Package org.dellroad.stuff.java

Class AnnotationUtil

java.lang.Object

org.dellroad.stuff.java.AnnotationUtil

public final class AnnotationUtil
extends Object

Annotation utility methods.

Method Summary

Modifier and Type	Method	Description
static <A extends Annotation> void	applyAnnotationValues(Object bean, String methodPrefix, A annotation, A defaults, BiFunction<? super List<Method>,String,String> propertyFinder, Function<? super Class<?>,?> instantiator)	Read annotation values from the given annotation and apply those values to the corresponding properties of the given bean.
static <A extends Annotation> A	getAnnotation(Class<A> annotationType, Class<?> methodClass, String methodName, Class<?>... methodParameterTypes)	Introspect the specified method and read the specified annotation, which must exist.
static List<Annotation>	getAnnotations(Class<?> methodClass, String methodName, Class<?>... methodParameterTypes)	Introspect the specified method and read all annotations.

Methods inherited from class java.lang.Object

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

Method Details

getAnnotations

public static List<Annotation> getAnnotations(Class<?> methodClass,
 String methodName,
 Class<?>... methodParameterTypes)

Introspect the specified method and read all annotations.

Parameters:

methodClass - method's declaring class

methodName - method name

methodParameterTypes - method parameter types

Returns:

list of annotations found

Throws:

IllegalArgumentException - if method is not found

RuntimeException - if method cannot be instrospected

IllegalArgumentException - if any parameter is null

getAnnotation

public static <A extends Annotation> A getAnnotation(Class<A> annotationType,
 Class<?> methodClass,
 String methodName,
 Class<?>... methodParameterTypes)

Introspect the specified method and read the specified annotation, which must exist.

Type Parameters:

A - annotation type

Parameters:

annotationType - annotation to look for

methodClass - method's declaring class

methodName - method name

methodParameterTypes - method parameter types

Returns:

the annotation found

Throws:

IllegalArgumentException - if method is not found

RuntimeException - if method cannot be instrospected

IllegalArgumentException - if any parameter is null

applyAnnotationValues

public static <A extends Annotation> void applyAnnotationValues(Object bean,
 String methodPrefix,
 A annotation,
 A defaults,
 BiFunction<? super List<Method>,String,String> propertyFinder,
 Function<? super Class<?>,?> instantiator)

Read annotation values from the given annotation and apply those values to the corresponding properties of the given bean.

For example, if the annotation has a foo() property of type int, and bean has a method like setFoo(int), then the annotation value will be used to set the property using the method.

Properties that are Class instances result in instantiating the given class, unless the property actually has type Class.

The propertyFinder allows the caller to specify which annotation property should be used for the given setter method(s). In cases where there are multiple methods with the same name, all avilable methods are listed with those taking narrower parameter types listed first. If propertyFinder returns a non-null annotation property name, that value will be set using the first method in the list that accepts it.

Non-primitive array values are converted into Lists if necessary.

Type Parameters:

A - annotation type

Parameters:

bean - target bean

methodPrefix - setter method name prefix (typically "set")

annotation - annotation with properties

defaults - annotation with default values; if non-null, values in annotation equal to their default are skipped

propertyFinder - returns the annotation property name for given setter method with the given bean property name, or null if none

instantiator - used to instantiate new instances when annotation property has type Class

Throws:

IllegalArgumentException - if a required parameter is null

IllegalArgumentException - if a bean property is being set more than once

RuntimeException - if an unexpected error occurs