ProtobufExtensionLookup.java 文件源码

public ProtobufExtensionLookup add(Class<?> parent) {
  // find all the generated service extensions for the class specified
  for (Field field : parent.getFields()) {
    // skip anything that isn't a generated extension. should be fine as long as we dont start
    // mucking around with class loaders
    if (field.getType() != GeneratedMessage.GeneratedExtension.class) {
      continue;
    }

    try {
      GeneratedMessage.GeneratedExtension extension =
          (GeneratedMessage.GeneratedExtension) field.get(parent);
      Message defaultMessageInst = extension.getMessageDefaultInstance();
      this.fields.put(defaultMessageInst.getClass(), extension);
    } catch (IllegalAccessException e) {
      LOG.warn("Could not not access " + field + " for " + parent);
    }
  }
  return this;
}