JsonFormat.java 文件源码

/** Prints wrapper types (e.g., google.protobuf.Int32Value) */
private void printWrapper(MessageOrBuilder message) throws IOException {
  Descriptor descriptor = message.getDescriptorForType();
  FieldDescriptor valueField = descriptor.findFieldByName("value");
  if (valueField == null) {
    throw new InvalidProtocolBufferException("Invalid Wrapper type.");
  }
  // When formatting wrapper types, we just print its value field instead of
  // the whole message.
  printSingleFieldValue(valueField, message.getField(valueField));
}