Union.java 文件源码

public static AnnotatedType of(AnnotatedType[] types) {
    Objects.requireNonNull(types);
    if (types.length < 2) {
        if (types.length == 1 && GenericTypeReflector.isSuperType(Union.class, types[0].getType())) {
            return types[0];
        }
        throw new IllegalArgumentException(SINGLE_TYPE_UNION_ERROR);
    }

    AnnotatedType[] distinctTypes = dedupe(types);
    Class union;
    try {
        union = ClassUtils.forName(Union.class.getName() + distinctTypes.length);
    } catch (ClassNotFoundException e) {
        throw new IllegalArgumentException("Unions of more than 10 types are not supported");
    }
    Annotation unionAnnotation = stream(ClassUtils.getAllAnnotations(stream(types)))
            .filter(annotation -> annotation.annotationType().equals(GraphQLUnion.class))
            .filter(annotation -> !((GraphQLUnion) annotation).description().isEmpty())
            .findFirst().orElse(types[0].getAnnotation(GraphQLUnion.class));
    return TypeFactory.parameterizedAnnotatedClass(union, new Annotation[] {unionAnnotation}, distinctTypes);
}