AnnotationMember.java 文件源码

/**
 * Validates contained value against its member definition
 * and if ok returns the value.
 * Otherwise, if the value type mismatches definition 
 * or the value itself describes an error, 
 * throws appropriate exception.
 * <br> Note, this method may return null if this element was constructed 
 * with such value.  
 * 
 * @see #rethrowError()
 * @see #copyValue()
 * @return actual valid value or null if no value
 */
public Object validateValue() throws Throwable {
    if (tag == ERROR) {
        rethrowError();
    } 
    if (value == NO_VALUE) {
        return null;
    }
    if (elementType == value.getClass() 
            || elementType.isInstance(value)) { // nested annotation value
        return copyValue();
    } else {
        throw new AnnotationTypeMismatchException(definingMethod, 
                value.getClass().getName());
    }

}