ClassUtils.java 文件源码

private static AnnotatedType getCommonSuperType(List<AnnotatedType> types, Set<String> seenTypeCombos, AnnotatedType fallback) {
    if (types == null || types.isEmpty()) {
        throw new IllegalArgumentException("At least one type must be provided");
    }
    if (types.size() == 1) {
        return types.get(0);
    }
    Annotation[] mergedAnnotations = getMergedAnnotations(types.toArray(new AnnotatedType[types.size()]));
    if (types.stream().map(AnnotatedType::getType).allMatch(type -> type.equals(types.get(0).getType()))) {
        return GenericTypeReflector.replaceAnnotations(types.get(0), mergedAnnotations);
    }
    List<Class<?>> classes = types.stream().map(AnnotatedType::getType).map(ClassUtils::getRawType).collect(Collectors.toList());
    String typeNames = types.stream().map(type -> type.getType().getTypeName()).sorted().collect(Collectors.joining(","));
    if (seenTypeCombos.contains(typeNames)) {
        return fallbackOrException(fallback);
    }
    seenTypeCombos.add(typeNames);

    //deal with arrays first as they are special
    if (types.stream().allMatch(type -> type instanceof AnnotatedArrayType)) {
        List<AnnotatedType> componentTypes = types.stream()
                .map(type -> ((AnnotatedArrayType) type).getAnnotatedGenericComponentType())
                .collect(Collectors.toList());
        AnnotatedType componentType = getCommonSuperType(componentTypes, seenTypeCombos, fallback);
        return TypeFactory.arrayOf(componentType, mergedAnnotations);
    }

    Class<?> commonRawSuperType = getCommonSuperTypes(classes).get(0);
    if (classes.stream().noneMatch(ROOT_TYPES::contains) && ROOT_TYPES.contains(commonRawSuperType)) {
        return fallbackOrException(fallback);
    }
    List<AnnotatedType> normalizedTypes = types.stream()
            .map(type -> GenericTypeReflector.getExactSuperType(type, commonRawSuperType))
            .collect(Collectors.toList());
    if (normalizedTypes.stream().anyMatch(type -> GenericTypeReflector.isMissingTypeParameters(type.getType()))) {
        throw new TypeMappingException("Automatic type inference failed because some of the types are missing generic type parameter(s).");
    }
    if (normalizedTypes.stream().allMatch(type -> type.getType() instanceof Class)) {
        return annotate(commonRawSuperType, mergedAnnotations);
    }
    if (normalizedTypes.stream().allMatch(type -> type instanceof AnnotatedParameterizedType)) {
        AnnotatedType[] parameters = Arrays.stream(commonRawSuperType.getTypeParameters())
                .map(param -> normalizedTypes.stream().map(type -> GenericTypeReflector.getTypeParameter(type, param)).collect(Collectors.toList()))
                .map(paramTypes -> getCommonSuperType(paramTypes, seenTypeCombos, fallback))
                .toArray(AnnotatedType[]::new);
        return TypeFactory.parameterizedAnnotatedClass(commonRawSuperType, mergedAnnotations, parameters);
    }
    return fallbackOrException(fallback);
}