists of the names of the classes/interfaces in the given collection.
static String	classPackageAsResourcePath(Class<?> clazz) Given an input class object, return a string which consists of the class's package name as a pathname, i.e., all dots ('.') are replaced by slashes ('/').
static String	convertClassNameToResourcePath(String className) Convert a "."-based fully qualified class name to a "/"-based resource path.
static String	convertResourcePathToClassName(String resourcePath) Convert a "/"-based resource path to a "."-based fully qualified class name.
static Class<?>	createCompositeInterface(Class<?>[] interfaces, ClassLoader classLoader) Create a composite interface Class for the given interfaces, implementing the given interfaces in one single Class.
static Class<?>	determineCommonAncestor(Class<?> clazz1, Class<?> clazz2) Determine the common ancestor of the given classes, if any.
static Class<?>	forName(String name) Deprecated. as of Spring 3.0, in favor of specifying a ClassLoader explicitly: see forName(String, ClassLoader)
static Class<?>	forName(String name, ClassLoader classLoader) Replacement for Class.forName() that also returns Class instances for primitives (e.g.
static Class<?>[]	getAllInterfaces(Object instance) Return all interfaces that the given instance implements as array, including ones implemented by superclasses.
static Set<Class>	getAllInterfacesAsSet(Object instance) Return all interfaces that the given instance implements as Set, including ones implemented by superclasses.
static Class<?>[]	getAllInterfacesForClass(Class<?> clazz) Return all interfaces that the given class implements as array, including ones implemented by superclasses.
static Class<?>[]	getAllInterfacesForClass(Class<?> clazz, ClassLoader classLoader) Return all interfaces that the given class implements as array, including ones implemented by superclasses.
static Set<Class>	getAllInterfacesForClassAsSet(Class clazz) Return all interfaces that the given class implements as Set, including ones implemented by superclasses.
static Set<Class>	getAllInterfacesForClassAsSet(Class clazz, ClassLoader classLoader) Return all interfaces that the given class implements as Set, including ones implemented by superclasses.
static String	getClassFileName(Class<?> clazz) Determine the name of the class file, relative to the containing package: e.g.
static <T> Constructor<T>	getConstructorIfAvailable(Class<T> clazz, Class<?>... paramTypes) Determine whether the given class has a public constructor with the given signature, and return it if available (else return null).
static ClassLoader	getDefaultClassLoader() Return the default ClassLoader to use: typically the thread context ClassLoader, if available; the ClassLoader that loaded the ClassUtils class will be used as fallback.
static String	getDescriptiveType(Object value) Return a descriptive name for the given object's type: usually simply the class name, but component type class name + "[]" for arrays, and an appended list of implemented interfaces for JDK proxies.
static Method	getMethod(Class<?> clazz, String methodName, Class<?>... paramTypes) Determine whether the given class has a public method with the given signature, and return it if available (else throws an IllegalStateException).
static int	getMethodCountForName(Class<?> clazz, String methodName) Return the number of methods with a given name (with any argument types), for the given class and/or its superclasses.
static Method	getMethodIfAvailable(Class<?> clazz, String methodName, Class<?>... paramTypes) Determine whether the given class has a public method with the given signature, and return it if available (else return null).
static Method	getMostSpecificMethod(Method method, Class<?> targetClass) Given a method, which may come from an interface, and a target class used in the current reflective invocation, find the corresponding target method if there is one.
static String	getPackageName(Class<?> clazz) Determine the name of the package of the given class, e.g.
static String	getPackageName(String fqClassName) Determine the name of the package of the given fully-qualified class name, e.g.
static String	getQualifiedMethodName(Method method) Return the qualified name of the given method, consisting of fully qualified interface/class name + "." + method name.
static String	getQualifiedName(Class<?> clazz) Return the qualified name of the given class: usually simply the class name, but component type class name + "[]" for arrays.
static String	getShortName(Class<?> clazz) Get the class name without the qualified package name.
static String	getShortName(String className) Get the class name without the qualified package name.
static String	getShortNameAsProperty(Class<?> clazz) Return the short string name of a Java class in uncapitalized JavaBeans property format.
static Method	getStaticMethod(Class<?> clazz, String methodName, Class<?>... args) Return a public static method of a class.
static Class<?>	getUserClass(Class<?> clazz) Return the user-defined class for the given class: usually simply the given class, but the original class in case of a CGLIB-generated subclass.
static Class<?>	getUserClass(Object instance) Return the user-defined class for the given instance: usually simply the class of the given instance, but the original class in case of a CGLIB-generated subclass.
static boolean	hasAtLeastOneMethodWithName(Class<?> clazz, String methodName) Does the given class or one of its superclasses at least have one or more methods with the supplied name (with any argument types)? Includes non-public methods.
static boolean	hasConstructor(Class<?> clazz, Class<?>... paramTypes) Determine whether the given class has a public constructor with the given signature.
static boolean	hasMethod(Class<?> clazz, String methodName, Class<?>... paramTypes) Determine whether the given class has a public method with the given signature.
static boolean	isAssignable(Class<?> lhsType, Class<?> rhsType) Check if the right-hand side type may be assigned to the left-hand side type, assuming setting by reflection.
static boolean	isAssignableValue(Class<?> type, Object value) Determine if the given type is assignable from the given value, assuming setting by reflection.
static boolean	isCacheSafe(Class<?> clazz, ClassLoader classLoader) Check whether the given class is cache-safe in the given context, i.e.
static boolean	isCglibProxy(Object object) Check whether the given object is a CGLIB proxy.
static boolean	isCglibProxyClass(Class<?> clazz) Check whether the specified class is a CGLIB-generated class.
static boolean	isCglibProxyClassName(String className) Check whether the specified class name is a CGLIB-generated class.
static boolean	isPresent(String className) Deprecated. as of Spring 2.5, in favor of isPresent(String, ClassLoader)
static boolean	isPresent(String className, ClassLoader classLoader) Determine whether the Class identified by the supplied name is present and can be loaded.
static boolean	isPrimitiveArray(Class<?> clazz) Check if the given class represents an array of primitives, i.e.
static boolean	isPrimitiveOrWrapper(Class<?> clazz) Check if the given class represents a primitive (i.e.
static boolean	isPrimitiveWrapper(Class<?> clazz) Check if the given class represents a primitive wrapper, i.e.
static boolean	isPrimitiveWrapperArray(Class<?> clazz) Check if the given class represents an array of primitive wrappers, i.e.
static boolean	isVisible(Class<?> clazz, ClassLoader classLoader) Check whether the given class is visible in the given ClassLoader.
static boolean	matchesTypeName(Class<?> clazz, String typeName) Check whether the given class matches the user-specified type name.
static ClassLoader	overrideThreadContextClassLoader(ClassLoader classLoaderToUse) Override the thread context ClassLoader with the environment's bean ClassLoader if necessary, i.e.
static Class<?>	resolveClassName(String className, ClassLoader classLoader) Resolve the given class name into a Class instance.
static Class<?>	resolvePrimitiveClassName(String name) Resolve the given class name as primitive class, if appropriate, according to the JVM's naming rules for primitive classes.
static Class<?>	resolvePrimitiveIfNecessary(Class<?> clazz) Resolve the given class if it is a primitive class, returning the corresponding primitive wrapper type instead.
static Class<?>[]	toClassArray(Collection<Class<?>> collection) Copy the given Collection into a Class array.

Methods inherited from class java.lang.Object

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

Field Detail

ARRAY_SUFFIX

public static final String ARRAY_SUFFIX

Suffix for array class names: "[]"

See Also:

Constant Field Values

CGLIB_CLASS_SEPARATOR

public static final String CGLIB_CLASS_SEPARATOR

The CGLIB class separator character "$$"

See Also:

Constant Field Values

CLASS_FILE_SUFFIX

public static final String CLASS_FILE_SUFFIX

The ".class" file suffix

See Also:

Constant Field Values

Constructor Detail

ClassUtils

public ClassUtils()

Method Detail

getDefaultClassLoader

public static ClassLoader getDefaultClassLoader()

Return the default ClassLoader to use: typically the thread context ClassLoader, if available; the ClassLoader that loaded the ClassUtils class will be used as fallback.

Call this method if you intend to use the thread context ClassLoader in a scenario where you clearly prefer a non-null ClassLoader reference: for example, for class path resource loading (but not necessarily for Class.forName, which accepts a null ClassLoader reference as well).

Returns:

the default ClassLoader (only null if even the system ClassLoader isn't accessible)

See Also:

Thread.getContextClassLoader(), ClassLoader.getSystemClassLoader()

overrideThreadContextClassLoader

public static ClassLoader overrideThreadContextClassLoader(ClassLoader classLoaderToUse)

Override the thread context ClassLoader with the environment's bean ClassLoader if necessary, i.e. if the bean ClassLoader is not equivalent to the thread context ClassLoader already.

Parameters:

classLoaderToUse - the actual ClassLoader to use for the thread context

Returns:

the original thread context ClassLoader, or null if not overridden

forName

@Deprecated
public static Class<?> forName(String name)
                        throws ClassNotFoundException,
                               LinkageError

Deprecated. as of Spring 3.0, in favor of specifying a ClassLoader explicitly: see forName(String, ClassLoader)

Replacement for Class.forName() that also returns Class instances for primitives (like "int") and array class names (like "String[]").

Always uses the default class loader: that is, preferably the thread context class loader, or the ClassLoader that loaded the ClassUtils class as fallback.

Parameters:

name - the name of the Class

Returns:

Class instance for the supplied name

Throws:

ClassNotFoundException - if the class was not found

LinkageError - if the class file could not be loaded

See Also:

Class.forName(String, boolean, ClassLoader), getDefaultClassLoader()

forName

public static Class<?> forName(String name,
               ClassLoader classLoader)
                        throws ClassNotFoundException,
                               LinkageError

Replacement for Class.forName() that also returns Class instances for primitives (e.g. "int") and array class names (e.g. "String[]"). Furthermore, it is also capable of resolving inner class names in Java source style (e.g. "java.lang.Thread.State" instead of "java.lang.Thread$State").

Parameters:

name - the name of the Class

classLoader - the class loader to use (may be null, which indicates the default class loader)

Returns:

Class instance for the supplied name

Throws:

ClassNotFoundException - if the class was not found

LinkageError - if the class file could not be loaded

See Also:

Class.forName(String, boolean, ClassLoader)

resolveClassName

public static Class<?> resolveClassName(String className,
                        ClassLoader classLoader)
                                 throws IllegalArgumentException

Resolve the given class name into a Class instance. Supports primitives (like "int") and array class names (like "String[]").

This is effectively equivalent to the forName method with the same arguments, with the only difference being the exceptions thrown in case of class loading failure.

Parameters:

className - the name of the Class

classLoader - the class loader to use (may be null, which indicates the default class loader)

Returns:

Class instance for the supplied name

Throws:

IllegalArgumentException - if the class name was not resolvable (that is, the class could not be found or the class file could not be loaded)

See Also:

forName(String, ClassLoader)

resolvePrimitiveClassName

public static Class<?> resolvePrimitiveClassName(String name)

Resolve the given class name as primitive class, if appropriate, according to the JVM's naming rules for primitive classes.

Also supports the JVM's internal class names for primitive arrays. Does not support the "[]" suffix notation for primitive arrays; this is only supported by forName(String, ClassLoader).

Parameters:

name - the name of the potentially primitive class

Returns:

the primitive class, or null if the name does not denote a primitive class or primitive array class

isPresent

@Deprecated
public static boolean isPresent(String className)

Deprecated. as of Spring 2.5, in favor of isPresent(String, ClassLoader)

Determine whether the Class identified by the supplied name is present and can be loaded. Will return false if either the class or one of its dependencies is not present or cannot be loaded.

Parameters:

className - the name of the class to check

Returns:

whether the specified class is present

isPresent

public static boolean isPresent(String className,
                ClassLoader classLoader)

Determine whether the Class identified by the supplied name is present and can be loaded. Will return false if either the class or one of its dependencies is not present or cannot be loaded.

Parameters:

className - the name of the class to check

classLoader - the class loader to use (may be null, which indicates the default class loader)

Returns:

whether the specified class is present

getUserClass

public static Class<?> getUserClass(Object instance)

Return the user-defined class for the given instance: usually simply the class of the given instance, but the original class in case of a CGLIB-generated subclass.

Parameters:

instance - the instance to check

Returns:

the user-defined class

getUserClass

public static Class<?> getUserClass(Class<?> clazz)

Return the user-defined class for the given class: usually simply the given class, but the original class in case of a CGLIB-generated subclass.

Parameters:

clazz - the class to check

Returns:

the user-defined class

isCacheSafe

public static boolean isCacheSafe(Class<?> clazz,
                  ClassLoader classLoader)

Check whether the given class is cache-safe in the given context, i.e. whether it is loaded by the given ClassLoader or a parent of it.

Parameters:

clazz - the class to analyze

classLoader - the ClassLoader to potentially cache metadata in

getShortName

public static String getShortName(String className)

Get the class name without the qualified package name.

Parameters:

className - the className to get the short name for

Returns:

the class name of the class without the package name

Throws:

IllegalArgumentException - if the className is empty

getShortName

public static String getShortName(Class<?> clazz)

Get the class name without the qualified package name.

Parameters:

clazz - the class to get the short name for

Returns:

the class name of the class without the package name

getShortNameAsProperty

public static String getShortNameAsProperty(Class<?> clazz)

Return the short string name of a Java class in uncapitalized JavaBeans property format. Strips the outer class name in case of an inner class.

Parameters:

clazz - the class

Returns:

the short name rendered in a standard JavaBeans property format

See Also:

Introspector.decapitalize(String)

getClassFileName

public static String getClassFileName(Class<?> clazz)

Determine the name of the class file, relative to the containing package: e.g. "String.class"

Parameters:

clazz - the class

Returns:

the file name of the ".class" file

getPackageName

public static String getPackageName(Class<?> clazz)

Determine the name of the package of the given class, e.g. "java.lang" for the java.lang.String class.

Parameters:

clazz - the class

Returns:

the package name, or the empty String if the class is defined in the default package

getPackageName

public static String getPackageName(String fqClassName)

Determine the name of the package of the given fully-qualified class name, e.g. "java.lang" for the java.lang.String class name.

Parameters:

fqClassName - the fully-qualified class name

Returns:

the package name, or the empty String if the class is defined in the default package

getQualifiedName

public static String getQualifiedName(Class<?> clazz)

Return the qualified name of the given class: usually simply the class name, but component type class name + "[]" for arrays.

Parameters:

clazz - the class

Returns:

the qualified name of the class

getQualifiedMethodName

public static String getQualifiedMethodName(Method method)

Return the qualified name of the given method, consisting of fully qualified interface/class name + "." + method name.

Parameters:

method - the method

Returns:

the qualified name of the method

getDescriptiveType

public static String getDescriptiveType(Object value)

Return a descriptive name for the given object's type: usually simply the class name, but component type class name + "[]" for arrays, and an appended list of implemented interfaces for JDK proxies.

Parameters:

value - the value to introspect

Returns:

the qualified name of the class

matchesTypeName

public static boolean matchesTypeName(Class<?> clazz,
                      String typeName)

Check whether the given class matches the user-specified type name.

Parameters:

clazz - the class to check

typeName - the type name to match

hasConstructor

public static boolean hasConstructor(Class<?> clazz,
                     Class<?>... paramTypes)

Determine whether the given class has a public constructor with the given signature.

Essentially translates NoSuchMethodException to "false".

Parameters:

clazz - the clazz to analyze

paramTypes - the parameter types of the method

Returns:

whether the class has a corresponding constructor

See Also:

Class.getMethod(java.lang.String, java.lang.Class<?>...)

getConstructorIfAvailable

public static <T> Constructor<T> getConstructorIfAvailable(Class<T> clazz,
                                           Class<?>... paramTypes)

Determine whether the given class has a public constructor with the given signature, and return it if available (else return null).

Essentially translates NoSuchMethodException to null.

Parameters:

clazz - the clazz to analyze

paramTypes - the parameter types of the method

Returns:

the constructor, or null if not found

See Also:

Class.getConstructor(java.lang.Class<?>...)

hasMethod

public static boolean hasMethod(Class<?> clazz,
                String methodName,
                Class<?>... paramTypes)

Determine whether the given class has a public method with the given signature.

Essentially translates NoSuchMethodException to "false".

Parameters:

clazz - the clazz to analyze

methodName - the name of the method

paramTypes - the parameter types of the method

Returns:

whether the class has a corresponding method

See Also:

Class.getMethod(java.lang.String, java.lang.Class<?>...)

getMethod

public static Method getMethod(Class<?> clazz,
               String methodName,
               Class<?>... paramTypes)

Determine whether the given class has a public method with the given signature, and return it if available (else throws an IllegalStateException).

In case of any signature specified, only returns the method if there is a unique candidate, i.e. a single public method with the specified name.

Essentially translates NoSuchMethodException to IllegalStateException.

Parameters:

clazz - the clazz to analyze

methodName - the name of the method

paramTypes - the parameter types of the method (may be null to indicate any signature)

Returns:

the method (never null)

Throws:

IllegalStateException - if the method has not been found

See Also:

Class.getMethod(java.lang.String, java.lang.Class<?>...)

getMethodIfAvailable

public static Method getMethodIfAvailable(Class<?> clazz,
                          String methodName,
                          Class<?>... paramTypes)

Determine whether the given class has a public method with the given signature, and return it if available (else return null).

In case of any signature specified, only returns the method if there is a unique candidate, i.e. a single public method with the specified name.

Essentially translates NoSuchMethodException to null.

Parameters:

clazz - the clazz to analyze

methodName - the name of the method

paramTypes - the parameter types of the method (may be null to indicate any signature)

Returns:

the method, or null if not found

See Also:

Class.getMethod(java.lang.String, java.lang.Class<?>...)

getMethodCountForName

public static int getMethodCountForName(Class<?> clazz,
                        String methodName)

Return the number of methods with a given name (with any argument types), for the given class and/or its superclasses. Includes non-public methods.

Parameters:

clazz - the clazz to check

methodName - the name of the method

Returns:

the number of methods with the given name

hasAtLeastOneMethodWithName

public static boolean hasAtLeastOneMethodWithName(Class<?> clazz,
                                  String methodName)

Does the given class or one of its superclasses at least have one or more methods with the supplied name (with any argument types)? Includes non-public methods.

Parameters:

clazz - the clazz to check

methodName - the name of the method

Returns:

whether there is at least one method with the given name

getMostSpecificMethod

public static Method getMostSpecificMethod(Method method,
                           Class<?> targetClass)

Given a method, which may come from an interface, and a target class used in the current reflective invocation, find the corresponding target method if there is one. E.g. the method may be IFoo.bar() and the target class may be DefaultFoo. In this case, the method may be DefaultFoo.bar(). This enables attributes on that method to be found.

NOTE: In contrast to AopUtils.getMostSpecificMethod(java.lang.reflect.Method, java.lang.Class<?>), this method does not resolve Java 5 bridge methods automatically. Call BridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method) if bridge method resolution is desirable (e.g. for obtaining metadata from the original method definition).

NOTE: Since Spring 3.1.1, if Java security settings disallow reflective access (e.g. calls to Class#getDeclaredMethods etc, this implementation will fall back to returning the originally provided method.

Parameters:

method - the method to be invoked, which may come from an interface

targetClass - the target class for the current invocation. May be null or may not even implement the method.

Returns:

the specific target method, or the original method if the targetClass doesn't implement it or is null

getStaticMethod

public static Method getStaticMethod(Class<?> clazz,
                     String methodName,
                     Class<?>... args)

Return a public static method of a class.

Parameters:

clazz - the class which defines the method

methodName - the static method name

args - the parameter types to the method

Returns:

the static method, or null if no static method was found

Throws:

IllegalArgumentException - if the method name is blank or the clazz is null

isPrimitiveWrapper

public static boolean isPrimitiveWrapper(Class<?> clazz)

Check if the given class represents a primitive wrapper, i.e. Boolean, Byte, Character, Short, Integer, Long, Float, or Double.

Parameters:

clazz - the class to check

Returns:

whether the given class is a primitive wrapper class

isPrimitiveOrWrapper

public static boolean isPrimitiveOrWrapper(Class<?> clazz)

Check if the given class represents a primitive (i.e. boolean, byte, char, short, int, long, float, or double) or a primitive wrapper (i.e. Boolean, Byte, Character, Short, Integer, Long, Float, or Double).

Parameters:

clazz - the class to check

Returns:

whether the given class is a primitive or primitive wrapper class

isPrimitiveArray

public static boolean isPrimitiveArray(Class<?> clazz)

Check if the given class represents an array of primitives, i.e. boolean, byte, char, short, int, long, float, or double.

Parameters:

clazz - the class to check

Returns:

whether the given class is a primitive array class

isPrimitiveWrapperArray

public static boolean isPrimitiveWrapperArray(Class<?> clazz)

Check if the given class represents an array of primitive wrappers, i.e. Boolean, Byte, Character, Short, Integer, Long, Float, or Double.

Parameters:

clazz - the class to check

Returns:

whether the given class is a primitive wrapper array class

resolvePrimitiveIfNecessary

public static Class<?> resolvePrimitiveIfNecessary(Class<?> clazz)

Resolve the given class if it is a primitive class, returning the corresponding primitive wrapper type instead.

Parameters:

clazz - the class to check

Returns:

the original class, or a primitive wrapper for the original primitive type

isAssignable

public static boolean isAssignable(Class<?> lhsType,
                   Class<?> rhsType)

Check if the right-hand side type may be assigned to the left-hand side type, assuming setting by reflection. Considers primitive wrapper classes as assignable to the corresponding primitive types.

Parameters:

lhsType - the target type

rhsType - the value type that should be assigned to the target type

Returns:

if the target type is assignable from the value type

See Also:

TypeUtils.isAssignable(java.lang.reflect.Type, java.lang.reflect.Type)

isAssignableValue

public static boolean isAssignableValue(Class<?> type,
                        Object value)

Determine if the given type is assignable from the given value, assuming setting by reflection. Considers primitive wrapper classes as assignable to the corresponding primitive types.

Parameters:

type - the target type

value - the value that should be assigned to the type

Returns:

if the type is assignable from the value

convertResourcePathToClassName

public static String convertResourcePathToClassName(String resourcePath)

Convert a "/"-based resource path to a "."-based fully qualified class name.

Parameters:

resourcePath - the resource path pointing to a class

Returns:

the corresponding fully qualified class name

convertClassNameToResourcePath

public static String convertClassNameToResourcePath(String className)

Convert a "."-based fully qualified class name to a "/"-based resource path.

Parameters:

className - the fully qualified class name

Returns:

the corresponding resource path, pointing to the class

addResourcePathToPackagePath

public static String addResourcePathToPackagePath(Class<?> clazz,
                                  String resourceName)

Return a path suitable for use with ClassLoader.getResource (also suitable for use with Class.getResource by prepending a slash ('/') to the return value). Built by taking the package of the specified class file, converting all dots ('.') to slashes ('/'), adding a trailing slash if necessary, and concatenating the specified resource name to this.
As such, this function may be used to build a path suitable for loading a resource file that is in the same package as a class file, although ClassPathResource is usually even more convenient.

Parameters:

clazz - the Class whose package will be used as the base

resourceName - the resource name to append. A leading slash is optional.

Returns:

the built-up resource path

See Also:

ClassLoader.getResource(java.lang.String), Class.getResource(java.lang.String)

classPackageAsResourcePath

public static String classPackageAsResourcePath(Class<?> clazz)

Given an input class object, return a string which consists of the class's package name as a pathname, i.e., all dots ('.') are replaced by slashes ('/'). Neither a leading nor trailing slash is added. The result could be concatenated with a slash and the name of a resource and fed directly to ClassLoader.getResource(). For it to be fed to Class.getResource instead, a leading slash would also have to be prepended to the returned value.

Parameters:

clazz - the input class. A null value or the default (empty) package will result in an empty string ("") being returned.

Returns:

a path which represents the package name

See Also:

ClassLoader.getResource(java.lang.String), Class.getResource(java.lang.String)

classNamesToString

public static String classNamesToString(Class... classes)

Build a String that consists of the names of the classes/interfaces in the given array.

Basically like AbstractCollection.toString(), but stripping the "class "/"interface " prefix before every class name.

Parameters:

classes - a Collection of Class objects (may be null)

Returns:

a String of form "[com.foo.Bar, com.foo.Baz]"

See Also:

AbstractCollection.toString()

classNamesToString

public static String classNamesToString(Collection<Class> classes)

Build a String that consists of the names of the classes/interfaces in the given collection.

Basically like AbstractCollection.toString(), but stripping the "class "/"interface " prefix before every class name.

Parameters:

classes - a Collection of Class objects (may be null)

Returns:

a String of form "[com.foo.Bar, com.foo.Baz]"

See Also:

AbstractCollection.toString()

toClassArray

public static Class<?>[] toClassArray(Collection<Class<?>> collection)

Copy the given Collection into a Class array. The Collection must contain Class elements only.

Parameters:

collection - the Collection to copy

Returns:

the Class array (null if the passed-in Collection was null)

getAllInterfaces

public static Class<?>[] getAllInterfaces(Object instance)

Return all interfaces that the given instance implements as array, including ones implemented by superclasses.

Parameters:

instance - the instance to analyze for interfaces

Returns:

all interfaces that the given instance implements as array

getAllInterfacesForClass

public static Class<?>[] getAllInterfacesForClass(Class<?> clazz)

Return all interfaces that the given class implements as array, including ones implemented by superclasses.

If the class itself is an interface, it gets returned as sole interface.

Parameters:

clazz - the class to analyze for interfaces

Returns:

all interfaces that the given object implements as array

getAllInterfacesForClass

public static Class<?>[] getAllInterfacesForClass(Class<?> clazz,
                                  ClassLoader classLoader)

Return all interfaces that the given class implements as array, including ones implemented by superclasses.

If the class itself is an interface, it gets returned as sole interface.

Parameters:

clazz - the class to analyze for interfaces

classLoader - the ClassLoader that the interfaces need to be visible in (may be null when accepting all declared interfaces)

Returns:

all interfaces that the given object implements as array

getAllInterfacesAsSet

public static Set<Class> getAllInterfacesAsSet(Object instance)

Return all interfaces that the given instance implements as Set, including ones implemented by superclasses.

Parameters:

instance - the instance to analyze for interfaces

Returns:

all interfaces that the given instance implements as Set

getAllInterfacesForClassAsSet

public static Set<Class> getAllInterfacesForClassAsSet(Class clazz)

Return all interfaces that the given class implements as Set, including ones implemented by superclasses.

If the class itself is an interface, it gets returned as sole interface.

Parameters:

clazz - the class to analyze for interfaces

Returns:

all interfaces that the given object implements as Set

getAllInterfacesForClassAsSet

public static Set<Class> getAllInterfacesForClassAsSet(Class clazz,
                                       ClassLoader classLoader)

Return all interfaces that the given class implements as Set, including ones implemented by superclasses.

If the class itself is an interface, it gets returned as sole interface.

Parameters:

clazz - the class to analyze for interfaces

classLoader - the ClassLoader that the interfaces need to be visible in (may be null when accepting all declared interfaces)

Returns:

all interfaces that the given object implements as Set

createCompositeInterface

public static Class<?> createCompositeInterface(Class<?>[] interfaces,
                                ClassLoader classLoader)

Create a composite interface Class for the given interfaces, implementing the given interfaces in one single Class.

This implementation builds a JDK proxy class for the given interfaces.

Parameters:

interfaces - the interfaces to merge

classLoader - the ClassLoader to create the composite Class in

Returns:

the merged interface as Class

See Also:

Proxy.getProxyClass(java.lang.ClassLoader, java.lang.Class<?>...)

determineCommonAncestor

public static Class<?> determineCommonAncestor(Class<?> clazz1,
                               Class<?> clazz2)

Determine the common ancestor of the given classes, if any.

Parameters:

clazz1 - the class to introspect

clazz2 - the other class to introspect

Returns:

the common ancestor (i.e. common superclass, one interface extending the other), or null if none found. If any of the given classes is null, the other class will be returned.

Since:

3.2.6

isVisible

public static boolean isVisible(Class<?> clazz,
                ClassLoader classLoader)

Check whether the given class is visible in the given ClassLoader.

Parameters:

clazz - the class to check (typically an interface)

classLoader - the ClassLoader to check against (may be null, in which case this method will always return true)

isCglibProxy

public static boolean isCglibProxy(Object object)

Check whether the given object is a CGLIB proxy.

Parameters:

object - the object to check

See Also:

AopUtils.isCglibProxy(Object)

isCglibProxyClass

public static boolean isCglibProxyClass(Class<?> clazz)

Check whether the specified class is a CGLIB-generated class.

Parameters:

clazz - the class to check

isCglibProxyClassName

public static boolean isCglibProxyClassName(String className)

Check whether the specified class name is a CGLIB-generated class.

Parameters:

className - the class name to check