Method isNode

proj1a/tests/NodeChecker.java:19–97

This method checks whether a given class is a linked node or not. @param clazz the class you want to check @param doublyLinked whether or not the list can be doubly linked

(Class<?> clazz, boolean doublyLinked)

     * @param doublyLinked whether or not the list <em>can</em> be doubly linked
     */
    public static boolean isNode(Class<?> clazz, boolean doublyLinked) {
        // Get fields
        SortedSet<String> fields = Stream
                .of(clazz.getDeclaredFields())
                .filter(f -> !f.isSynthetic())
                .map(Field::getName)
                .collect(Collectors.toCollection(TreeSet::new));

        boolean hasData = false;
        int nodeFields = 0;

        // Check fields
        for (String field : fields) {
            Field f = null;
            try {
                f = clazz.getDeclaredField(field);
                f.setAccessible(true);
            } catch (NoSuchFieldException ex) {
                ex.printStackTrace();
                fail();
            }

            if (f.getType().equals(clazz)) {
                // Linked to another node
                nodeFields++;
                if (nodeFields == 2 && !doublyLinked) {
                    // Returns false if the list is doubly linked
                    return false;
                } else if (nodeFields == 3) {
                    // Don't allow triply linked and up
                    return false;
                }
            } else if (f.getType().equals(Object.class)) {
                // Has a generic type to store data
                if (hasData) {
                    // Checks for multiple data fields
                    return false;
                }
                hasData = true;
            } else {
                return false;
            }
        }

        // Get constructors
        Constructor<?>[] constructors = clazz.getDeclaredConstructors();

        // Checks arguments to the constructors
        for (Constructor<?> c : constructors) {
            boolean hasGenericArgument = false;
            int nodeArguments = 0;
            Class<?>[] paramTypes = c.getParameterTypes();
            for (int i = 0; i < paramTypes.length; i++) {
                if (i == 0 && !Modifier.isStatic(clazz.getModifiers())) {
                    continue;
                }
                Class<?> type = paramTypes[i];
                if (type.equals(Object.class)) {