src/main/java/ca/jeb/protobuf/internal/ProtobufSerializerUtils.java
public static final Map<Field, ProtobufAttribute> getAllProtbufFields(Class<? extends Object> fromClazz)
  {
    Map<Field, ProtobufAttribute> protoBufFields = CLASS_TO_FIELD_MAP_CACHE.get(fromClazz.getCanonicalName());
    if (protoBufFields != null)
    {
      return protoBufFields;
    }
    else
    {
      protoBufFields = new HashMap<>();
    }

    final List<Field> fields = JReflectionUtils.getAllFields(new ArrayList<Field>(), fromClazz);

    for (Field field : fields)
    {
      final Annotation annotation = field.getAnnotation(ProtobufAttribute.class);
      if (annotation == null)
      {
        continue;
      }
      final ProtobufAttribute gpbAnnotation = (ProtobufAttribute)annotation;
      protoBufFields.put(field, gpbAnnotation);
    }

    // Caching to increase speed
    CLASS_TO_FIELD_MAP_CACHE.put(fromClazz.getCanonicalName(), protoBufFields);

    return protoBufFields;
  }
public static final Map<Field, ProtobufAttribute> getAllProtbufFields(Class<? extends Object> fromClazz)
  {
    Map<Field, ProtobufAttribute> protoBufFields = CLASS_TO_FIELD_MAP_CACHE.get(fromClazz.getCanonicalName());
    if (protoBufFields != null)
    {
      return protoBufFields;
    }
    else
    {
      protoBufFields = new HashMap<>();
    }

    final List<Field> fields = JReflectionUtils.getAllFields(new ArrayList<Field>(), fromClazz);

    for (Field field : fields)
    {
      final Annotation annotation = field.getAnnotation(ProtobufAttribute.class);
      if (annotation == null)
      {
        continue;
      }
      final ProtobufAttribute gpbAnnotation = (ProtobufAttribute)annotation;
      protoBufFields.put(field, gpbAnnotation);
    }

    // Caching to increase speed
    CLASS_TO_FIELD_MAP_CACHE.put(fromClazz.getCanonicalName(), protoBufFields);

    return protoBufFields;
  }
Returns a full mapping of all Protobuf fields from the POJO class.
Essentially, the only fields that will be returned if they have
the ProtobufAttribute annotation.

@param fromClazz - Class&lt;? extends Object&gt;
@return Map&lt;Field, ProtobufAttribute&gt;