Package org.apache.commons.lang3

Class ClassUtils

java.lang.Object

org.apache.commons.lang3.ClassUtils

public class ClassUtils
extends java.lang.Object

Operates on classes without using reflection.

This class handles invalid null inputs as best it can. Each method documents its behaviour in more detail.

The notion of a canonical name includes the human readable name for the type, for example int[]. The non-canonical method variants work with the JVM names, such as [I.

Since:

2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ClassUtils.Interfaces	Inclusivity literals for hierarchy(Class, Interfaces).

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	INNER_CLASS_SEPARATOR	The inner class separator String: "$".
static char	INNER_CLASS_SEPARATOR_CHAR	The inner class separator character: '$' == 36.
static java.lang.String	PACKAGE_SEPARATOR	The package separator String: ".".
static char	PACKAGE_SEPARATOR_CHAR	The package separator character: '.' == 46.

Constructor Summary

Constructors

Constructor	Description
ClassUtils()	ClassUtils instances should NOT be constructed in standard programming.

Method Summary

Modifier and Type	Method	Description
static java.util.List<java.lang.String>	convertClassesToClassNames(java.util.List<java.lang.Class<?>> classes)	Given a List of Class objects, this method converts them into class names.
static java.util.List<java.lang.Class<?>>	convertClassNamesToClasses(java.util.List<java.lang.String> classNames)	Given a List of class names, this method converts them into classes.
static java.lang.String	getAbbreviatedName(java.lang.Class<?> cls, int len)	Gets the abbreviated name of a Class.
static java.lang.String	getAbbreviatedName(java.lang.String className, int len)	Gets the abbreviated class name from a String.
static java.util.List<java.lang.Class<?>>	getAllInterfaces(java.lang.Class<?> cls)	Gets a List of all interfaces implemented by the given class and its superclasses.
static java.util.List<java.lang.Class<?>>	getAllSuperclasses(java.lang.Class<?> cls)	Gets a List of superclasses for the given class.
static java.lang.String	getCanonicalName(java.lang.Class<?> cls)	Gets the canonical class name for a Class.
static java.lang.String	getCanonicalName(java.lang.Class<?> cls, java.lang.String valueIfNull)	Gets the canonical name for a Class.
static java.lang.String	getCanonicalName(java.lang.Object object)	Gets the canonical name for an Object.
static java.lang.String	getCanonicalName(java.lang.Object object, java.lang.String valueIfNull)	Gets the canonical name for an Object.
static java.lang.Class<?>	getClass(java.lang.ClassLoader classLoader, java.lang.String className)	Returns the (initialized) class represented by className using the classLoader.
static java.lang.Class<?>	getClass(java.lang.ClassLoader classLoader, java.lang.String className, boolean initialize)	Returns the class represented by className using the classLoader.
static java.lang.Class<?>	getClass(java.lang.String className)	Returns the (initialized) class represented by className using the current thread's context class loader.
static java.lang.Class<?>	getClass(java.lang.String className, boolean initialize)	Returns the class represented by className using the current thread's context class loader.
static java.lang.String	getName(java.lang.Class<?> cls)	Null-safe version of Class.getName()
static java.lang.String	getName(java.lang.Class<?> cls, java.lang.String valueIfNull)	Null-safe version of aClass.getName()
static java.lang.String	getName(java.lang.Object object)	Null-safe version of Class.getName()
static java.lang.String	getName(java.lang.Object object, java.lang.String valueIfNull)	Null-safe version of aClass.getSimpleName()
static java.lang.String	getPackageCanonicalName(java.lang.Class<?> cls)	Gets the package name from the canonical name of a Class.
static java.lang.String	getPackageCanonicalName(java.lang.Object object, java.lang.String valueIfNull)	Gets the package name from the canonical name of an Object.
static java.lang.String	getPackageCanonicalName(java.lang.String canonicalName)	Gets the package name from the canonical name.
static java.lang.String	getPackageName(java.lang.Class<?> cls)	Gets the package name of a Class.
static java.lang.String	getPackageName(java.lang.Object object, java.lang.String valueIfNull)	Gets the package name of an Object.
static java.lang.String	getPackageName(java.lang.String className)	Gets the package name from a String.
static java.lang.reflect.Method	getPublicMethod(java.lang.Class<?> cls, java.lang.String methodName, java.lang.Class<?>... parameterTypes)	Returns the desired Method much like Class.getMethod, however it ensures that the returned Method is from a public class or interface and not from an anonymous inner class.
static java.lang.String	getShortCanonicalName(java.lang.Class<?> cls)	Gets the canonical name minus the package name from a Class.
static java.lang.String	getShortCanonicalName(java.lang.Object object, java.lang.String valueIfNull)	Gets the canonical name minus the package name for an Object.
static java.lang.String	getShortCanonicalName(java.lang.String canonicalName)	Gets the canonical name minus the package name from a String.
static java.lang.String	getShortClassName(java.lang.Class<?> cls)	Gets the class name minus the package name from a Class.
static java.lang.String	getShortClassName(java.lang.Object object, java.lang.String valueIfNull)	Gets the class name minus the package name for an Object.
static java.lang.String	getShortClassName(java.lang.String className)	Gets the class name minus the package name from a String.
static java.lang.String	getSimpleName(java.lang.Class<?> cls)	Null-safe version of aClass.getSimpleName()
static java.lang.String	getSimpleName(java.lang.Class<?> cls, java.lang.String valueIfNull)	Null-safe version of aClass.getSimpleName()
static java.lang.String	getSimpleName(java.lang.Object object)	Null-safe version of aClass.getSimpleName()
static java.lang.String	getSimpleName(java.lang.Object object, java.lang.String valueIfNull)	Null-safe version of aClass.getSimpleName()
static java.lang.Iterable<java.lang.Class<?>>	hierarchy(java.lang.Class<?> type)	Get an Iterable that can iterate over a class hierarchy in ascending (subclass to superclass) order, excluding interfaces.
static java.lang.Iterable<java.lang.Class<?>>	hierarchy(java.lang.Class<?> type, ClassUtils.Interfaces interfacesBehavior)	Get an Iterable that can iterate over a class hierarchy in ascending (subclass to superclass) order.
static boolean	isAssignable(java.lang.Class<?>[] classArray, java.lang.Class<?>... toClassArray)	Checks if an array of Classes can be assigned to another array of Classes.
static boolean	isAssignable(java.lang.Class<?>[] classArray, java.lang.Class<?>[] toClassArray, boolean autoboxing)	Checks if an array of Classes can be assigned to another array of Classes.
static boolean	isAssignable(java.lang.Class<?> cls, java.lang.Class<?> toClass)	Checks if one Class can be assigned to a variable of another Class.
static boolean	isAssignable(java.lang.Class<?> cls, java.lang.Class<?> toClass, boolean autoboxing)	Checks if one Class can be assigned to a variable of another Class.
static boolean	isInnerClass(java.lang.Class<?> cls)	Is the specified class an inner class or static nested class.
static boolean	isPrimitiveOrWrapper(java.lang.Class<?> type)	Returns whether the given type is a primitive or primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).
static boolean	isPrimitiveWrapper(java.lang.Class<?> type)	Returns whether the given type is a primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).
static java.lang.Class<?>[]	primitivesToWrappers(java.lang.Class<?>... classes)	Converts the specified array of primitive Class objects to an array of its corresponding wrapper Class objects.
static java.lang.Class<?>	primitiveToWrapper(java.lang.Class<?> cls)	Converts the specified primitive Class object to its corresponding wrapper Class object.
static java.lang.Class<?>[]	toClass(java.lang.Object... array)	Converts an array of Object in to an array of Class objects.
static java.lang.Class<?>[]	wrappersToPrimitives(java.lang.Class<?>... classes)	Converts the specified array of wrapper Class objects to an array of its corresponding primitive Class objects.
static java.lang.Class<?>	wrapperToPrimitive(java.lang.Class<?> cls)	Converts the specified wrapper class to its corresponding primitive class.

Methods inherited from class java.lang.Object

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

Field Detail

PACKAGE_SEPARATOR_CHAR

public static final char PACKAGE_SEPARATOR_CHAR

The package separator character: '.' == 46.

See Also:

Constant Field Values

PACKAGE_SEPARATOR

public static final java.lang.String PACKAGE_SEPARATOR

The package separator String: ".".

INNER_CLASS_SEPARATOR_CHAR

public static final char INNER_CLASS_SEPARATOR_CHAR

The inner class separator character: '$' == 36.

See Also:

Constant Field Values

INNER_CLASS_SEPARATOR

public static final java.lang.String INNER_CLASS_SEPARATOR

The inner class separator String: "$".

Constructor Detail

ClassUtils

public ClassUtils()

ClassUtils instances should NOT be constructed in standard programming. Instead, the class should be used as ClassUtils.getShortClassName(cls).

This constructor is public to permit tools that require a JavaBean instance to operate.

Method Detail

getShortClassName

public static java.lang.String getShortClassName(java.lang.Object object,
                                                 java.lang.String valueIfNull)

Gets the class name minus the package name for an Object.

Parameters:

object - the class to get the short name for, may be null

valueIfNull - the value to return if null

Returns:

the class name of the object without the package name, or the null value

getShortClassName

public static java.lang.String getShortClassName(java.lang.Class<?> cls)

Gets the class name minus the package name from a Class.

Consider using the Java 5 API Class.getSimpleName() instead. The one known difference is that this code will return "Map.Entry" while the java.lang.Class variant will simply return "Entry".

Parameters:

cls - the class to get the short name for.

Returns:

the class name without the package name or an empty string

getShortClassName

public static java.lang.String getShortClassName(java.lang.String className)

Gets the class name minus the package name from a String.

The string passed in is assumed to be a class name - it is not checked.

Note that this method differs from Class.getSimpleName() in that this will return "Map.Entry" whilst the java.lang.Class variant will simply return "Entry".

Parameters:

className - the className to get the short name for

Returns:

the class name of the class without the package name or an empty string

getSimpleName

public static java.lang.String getSimpleName(java.lang.Class<?> cls)

Null-safe version of aClass.getSimpleName()

Parameters:

cls - the class for which to get the simple name; may be null

Returns:

the simple class name.

Since:

3.0

See Also:

Class.getSimpleName()

getSimpleName

public static java.lang.String getSimpleName(java.lang.Class<?> cls,
                                             java.lang.String valueIfNull)

Null-safe version of aClass.getSimpleName()

Parameters:

cls - the class for which to get the simple name; may be null

valueIfNull - the value to return if null

Returns:

the simple class name or valueIfNull

Since:

3.0

See Also:

Class.getSimpleName()

getSimpleName

public static java.lang.String getSimpleName(java.lang.Object object)

Null-safe version of aClass.getSimpleName()

Parameters:

object - the object for which to get the simple class name; may be null

Returns:

the simple class name or the empty String

Since:

3.7

See Also:

Class.getSimpleName()

getSimpleName

public static java.lang.String getSimpleName(java.lang.Object object,
                                             java.lang.String valueIfNull)

Null-safe version of aClass.getSimpleName()

Parameters:

object - the object for which to get the simple class name; may be null

valueIfNull - the value to return if object is null

Returns:

the simple class name or valueIfNull

Since:

3.0

See Also:

Class.getSimpleName()

getName

public static java.lang.String getName(java.lang.Class<?> cls)

Null-safe version of Class.getName()

Parameters:

cls - the class for which to get the class name; may be null

Returns:

the class name or the empty String.

Since:

3.7

See Also:

Class.getSimpleName()

getName

public static java.lang.String getName(java.lang.Class<?> cls,
                                       java.lang.String valueIfNull)

Null-safe version of aClass.getName()

Parameters:

cls - the class for which to get the class name; may be null

valueIfNull - the return value if cls is null

Returns:

the class name or valueIfNull

Since:

3.7

See Also:

Class.getName()

getName

public static java.lang.String getName(java.lang.Object object)

Null-safe version of Class.getName()

Parameters:

object - the object for which to get the class name; may be null

Returns:

the class name or the empty String

Since:

3.7

See Also:

Class.getSimpleName()

getName

public static java.lang.String getName(java.lang.Object object,
                                       java.lang.String valueIfNull)

Null-safe version of aClass.getSimpleName()

Parameters:

object - the object for which to get the class name; may be null

valueIfNull - the value to return if object is null

Returns:

the class name or valueIfNull

Since:

3.0

See Also:

Class.getName()

getPackageName

public static java.lang.String getPackageName(java.lang.Object object,
                                              java.lang.String valueIfNull)

Gets the package name of an Object.

Parameters:

object - the class to get the package name for, may be null

valueIfNull - the value to return if null

Returns:

the package name of the object, or the null value

getPackageName

public static java.lang.String getPackageName(java.lang.Class<?> cls)

Gets the package name of a Class.

Parameters:

cls - the class to get the package name for, may be null.

Returns:

the package name or an empty string

getPackageName

public static java.lang.String getPackageName(java.lang.String className)

Gets the package name from a String.

The string passed in is assumed to be a class name - it is not checked.

If the class is unpackaged, return an empty string.

Parameters:

className - the className to get the package name for, may be null

Returns:

the package name or an empty string

getAbbreviatedName

public static java.lang.String getAbbreviatedName(java.lang.Class<?> cls,
                                                  int len)

Gets the abbreviated name of a Class.

Parameters:

cls - the class to get the abbreviated name for, may be null

len - the desired length of the abbreviated name

Returns:

the abbreviated name or an empty string

Throws:

java.lang.IllegalArgumentException - if len <= 0

Since:

3.4

See Also:

getAbbreviatedName(String, int)

getAbbreviatedName

public static java.lang.String getAbbreviatedName(java.lang.String className,
                                                  int len)

Gets the abbreviated class name from a String.

The string passed in is assumed to be a class name - it is not checked.

The abbreviation algorithm will shorten the class name, usually without significant loss of meaning.

The abbreviated class name will always include the complete package hierarchy. If enough space is available, rightmost sub-packages will be displayed in full length.

Examples

className	len	return
null	1	""
"java.lang.String"	5	"j.l.String"
"java.lang.String"	15	"j.lang.String"
"java.lang.String"	30	"java.lang.String"

Parameters:

className - the className to get the abbreviated name for, may be null

len - the desired length of the abbreviated name

Returns:

the abbreviated name or an empty string

Throws:

java.lang.IllegalArgumentException - if len <= 0

Since:

3.4

getAllSuperclasses

public static java.util.List<java.lang.Class<?>> getAllSuperclasses(java.lang.Class<?> cls)

Gets a List of superclasses for the given class.

Parameters:

cls - the class to look up, may be null

Returns:

the List of superclasses in order going up from this one null if null input

getAllInterfaces

public static java.util.List<java.lang.Class<?>> getAllInterfaces(java.lang.Class<?> cls)

Gets a List of all interfaces implemented by the given class and its superclasses.

The order is determined by looking through each interface in turn as declared in the source file and following its hierarchy up. Then each superclass is considered in the same way. Later duplicates are ignored, so the order is maintained.

Parameters:

cls - the class to look up, may be null

Returns:

the List of interfaces in order, null if null input

convertClassNamesToClasses

public static java.util.List<java.lang.Class<?>> convertClassNamesToClasses(java.util.List<java.lang.String> classNames)

Given a List of class names, this method converts them into classes.

A new List is returned. If the class name cannot be found, null is stored in the List. If the class name in the List is null, null is stored in the output List.

Parameters:

classNames - the classNames to change

Returns:

a List of Class objects corresponding to the class names, null if null input

Throws:

java.lang.ClassCastException - if classNames contains a non String entry

convertClassesToClassNames

public static java.util.List<java.lang.String> convertClassesToClassNames(java.util.List<java.lang.Class<?>> classes)

Given a List of Class objects, this method converts them into class names.

A new List is returned. null objects will be copied into the returned list as null.

Parameters:

classes - the classes to change

Returns:

a List of class names corresponding to the Class objects, null if null input

Throws:

java.lang.ClassCastException - if classes contains a non-Class entry

isAssignable

public static boolean isAssignable(java.lang.Class<?>[] classArray,
                                   java.lang.Class<?>... toClassArray)

Checks if an array of Classes can be assigned to another array of Classes.

This method calls isAssignable for each Class pair in the input arrays. It can be used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter types (the second parameter).

Unlike the Class.isAssignableFrom(java.lang.Class) method, this method takes into account widenings of primitive classes and nulls.

Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result for these cases.

Null may be assigned to any reference type. This method will return true if null is passed in and the toClass is non-primitive.

Specifically, this method tests whether the type represented by the specified Class parameter can be converted to the type represented by this Class object via an identity conversion widening primitive or widening reference conversion. See The Java Language Specification, sections 5.1.1, 5.1.2 and 5.1.4 for details.

Since Lang 3.0, this method will default behavior for calculating assignability between primitive and wrapper types corresponding to the running Java version; i.e. autoboxing will be the default behavior in VMs running Java versions > 1.5.

Parameters:

classArray - the array of Classes to check, may be null

toClassArray - the array of Classes to try to assign into, may be null

Returns:

true if assignment possible

isAssignable

public static boolean isAssignable(java.lang.Class<?>[] classArray,
                                   java.lang.Class<?>[] toClassArray,
                                   boolean autoboxing)

Checks if an array of Classes can be assigned to another array of Classes.

This method calls isAssignable for each Class pair in the input arrays. It can be used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter types (the second parameter).

Unlike the Class.isAssignableFrom(java.lang.Class) method, this method takes into account widenings of primitive classes and nulls.

Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result for these cases.

Null may be assigned to any reference type. This method will return true if null is passed in and the toClass is non-primitive.

Specifically, this method tests whether the type represented by the specified Class parameter can be converted to the type represented by this Class object via an identity conversion widening primitive or widening reference conversion. See The Java Language Specification, sections 5.1.1, 5.1.2 and 5.1.4 for details.

Parameters:

classArray - the array of Classes to check, may be null

toClassArray - the array of Classes to try to assign into, may be null

autoboxing - whether to use implicit autoboxing/unboxing between primitives and wrappers

Returns:

true if assignment possible

isPrimitiveOrWrapper

public static boolean isPrimitiveOrWrapper(java.lang.Class<?> type)

Returns whether the given type is a primitive or primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).

Parameters:

type - The class to query or null.

Returns:

true if the given type is a primitive or primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).

Since:

3.1

isPrimitiveWrapper

public static boolean isPrimitiveWrapper(java.lang.Class<?> type)

Returns whether the given type is a primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).

Parameters:

type - The class to query or null.

Returns:

true if the given type is a primitive wrapper (Boolean, Byte, Character, Short, Integer, Long, Double, Float).

Since:

3.1

isAssignable

public static boolean isAssignable(java.lang.Class<?> cls,
                                   java.lang.Class<?> toClass)

Checks if one Class can be assigned to a variable of another Class.

Unlike the Class.isAssignableFrom(java.lang.Class) method, this method takes into account widenings of primitive classes and nulls.

Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result for these cases.

Null may be assigned to any reference type. This method will return true if null is passed in and the toClass is non-primitive.

Specifically, this method tests whether the type represented by the specified Class parameter can be converted to the type represented by this Class object via an identity conversion widening primitive or widening reference conversion. See The Java Language Specification, sections 5.1.1, 5.1.2 and 5.1.4 for details.

Since Lang 3.0, this method will default behavior for calculating assignability between primitive and wrapper types corresponding to the running Java version; i.e. autoboxing will be the default behavior in VMs running Java versions > 1.5.

Parameters:

cls - the Class to check, may be null

toClass - the Class to try to assign into, returns false if null

Returns:

true if assignment possible

isAssignable

public static boolean isAssignable(java.lang.Class<?> cls,
                                   java.lang.Class<?> toClass,
                                   boolean autoboxing)

Checks if one Class can be assigned to a variable of another Class.

Unlike the Class.isAssignableFrom(java.lang.Class) method, this method takes into account widenings of primitive classes and nulls.

Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result for these cases.

Null may be assigned to any reference type. This method will return true if null is passed in and the toClass is non-primitive.

Specifically, this method tests whether the type represented by the specified Class parameter can be converted to the type represented by this Class object via an identity conversion widening primitive or widening reference conversion. See The Java Language Specification, sections 5.1.1, 5.1.2 and 5.1.4 for details.

Parameters:

cls - the Class to check, may be null

toClass - the Class to try to assign into, returns false if null

autoboxing - whether to use implicit autoboxing/unboxing between primitives and wrappers

Returns:

true if assignment possible

primitiveToWrapper

public static java.lang.Class<?> primitiveToWrapper(java.lang.Class<?> cls)

Converts the specified primitive Class object to its corresponding wrapper Class object.

NOTE: From v2.2, this method handles Void.TYPE, returning Void.TYPE.

Parameters:

cls - the class to convert, may be null

Returns:

the wrapper class for cls or cls if cls is not a primitive. null if null input.

Since:

2.1

primitivesToWrappers

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

Converts the specified array of primitive Class objects to an array of its corresponding wrapper Class objects.

Parameters:

classes - the class array to convert, may be null or empty

Returns:

an array which contains for each given class, the wrapper class or the original class if class is not a primitive. null if null input. Empty array if an empty array passed in.

Since:

2.1

wrapperToPrimitive

public static java.lang.Class<?> wrapperToPrimitive(java.lang.Class<?> cls)

Converts the specified wrapper class to its corresponding primitive class.

This method is the counter part of primitiveToWrapper(). If the passed in class is a wrapper class for a primitive type, this primitive type will be returned (e.g. Integer.TYPE for Integer.class). For other classes, or if the parameter is null, the return value is null.

Parameters:

cls - the class to convert, may be null

Returns:

the corresponding primitive type if cls is a wrapper class, null otherwise

Since:

2.4

See Also:

primitiveToWrapper(Class)

wrappersToPrimitives

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

Converts the specified array of wrapper Class objects to an array of its corresponding primitive Class objects.

This method invokes wrapperToPrimitive() for each element of the passed in array.

Parameters:

classes - the class array to convert, may be null or empty

Returns:

an array which contains for each given class, the primitive class or null if the original class is not a wrapper class. null if null input. Empty array if an empty array passed in.

Since:

2.4

See Also:

wrapperToPrimitive(Class)

isInnerClass

public static boolean isInnerClass(java.lang.Class<?> cls)

Is the specified class an inner class or static nested class.

Parameters:

cls - the class to check, may be null

Returns:

true if the class is an inner or static nested class, false if not or null

getClass

public static java.lang.Class<?> getClass(java.lang.ClassLoader classLoader,
                                          java.lang.String className,
                                          boolean initialize)
                                   throws java.lang.ClassNotFoundException

Returns the class represented by className using the classLoader. This implementation supports the syntaxes "java.util.Map.Entry[]", "java.util.Map$Entry[]", "[Ljava.util.Map.Entry;", and "[Ljava.util.Map$Entry;".

Parameters:

classLoader - the class loader to use to load the class

className - the class name

initialize - whether the class must be initialized

Returns:

the class represented by className using the classLoader

Throws:

java.lang.ClassNotFoundException - if the class is not found

getClass

public static java.lang.Class<?> getClass(java.lang.ClassLoader classLoader,
                                          java.lang.String className)
                                   throws java.lang.ClassNotFoundException

Returns the (initialized) class represented by className using the classLoader. This implementation supports the syntaxes "java.util.Map.Entry[]", "java.util.Map$Entry[]", "[Ljava.util.Map.Entry;", and "[Ljava.util.Map$Entry;".

Parameters:

classLoader - the class loader to use to load the class

className - the class name

Returns:

the class represented by className using the classLoader

Throws:

java.lang.ClassNotFoundException - if the class is not found

getClass

public static java.lang.Class<?> getClass(java.lang.String className)
                                   throws java.lang.ClassNotFoundException

Returns the (initialized) class represented by className using the current thread's context class loader. This implementation supports the syntaxes "java.util.Map.Entry[]", "java.util.Map$Entry[]", "[Ljava.util.Map.Entry;", and "[Ljava.util.Map$Entry;".

Parameters:

className - the class name

Returns:

the class represented by className using the current thread's context class loader

Throws:

java.lang.ClassNotFoundException - if the class is not found

getClass

public static java.lang.Class<?> getClass(java.lang.String className,
                                          boolean initialize)
                                   throws java.lang.ClassNotFoundException

Returns the class represented by className using the current thread's context class loader. This implementation supports the syntaxes "java.util.Map.Entry[]", "java.util.Map$Entry[]", "[Ljava.util.Map.Entry;", and "[Ljava.util.Map$Entry;".

Parameters:

className - the class name

initialize - whether the class must be initialized

Returns:

the class represented by className using the current thread's context class loader

Throws:

java.lang.ClassNotFoundException - if the class is not found

getPublicMethod

public static java.lang.reflect.Method getPublicMethod(java.lang.Class<?> cls,
                                                       java.lang.String methodName,
                                                       java.lang.Class<?>... parameterTypes)
                                                throws java.lang.NoSuchMethodException

Returns the desired Method much like Class.getMethod, however it ensures that the returned Method is from a public class or interface and not from an anonymous inner class. This means that the Method is invokable and doesn't fall foul of Java bug 4071957).

  Set set = Collections.unmodifiableSet(...);
  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);
  Object result = method.invoke(set, new Object[]);
  

Parameters:

cls - the class to check, not null

methodName - the name of the method

parameterTypes - the list of parameters

Returns:

the method

Throws:

java.lang.NullPointerException - if the class is null

java.lang.SecurityException - if a security violation occurred

java.lang.NoSuchMethodException - if the method is not found in the given class or if the method doesn't conform with the requirements

toClass

public static java.lang.Class<?>[] toClass(java.lang.Object... array)

Converts an array of Object in to an array of Class objects. If any of these objects is null, a null element will be inserted into the array.

This method returns null for a null input array.

Parameters:

array - an Object array

Returns:

a Class array, null if null array input

Since:

2.4

getShortCanonicalName

public static java.lang.String getShortCanonicalName(java.lang.Object object,
                                                     java.lang.String valueIfNull)

Gets the canonical name minus the package name for an Object.

Parameters:

object - the class to get the short name for, may be null

valueIfNull - the value to return if null

Returns:

the canonical name of the object without the package name, or the null value

Since:

2.4

getCanonicalName

public static java.lang.String getCanonicalName(java.lang.Class<?> cls)

Gets the canonical class name for a Class.

Parameters:

cls - the class for which to get the canonical class name; may be null

Returns:

the canonical name of the class, or the empty String

Since:

3.7

See Also:

Class.getCanonicalName()

getCanonicalName

public static java.lang.String getCanonicalName(java.lang.Class<?> cls,
                                                java.lang.String valueIfNull)

Gets the canonical name for a Class.

Parameters:

cls - the class for which to get the canonical class name; may be null

valueIfNull - the return value if null

Returns:

the canonical name of the class, or valueIfNull

Since:

3.7

See Also:

Class.getCanonicalName()

getCanonicalName

public static java.lang.String getCanonicalName(java.lang.Object object)

Gets the canonical name for an Object.

Parameters:

object - the object for which to get the canonical class name; may be null

Returns:

the canonical name of the object, or the empty String

Since:

3.7

See Also:

Class.getCanonicalName()

getCanonicalName

public static java.lang.String getCanonicalName(java.lang.Object object,
                                                java.lang.String valueIfNull)

Gets the canonical name for an Object.

Parameters:

object - the object for which to get the canonical class name; may be null

valueIfNull - the return value if null

Returns:

the canonical name of the object or valueIfNull

Since:

3.7

See Also:

Class.getCanonicalName()

getShortCanonicalName

public static java.lang.String getShortCanonicalName(java.lang.Class<?> cls)

Gets the canonical name minus the package name from a Class.

Parameters:

cls - the class for which to get the short canonical class name; may be null

Returns:

the canonical name without the package name or an empty string

Since:

2.4

getShortCanonicalName

public static java.lang.String getShortCanonicalName(java.lang.String canonicalName)

Gets the canonical name minus the package name from a String.

The string passed in is assumed to be a canonical name - it is not checked.

Parameters:

canonicalName - the class name to get the short name for

Returns:

the canonical name of the class without the package name or an empty string

Since:

2.4

getPackageCanonicalName

public static java.lang.String getPackageCanonicalName(java.lang.Object object,
                                                       java.lang.String valueIfNull)

Gets the package name from the canonical name of an Object.

Parameters:

object - the class to get the package name for, may be null

valueIfNull - the value to return if null

Returns:

the package name of the object, or the null value

Since:

2.4

getPackageCanonicalName

public static java.lang.String getPackageCanonicalName(java.lang.Class<?> cls)

Gets the package name from the canonical name of a Class.

Parameters:

cls - the class to get the package name for, may be null.

Returns:

the package name or an empty string

Since:

2.4

getPackageCanonicalName

public static java.lang.String getPackageCanonicalName(java.lang.String canonicalName)

Gets the package name from the canonical name.

The string passed in is assumed to be a canonical name - it is not checked.

If the class is unpackaged, return an empty string.

Parameters:

canonicalName - the canonical name to get the package name for, may be null

Returns:

the package name or an empty string

Since:

2.4

hierarchy

public static java.lang.Iterable<java.lang.Class<?>> hierarchy(java.lang.Class<?> type)

Get an Iterable that can iterate over a class hierarchy in ascending (subclass to superclass) order, excluding interfaces.

Parameters:

type - the type to get the class hierarchy from

Returns:

Iterable an Iterable over the class hierarchy of the given class

Since:

3.2

hierarchy

public static java.lang.Iterable<java.lang.Class<?>> hierarchy(java.lang.Class<?> type,
                                                               ClassUtils.Interfaces interfacesBehavior)

Get an Iterable that can iterate over a class hierarchy in ascending (subclass to superclass) order.

Parameters:

type - the type to get the class hierarchy from

interfacesBehavior - switch indicating whether to include or exclude interfaces

Returns:

Iterable an Iterable over the class hierarchy of the given class

Since:

3.2