private static boolean isAssignable()

in bval-jsr/src/main/java/org/apache/bval/util/reflection/TypeUtils.java [285:336]
30 lines of code
12 McCabe index (conditional complexity)

    private static boolean isAssignable(final Type type, final Class<?> toClass) {
        if (type == null) {
            // consistency with ClassUtils.isAssignable() behavior
            return toClass == null || !toClass.isPrimitive();
        }

        // only a null type can be assigned to null type which
        // would have cause the previous to return true
        if (toClass == null) {
            return false;
        }

        // all types are assignable to themselves
        if (toClass.equals(type)) {
            return true;
        }

        if (type instanceof Class<?>) {
            // just comparing two classes
            // also take primitives into account!
            return isAssignable((Class<?>) type, toClass);
        }

        if (type instanceof ParameterizedType) {
            // only have to compare the raw type to the class
            return isAssignable(getRawType((ParameterizedType) type), toClass);
        }

        // *
        if (type instanceof TypeVariable<?>) {
            // if any of the bounds are assignable to the class, then the
            // type is assignable to the class.
            return Stream.of(((TypeVariable<?>) type).getBounds()).anyMatch(bound -> isAssignable(bound, toClass));
        }

        // the only classes to which a generic array type can be assigned
        // are class Object and array classes
        if (type instanceof GenericArrayType) {
            return Object.class.equals(toClass)
                    || toClass.isArray()
                    && isAssignable(((GenericArrayType) type).getGenericComponentType(), toClass
                            .getComponentType());
        }

        // wildcard types are not assignable to a class (though one would think
        // "? super Object" would be assignable to Object)
        if (type instanceof WildcardType) {
            return false;
        }

        throw new IllegalStateException("found an unhandled type: " + type);
    }