org.apache.juneau.internal

Class ReflectionUtils

java.lang.Object

org.apache.juneau.internal.ReflectionUtils

public final class ReflectionUtils
extends Object

Reflection utilities.

Constructor Summary

Constructors

Constructor and Description
ReflectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T extends Annotation> void	appendAnnotations(Class<T> a, Class<?> c, List<T> l) Finds and appends the specified annotation on the specified class and superclasses/interfaces to the specified list.
static <T extends Annotation> List<T>	findAnnotations(Class<T> a, Class<?> c) Returns all instances of the specified annotation on the specified class.
static <T extends Annotation> LinkedHashMap<Class<?>,T>	findAnnotationsMap(Class<T> a, Class<?> c) Same as findAnnotations(Class, Class) except returns the annotations as a map with the keys being the class on which the annotation was found.
static <T extends Annotation> LinkedHashMap<Class<?>,T>	findAnnotationsMapParentFirst(Class<T> a, Class<?> c) Same as findAnnotationsMap(Class, Class) except returns results in parent-to-child order.
static <T extends Annotation> List<T>	findAnnotationsParentFirst(Class<T> a, Class<?> c) Same as findAnnotations(Class, Class) but returns the list in parent-to-child order.
static <T extends Annotation> T	getAnnotation(Class<T> a, Class<?> c) Similar to Class.getAnnotation(Class) except also searches annotations on interfaces.
static <T extends Annotation> T	getDeclaredAnnotation(Class<T> a, Class<?> c) Returns the specified annotation only if it's been declared on the specified class.
static InputStream	getResource(Class<?> c, String name) Similar to Class.getResourceAsStream(String) except looks up the parent hierarchy for the existence of the specified resource.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionUtils

public ReflectionUtils()

Method Detail

getAnnotation

public static <T extends Annotation> T getAnnotation(Class<T> a,
                                                     Class<?> c)

Similar to Class.getAnnotation(Class) except also searches annotations on interfaces.

Type Parameters:

T - The annotation class type.

Parameters:

a - The annotation class.

c - The annotated class.

Returns:

The annotation, or null if not found.

getDeclaredAnnotation

public static <T extends Annotation> T getDeclaredAnnotation(Class<T> a,
                                                             Class<?> c)

Returns the specified annotation only if it's been declared on the specified class.

More efficient than calling Class.getAnnotation(Class) since it doesn't recursively look for the class up the parent chain.

Type Parameters:

T - The annotation class type.

Parameters:

a - The annotation class.

c - The annotated class.

Returns:

The annotation, or null if not found.

findAnnotations

public static <T extends Annotation> List<T> findAnnotations(Class<T> a,
                                                             Class<?> c)

Returns all instances of the specified annotation on the specified class.

Searches all superclasses and superinterfaces. Results are ordered child-to-parent.

Type Parameters:

T - The annotation class type.

Parameters:

a - The annotation class type.

c - The class being searched.

Returns:

The found matches, or an empty array if annotation was not found.

findAnnotationsParentFirst

public static <T extends Annotation> List<T> findAnnotationsParentFirst(Class<T> a,
                                                                        Class<?> c)

Same as findAnnotations(Class, Class) but returns the list in parent-to-child order.

Parameters:

a - The annotation class type.

c - The class being searched.

Returns:

The found matches, or an empty array if annotation was not found.

findAnnotationsMap

public static <T extends Annotation> LinkedHashMap<Class<?>,T> findAnnotationsMap(Class<T> a,
                                                                                  Class<?> c)

Same as findAnnotations(Class, Class) except returns the annotations as a map with the keys being the class on which the annotation was found.

Results are ordered child-to-parent.

Type Parameters:

T - The annotation class type.

Parameters:

a - The annotation class type.

c - The class being searched.

Returns:

The found matches, or an empty map if annotation was not found.

findAnnotationsMapParentFirst

public static <T extends Annotation> LinkedHashMap<Class<?>,T> findAnnotationsMapParentFirst(Class<T> a,
                                                                                             Class<?> c)

Same as findAnnotationsMap(Class, Class) except returns results in parent-to-child order.

Type Parameters:

T - The annotation class type.

Parameters:

a - The annotation class type.

c - The class being searched.

Returns:

The found matches, or an empty map if annotation was not found.

appendAnnotations

public static <T extends Annotation> void appendAnnotations(Class<T> a,
                                                            Class<?> c,
                                                            List<T> l)

Finds and appends the specified annotation on the specified class and superclasses/interfaces to the specified list.

Parameters:

a - The annotation.

c - The class.

l - The list of annotations.

getResource

public static InputStream getResource(Class<?> c,
                                      String name)

Similar to Class.getResourceAsStream(String) except looks up the parent hierarchy for the existence of the specified resource.

Parameters:

c - The class to return the resource on.

name - The resource name.

Returns:

An input stream on the specified resource, or null if the resource could not be found.