Class ClassUtils
java.lang.Class
utility methods.
Mainly for internal use within the framework.- Since:
- 1.1
- Author:
- Juergen Hoeller, Keith Donald, Rob Harrop, Sam Brannen
- See Also:
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Field Summary
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionstatic String
addResourcePathToPackagePath
(Class<?> clazz, String resourceName) Return a path suitable for use withClassLoader.getResource
(also suitable for use withClass.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, ClassLoader classLoader) Replacement forClass.forName()
that also returns Class instances for primitives (e.g.static Class<?>[]
getAllInterfaces
(Object instance) Return all interfaces that the given instance implements as an array, including ones implemented by superclasses.getAllInterfacesAsSet
(Object instance) Return all interfaces that the given instance implements as a Set, including ones implemented by superclasses.static Class<?>[]
getAllInterfacesForClass
(Class<?> clazz) Return all interfaces that the given class implements as an array, including ones implemented by superclasses.static Class<?>[]
getAllInterfacesForClass
(Class<?> clazz, ClassLoader classLoader) Return all interfaces that the given class implements as an array, including ones implemented by superclasses.getAllInterfacesForClassAsSet
(Class<?> clazz) Return all interfaces that the given class implements as a Set, including ones implemented by superclasses.getAllInterfacesForClassAsSet
(Class<?> clazz, ClassLoader classLoader) Return all interfaces that the given class implements as a 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 returnnull
).static ClassLoader
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
getInterfaceMethodIfPossible
(Method method) Deprecated.static Method
getInterfaceMethodIfPossible
(Method method, Class<?> targetClass) Determine a corresponding interface method for the given method handle, if possible.static Method
Determine whether the given class has a public method with the given signature, and return it if available (else throws anIllegalStateException
).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 returnnull
).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 — for example, the method may beIFoo.bar()
, and the target class may beDefaultFoo
.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
getQualifiedMethodName
(Method method, Class<?> clazz) 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
Determine whether the given class has a public method with the given signature.static boolean
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) Deprecated.as of 5.2, in favor of custom (possibly narrower) checks such as for a Spring AOP proxystatic boolean
isCglibProxyClass
(Class<?> clazz) Deprecated.as of 5.2, in favor of custom (possibly narrower) checks or simply a check for containingCGLIB_CLASS_SEPARATOR
static boolean
isCglibProxyClassName
(String className) Deprecated.as of 5.2, in favor of custom (possibly narrower) checks or simply a check for containingCGLIB_CLASS_SEPARATOR
static boolean
isInnerClass
(Class<?> clazz) Determine if the supplied class is an inner class, i.e.static boolean
isJavaLanguageInterface
(Class<?> ifc) Determine whether the given interface is a common Java language interface:Serializable
,Externalizable
,Closeable
,AutoCloseable
,Cloneable
,Comparable
- all of which can be ignored when looking for 'primary' user-level interfaces.static boolean
isLambdaClass
(Class<?> clazz) Determine if the suppliedClass
is a JVM-generated implementation class for a lambda expression or method reference.static boolean
isPresent
(String className, ClassLoader classLoader) Determine whether theClass
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
isStaticClass
(Class<?> clazz) Determine if the supplied class is a static class.static boolean
isUserLevelMethod
(Method method) Determine whether the given method is declared by the user or at least pointing to a user-declared method.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<?>
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 givenCollection
into aClass
array.
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Field Details
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ARRAY_SUFFIX
Suffix for array class names:"[]"
.- See Also:
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CGLIB_CLASS_SEPARATOR
The CGLIB class separator:"$$"
.- See Also:
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CLASS_FILE_SUFFIX
The ".class" file suffix.- See Also:
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Constructor Details
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ClassUtils
public ClassUtils()
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Method Details
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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 anull
ClassLoader reference as well).- Returns:
- the default ClassLoader (only
null
if even the system ClassLoader isn't accessible) - See Also:
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overrideThreadContextClassLoader
@Nullable public static ClassLoader overrideThreadContextClassLoader(@Nullable 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
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forName
public static Class<?> forName(String name, @Nullable ClassLoader classLoader) throws ClassNotFoundException, LinkageError Replacement forClass.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 nested class names in Java source style (e.g. "java.lang.Thread.State" instead of "java.lang.Thread$State").- Parameters:
name
- the name of the ClassclassLoader
- the class loader to use (may benull
, which indicates the default class loader)- Returns:
- a class instance for the supplied name
- Throws:
ClassNotFoundException
- if the class was not foundLinkageError
- if the class file could not be loaded- See Also:
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resolveClassName
public static Class<?> resolveClassName(String className, @Nullable 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 ClassclassLoader
- the class loader to use (may benull
, which indicates the default class loader)- Returns:
- a 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)IllegalStateException
- if the corresponding class is resolvable but there was a readability mismatch in the inheritance hierarchy of the class (typically a missing dependency declaration in a Jigsaw module definition for a superclass or interface implemented by the class to be loaded here)- See Also:
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isPresent
Determine whether theClass
identified by the supplied name is present and can be loaded. Will returnfalse
if either the class or one of its dependencies is not present or cannot be loaded.- Parameters:
className
- the name of the class to checkclassLoader
- the class loader to use (may benull
which indicates the default class loader)- Returns:
- whether the specified class is present (including all of its superclasses and interfaces)
- Throws:
IllegalStateException
- if the corresponding class is resolvable but there was a readability mismatch in the inheritance hierarchy of the class (typically a missing dependency declaration in a Jigsaw module definition for a superclass or interface implemented by the class to be checked here)
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isVisible
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 benull
in which case this method will always returntrue
)
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isCacheSafe
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 analyzeclassLoader
- the ClassLoader to potentially cache metadata in (may benull
which indicates the system class loader)
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resolvePrimitiveClassName
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
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isPrimitiveWrapper
Check if the given class represents a primitive wrapper, i.e. Boolean, Byte, Character, Short, Integer, Long, Float, Double, or Void.- Parameters:
clazz
- the class to check- Returns:
- whether the given class is a primitive wrapper class
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isPrimitiveOrWrapper
Check if the given class represents a primitive (i.e. boolean, byte, char, short, int, long, float, or double),void
, or a wrapper for those types (i.e. Boolean, Byte, Character, Short, Integer, Long, Float, Double, or Void).- Parameters:
clazz
- the class to check- Returns:
true
if the given class represents a primitive, void, or a wrapper class
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isPrimitiveArray
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
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isPrimitiveWrapperArray
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
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resolvePrimitiveIfNecessary
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
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isAssignable
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 typerhsType
- the value type that should be assigned to the target type- Returns:
- if the target type is assignable from the value type
- See Also:
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isAssignableValue
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 typevalue
- the value that should be assigned to the type- Returns:
- if the type is assignable from the value
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convertResourcePathToClassName
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
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convertClassNameToResourcePath
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
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addResourcePathToPackagePath
Return a path suitable for use withClassLoader.getResource
(also suitable for use withClass.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, althoughClassPathResource
is usually even more convenient.- Parameters:
clazz
- the Class whose package will be used as the baseresourceName
- the resource name to append. A leading slash is optional.- Returns:
- the built-up resource path
- See Also:
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classPackageAsResourcePath
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 toClassLoader.getResource()
. For it to be fed toClass.getResource
instead, a leading slash would also have to be prepended to the returned value.- Parameters:
clazz
- the input class. Anull
value or the default (empty) package will result in an empty string ("") being returned.- Returns:
- a path which represents the package name
- See Also:
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classNamesToString
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
- an array of Class objects- Returns:
- a String of form "[com.foo.Bar, com.foo.Baz]"
- See Also:
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classNamesToString
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 benull
)- Returns:
- a String of form "[com.foo.Bar, com.foo.Baz]"
- See Also:
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toClassArray
Copy the givenCollection
into aClass
array.The
Collection
must containClass
elements only.- Parameters:
collection
- theCollection
to copy- Returns:
- the
Class
array - Since:
- 3.1
- See Also:
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getAllInterfaces
Return all interfaces that the given instance implements as an array, including ones implemented by superclasses.- Parameters:
instance
- the instance to analyze for interfaces- Returns:
- all interfaces that the given instance implements as an array
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getAllInterfacesForClass
Return all interfaces that the given class implements as an 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 an array
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getAllInterfacesForClass
public static Class<?>[] getAllInterfacesForClass(Class<?> clazz, @Nullable ClassLoader classLoader) Return all interfaces that the given class implements as an 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 interfacesclassLoader
- the ClassLoader that the interfaces need to be visible in (may benull
when accepting all declared interfaces)- Returns:
- all interfaces that the given object implements as an array
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getAllInterfacesAsSet
Return all interfaces that the given instance implements as a Set, including ones implemented by superclasses.- Parameters:
instance
- the instance to analyze for interfaces- Returns:
- all interfaces that the given instance implements as a Set
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getAllInterfacesForClassAsSet
Return all interfaces that the given class implements as a 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 a Set
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getAllInterfacesForClassAsSet
public static Set<Class<?>> getAllInterfacesForClassAsSet(Class<?> clazz, @Nullable ClassLoader classLoader) Return all interfaces that the given class implements as a 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 interfacesclassLoader
- the ClassLoader that the interfaces need to be visible in (may benull
when accepting all declared interfaces)- Returns:
- all interfaces that the given object implements as a Set
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createCompositeInterface
public static Class<?> createCompositeInterface(Class<?>[] interfaces, @Nullable 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 mergeclassLoader
- the ClassLoader to create the composite Class in- Returns:
- the merged interface as Class
- Throws:
IllegalArgumentException
- if the specified interfaces expose conflicting method signatures (or a similar constraint is violated)- See Also:
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determineCommonAncestor
@Nullable public static Class<?> determineCommonAncestor(@Nullable Class<?> clazz1, @Nullable Class<?> clazz2) Determine the common ancestor of the given classes, if any.- Parameters:
clazz1
- the class to introspectclazz2
- 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 isnull
, the other class will be returned. - Since:
- 3.2.6
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isJavaLanguageInterface
Determine whether the given interface is a common Java language interface:Serializable
,Externalizable
,Closeable
,AutoCloseable
,Cloneable
,Comparable
- all of which can be ignored when looking for 'primary' user-level interfaces. Common characteristics: no service-level operations, no bean property methods, no default methods.- Parameters:
ifc
- the interface to check- Since:
- 5.0.3
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isStaticClass
Determine if the supplied class is a static class.- Returns:
true
if the supplied class is a static class- Since:
- 6.0
- See Also:
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isInnerClass
Determine if the supplied class is an inner class, i.e. a non-static member of an enclosing class.- Returns:
true
if the supplied class is an inner class- Since:
- 5.0.5
- See Also:
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isLambdaClass
Determine if the suppliedClass
is a JVM-generated implementation class for a lambda expression or method reference.This method makes a best-effort attempt at determining this, based on checks that work on modern, mainstream JVMs.
- Parameters:
clazz
- the class to check- Returns:
true
if the class is a lambda implementation class- Since:
- 5.3.19
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isCglibProxy
Deprecated.as of 5.2, in favor of custom (possibly narrower) checks such as for a Spring AOP proxyCheck whether the given object is a CGLIB proxy.- Parameters:
object
- the object to check- See Also:
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isCglibProxyClass
Deprecated.as of 5.2, in favor of custom (possibly narrower) checks or simply a check for containingCGLIB_CLASS_SEPARATOR
Check whether the specified class is a CGLIB-generated class.- Parameters:
clazz
- the class to check- See Also:
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isCglibProxyClassName
Deprecated.as of 5.2, in favor of custom (possibly narrower) checks or simply a check for containingCGLIB_CLASS_SEPARATOR
Check whether the specified class name is a CGLIB-generated class.- Parameters:
className
- the class name to check- See Also:
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getUserClass
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
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getUserClass
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
- See Also:
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getDescriptiveType
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
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matchesTypeName
Check whether the given class matches the user-specified type name.- Parameters:
clazz
- the class to checktypeName
- the type name to match
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getShortName
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
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getShortName
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
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getShortNameAsProperty
Return the short string name of a Java class in uncapitalized JavaBeans property format. Strips the outer class name in case of a nested class.- Parameters:
clazz
- the class- Returns:
- the short name rendered in a standard JavaBeans property format
- See Also:
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getClassFileName
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
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getPackageName
Determine the name of the package of the given class, e.g. "java.lang" for thejava.lang.String
class.- Parameters:
clazz
- the class- Returns:
- the package name, or the empty String if the class is defined in the default package
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getPackageName
Determine the name of the package of the given fully-qualified class name, e.g. "java.lang" for thejava.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
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getQualifiedName
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
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getQualifiedMethodName
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
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getQualifiedMethodName
Return the qualified name of the given method, consisting of fully qualified interface/class name + "." + method name.- Parameters:
method
- the methodclazz
- the clazz that the method is being invoked on (may benull
to indicate the method's declaring class)- Returns:
- the qualified name of the method
- Since:
- 4.3.4
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hasConstructor
Determine whether the given class has a public constructor with the given signature.Essentially translates
NoSuchMethodException
to "false".- Parameters:
clazz
- the clazz to analyzeparamTypes
- the parameter types of the method- Returns:
- whether the class has a corresponding constructor
- See Also:
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getConstructorIfAvailable
@Nullable 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 returnnull
).Essentially translates
NoSuchMethodException
tonull
.- Parameters:
clazz
- the clazz to analyzeparamTypes
- the parameter types of the method- Returns:
- the constructor, or
null
if not found - See Also:
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hasMethod
Determine whether the given class has a public method with the given signature.- Parameters:
clazz
- the clazz to analyzemethod
- the method to look for- Returns:
- whether the class has a corresponding method
- Since:
- 5.2.3
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hasMethod
Determine whether the given class has a public method with the given signature.Essentially translates
NoSuchMethodException
to "false".- Parameters:
clazz
- the clazz to analyzemethodName
- the name of the methodparamTypes
- the parameter types of the method- Returns:
- whether the class has a corresponding method
- See Also:
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getMethod
Determine whether the given class has a public method with the given signature, and return it if available (else throws anIllegalStateException
).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
toIllegalStateException
.- Parameters:
clazz
- the clazz to analyzemethodName
- the name of the methodparamTypes
- the parameter types of the method (may benull
to indicate any signature)- Returns:
- the method (never
null
) - Throws:
IllegalStateException
- if the method has not been found- See Also:
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getMethodIfAvailable
@Nullable public static Method getMethodIfAvailable(Class<?> clazz, String methodName, @Nullable Class<?>... paramTypes) Determine whether the given class has a public method with the given signature, and return it if available (else returnnull
).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
tonull
.- Parameters:
clazz
- the clazz to analyzemethodName
- the name of the methodparamTypes
- the parameter types of the method (may benull
to indicate any signature)- Returns:
- the method, or
null
if not found - See Also:
-
getMethodCountForName
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 checkmethodName
- the name of the method- Returns:
- the number of methods with the given name
-
hasAtLeastOneMethodWithName
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 checkmethodName
- the name of the method- Returns:
- whether there is at least one method with the given name
-
getMostSpecificMethod
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 — for example, the method may beIFoo.bar()
, and the target class may beDefaultFoo
. In this case, the method may beDefaultFoo.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 bridge methods automatically. CallBridgeMethodResolver.findBridgedMethod(java.lang.reflect.Method)
if bridge method resolution is desirable — for example, to obtain metadata from the original method definition.NOTE: If Java security settings disallow reflective access — for example, 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 interfacetargetClass
- the target class for the current invocation (may benull
or may not even implement the method)- Returns:
- the specific target method, or the original method if the
targetClass
does not implement it - See Also:
-
getInterfaceMethodIfPossible
Deprecated.in favor ofgetInterfaceMethodIfPossible(Method, Class)
Determine a corresponding interface method for the given method handle, if possible.This is particularly useful for arriving at a public exported type on Jigsaw which can be reflectively invoked without an illegal access warning.
- Parameters:
method
- the method to be invoked, potentially from an implementation class- Returns:
- the corresponding interface method, or the original method if none found
- Since:
- 5.1
-
getInterfaceMethodIfPossible
Determine a corresponding interface method for the given method handle, if possible.This is particularly useful for arriving at a public exported type on Jigsaw which can be reflectively invoked without an illegal access warning.
- Parameters:
method
- the method to be invoked, potentially from an implementation classtargetClass
- the target class to check for declared interfaces- Returns:
- the corresponding interface method, or the original method if none found
- Since:
- 5.3.16
- See Also:
-
isUserLevelMethod
Determine whether the given method is declared by the user or at least pointing to a user-declared method.Checks
Method.isSynthetic()
(for implementation methods) as well as theGroovyObject
interface (for interface methods; on an implementation class, implementations of theGroovyObject
methods will be marked as synthetic anyway). Note that, despite being synthetic, bridge methods (Method.isBridge()
) are considered as user-level methods since they are eventually pointing to a user-declared generic method.- Parameters:
method
- the method to check- Returns:
true
if the method can be considered as user-declared;false
otherwise
-
getStaticMethod
Return a public static method of a class.- Parameters:
clazz
- the class which defines the methodmethodName
- the static method nameargs
- 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
-
getInterfaceMethodIfPossible(Method, Class)