private T findObjectConverter()

in johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MapperConfig.java [325:405]
59 lines of code
19 McCabe index (conditional complexity)

    private <T> T findObjectConverter(final Class clazz,
                                      final Map<Class<?>, T> from,
                                      final Map<Class<?>, T> cache) {
        if (clazz == null) {
            throw new IllegalArgumentException("clazz must not be null");
        }

        // first lets look in our cache
        T converter = cache.get(clazz);
        if (converter != null && converter != NO_CONVERTER) {
            return converter;
        }

        // if we have found a dummy, we return null
        if (converter == NO_CONVERTER) {
            return null;
        }

        // we get called the first time for this class
        // lets search...

        Map<Class<?>, T> matchingConverters = new HashMap<Class<?>, T>();

        for (Map.Entry<Class<?>, T> entry : from.entrySet()) {

            if (clazz == entry.getKey()) {
                converter = entry.getValue();
                break;
            }

            if (entry.getKey().isAssignableFrom(clazz)) {
                matchingConverters.put(entry.getKey(), entry.getValue());
            }
        }

        if (converter != null) {
            cache.put(clazz, converter);
            return converter;
        }

        if (matchingConverters.isEmpty()) {
            cache.put(clazz, (T) NO_CONVERTER);
            return null;
        }

        // search the most significant
        Class toProcess = clazz;
        while (toProcess != null && converter == null) {

            converter = matchingConverters.get(toProcess);
            if (converter != null) {
                break;
            }

            Class[] interfaces = toProcess.getInterfaces();
            if (interfaces.length > 0) {
                for (Class interfaceToSearch : interfaces) {

                    converter = matchingConverters.get(interfaceToSearch);
                    if (converter != null) {
                        break;
                    }
                }
            }

            if (converter == null && toProcess.isInterface()) {
                converter = matchingConverters.get(Object.class);
                break;
            }

            toProcess = toProcess.getSuperclass();
        }

        if (converter == null) {
            cache.put(clazz, (T) NO_CONVERTER);
        } else {
            cache.put(clazz, converter);
        }

        return converter;
    }