DescriptorGenerator.java 文件源码

private FieldDescriptorProto generateField(Field field) {
  FieldDescriptorProto.Builder builder = FieldDescriptorProto.newBuilder();
  builder.setName(getFieldName(field));
  builder.setNumber(field.getNumber());
  builder.setLabel(toLabel(field.getCardinality()));
  builder.setType(toType(field.getKind()));
  if (field.getKind() == Kind.TYPE_ENUM
      || field.getKind() == Kind.TYPE_MESSAGE
      || field.getKind() == Kind.TYPE_GROUP) {
    builder.setTypeName(getTypeName(field.getTypeUrl()));
  }
  // NOTE: extendee not supported
  // NOTE: default_value not supported
  if (field.getOneofIndex() != 0) {
    // Index in the containing type's oneof_decl is zero-based.
    // Index in google.protobuf.type.Field.oneof_index is one-based.
    builder.setOneofIndex(field.getOneofIndex() - 1);
  }
  if (!Strings.isNullOrEmpty(field.getDefaultValue())) {
    builder.setDefaultValue(field.getDefaultValue());
  }
  FieldOptions options = getFieldOptions(field);
  if (!options.equals(FieldOptions.getDefaultInstance())) {
    builder.setOptions(options);
  }
  return builder.build();
}