直接贴代码

    @GetMapping("/writeDataToFile")
    public void writeDataToFile(String jsonStr) throws IOException {
        //文件目录
        Path rootLocation = Paths.get("folder")
        if(Files.notExists(rootLocation)){
            Files.createDirectories(rootLocation);
        }
        //data.js是文件
        Path path = rootLocation.resolve("data.js");
        byte[] strToBytes = jsonStr.getBytes();
        Files.write(path, strToBytes);
    }