package org.infinispan.cdi.common.util;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.spi.AnnotatedMethod;
import javax.enterprise.inject.spi.Bean;
import javax.enterprise.inject.spi.BeanManager;
import javax.enterprise.inject.spi.InjectionPoint;
/**
* <p>
* Allows an {@link AnnotatedMethod} to be injected using the CDI type safe
* resolution rules.
* </p>
* <p/>
* <p>
* {@link ParameterValueRedefiner} allows the default value to be overridden by
* the caller of
* {@link #invoke(Object, CreationalContext, ParameterValueRedefiner)}.
* </p>
*
* @param <X> the declaring type
* @author Pete Muir
*/
public class InjectableMethod<X> {
private final AnnotatedMethod<X> method;
private final List<InjectionPoint> parameters;
private final BeanManager beanManager;
/**
* Instantiate a new {@link InjectableMethod}.
*
* @param method the method which will be injected upon a call to
* {@link #invoke(Object, CreationalContext)}
* @param bean the bean which defines the injectable method
* @param beanManager the {@link BeanManager} to use to obtain the parameter
* values
*/
public InjectableMethod(AnnotatedMethod<X> method, Bean<?> declaringBean, BeanManager beanManager) {
this(method, Beans.createInjectionPoints(method, declaringBean, beanManager), beanManager);
}
/**
* Instantiate a new {@link InjectableMethod}.
*
* @param method the method which will be injected upon a call to
* {@link #invoke(Object, CreationalContext)}
* @param parameters a collection of injection points representing the
* parameters of the method
* @param beanManager the {@link BeanManager} to use to obtain the parameter
* values
*/
public InjectableMethod(AnnotatedMethod<X> method, Collection<InjectionPoint> parameters, BeanManager beanManager) {
this.method = method;
this.parameters = new ArrayList<InjectionPoint>(parameters);
this.beanManager = beanManager;
}
/**
* Get the bean manager used by this injectable method.
*
* @return the bean manager in use
*/
protected BeanManager getBeanManager() {
return beanManager;
}
/**
* Get the injectable parameters of this method.
*
* @return a collection of injection points representing the parameters of
* this method
*/
protected List<InjectionPoint> getParameters() {
return parameters;
}
/**
* Invoke the method, causing all parameters to be injected according to the
* CDI type safe resolution rules.
*
* @param <T> the return type of the method
* @param receiver the instance upon which to call the method
* @param creationalContext the creational context to use to obtain
* injectable references for each parameter
* @return the result of invoking the method or null if the method's return
* type is void
* @throws RuntimeException if this <code>Method</code> object enforces Java
* language access control and the underlying method is
* inaccessible or if the underlying method throws an exception or
* if the initialization provoked by this method fails.
* @throws IllegalArgumentException if the method is an instance method and
* the specified <code>receiver</code> argument is not an instance
* of the class or interface declaring the underlying method (or
* of a subclass or implementor thereof); if an unwrapping
* conversion for primitive arguments fails; or if, after possible
* unwrapping, a parameter value cannot be converted to the
* corresponding formal parameter type by a method invocation
* conversion.
* @throws NullPointerException if the specified <code>receiver</code> is
* null and the method is an instance method.
* @throws ExceptionInInitializerError if the initialization provoked by this
* method fails.
*/
public <T> T invoke(Object receiver, CreationalContext<T> creationalContext) {
return invoke(receiver, creationalContext, null);
}
/**
* Invoke the method, calling the parameter redefiner for each parameter,
* allowing the caller to override the default value obtained via the CDI
* type safe resolver.
*
* @param <T> the return type of the method
* @param receiver the instance upon which to call the method
* @param creationalContext the creational context to use to obtain
* injectable references for each parameter
* @return the result of invoking the method or null if the method's return
* type is void
* @throws RuntimeException if this <code>Method</code> object enforces Java
* language access control and the underlying method is
* inaccessible or if the underlying method throws an exception or
* if the initialization provoked by this method fails.
* @throws IllegalArgumentException if the method is an instance method and
* the specified <code>receiver</code> argument is not an instance
* of the class or interface declaring the underlying method (or
* of a subclass or implementor thereof); if an unwrapping
* conversion for primitive arguments fails; or if, after possible
* unwrapping, a parameter value cannot be converted to the
* corresponding formal parameter type by a method invocation
* conversion.
* @throws NullPointerException if the specified <code>receiver</code> is
* null and the method is an instance method.
* @throws ExceptionInInitializerError if the initialization provoked by this
* method fails.
*/
public <T> T invoke(Object receiver, CreationalContext<T> creationalContext, ParameterValueRedefiner redefinition) {
List<Object> parameterValues = new ArrayList<Object>();
for (int i = 0; i < getParameters().size(); i++) {
if (redefinition != null) {
ParameterValueRedefiner.ParameterValue value = new ParameterValueRedefiner.ParameterValue(i, getParameters().get(i), getBeanManager());
parameterValues.add(redefinition.redefineParameterValue(value));
} else {
parameterValues.add(getBeanManager().getInjectableReference(getParameters().get(i), creationalContext));
}
}
@SuppressWarnings("unchecked")
T result = (T) Reflections.invokeMethod(true, method.getJavaMember(), receiver, parameterValues.toArray(Reflections.EMPTY_OBJECT_ARRAY));
return result;
}
}