AnnotationFactory.java 文件源码

/**
 * Processes a method invocation request to this annotation instance.
 * Recognizes the methods declared in the
 * {@link java.lang.annotation.Annotation java.lang.annotation.Annotation}
 * interface, and member-defining methods of the implemented annotation type.
 * @throws IllegalArgumentException If the specified method is none of the above
 * @return the invocation result
 */
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
{
    String name = method.getName();
    Class[] params = method.getParameterTypes();
    if (params.length == 0) {
        if ("annotationType".equals(name)) {
            return klazz;
        } else if ("toString".equals(name)) {
            return toString();
        } else if ("hashCode".equals(name)) {
            return hashCode();
        }

        // this must be element value request
        AnnotationMember element = null;
        for (AnnotationMember el : elements) {
            if (name.equals(el.name)) {
                element = el;
                break;
            }
        }
        if (element == null || !method.equals(element.definingMethod)) {
            throw new IllegalArgumentException(method.toString());
        } else {
            Object value = element.validateValue();
            if (value == null) {
                throw new IncompleteAnnotationException(klazz, name);
            }
            return value;
        }
    } else if (params.length == 1 && params[0] == Object.class && "equals".equals(name)){
        return Boolean.valueOf(equals(args[0]));
    }
    throw new IllegalArgumentException(
            "Invalid method for annotation type: " + method);
}