Java将doc文件转成docx文件，并将两个文件合并在一起

private String downloadDailyInspectionDocByTemplate(List<WorkOrderWorkloadTableDownloadTemplate> itemList, String fileName) {
    //日常巡检登记表2024-11.14-11.20
    //20241212_20241218工作量
    String date = fileName.substring(0, fileName.indexOf("工"));
    String startYear = date.substring(0, 4);
    String startMonth = date.substring(4, 6);
    String startDay = date.substring(6, 8);

    String endYear = date.substring(9, 13);
    String endMonth = date.substring(13, 15);
    String endDay = date.substring(15, 17);

    String docName = "日常巡检登记表" + startYear + "-" + startMonth + "." + startDay + "-" + endMonth + "." + endDay + ".doc";
    String docPath = System.getProperty("user.dir") + File.separator;
    File docFile = new File(docPath + docName);
    String templateFilePath = this.getClass().getClassLoader().getResource("").getPath() + "template/DailyInspectionTemplate.ftl";
    String path = templateFilePath.substring(0, templateFilePath.lastIndexOf("/"));
    String templateName = templateFilePath.substring(templateFilePath.lastIndexOf("/") + 1);
    List<File> fileArrayList = new ArrayList<>();
    try (FileOutputStream out = new FileOutputStream(docFile);
         Writer writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8))) {
        Configuration configuration = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);
        configuration.setDefaultEncoding("utf-8");
        //除了ClassForTemplateLoading外，另一种模板加载方式DirectoryForTemplateLoading，也可用
        configuration.setDirectoryForTemplateLoading(new File(path));
        //加载模板
        Template template = configuration.getTemplate(templateName);