Map<String, Object> attachment = new HashMap<String, Object>();
        attachment.put("content", attachmentContent);
        attachment.put("_indexed_chars", -1); // no limit

        fileProperties.put("file", attachment);
        fileProperties.put("postID", postID);
        fileProperties.put("filename", file.getFilename());
        fileProperties.put("path", file.getPath());
        fileProperties.put("fileSize", file.getFileSize());

        UpdateResponse updateResponse = new UpdateRequestBuilder(transportClient,
                "threads",
                "thread,
                threadID)
                .setScript("ctx._source.files += file")
                .addScriptParam("file", fileProperties)
                .execute().actionGet();