接收第三方系统的附件文件转为MultipartFile对象进行存储_接收第三方文件信息和附件

最近遇到一个和第三方系统系统对接，碰到的一个附件问题，由于没有指定标准，导致被牵着鼻子走，浪费了大量的时间，话不多说，上问题，及解决方法

遇到的问题：第三方系统推送附件，我这边使用MultipartFile 进行接收，是没问题的，但是一直出现附件上传服务器上下载下来打不开损坏了。后来想了一个办法之间传过来一个压缩包我接收保存，压缩包可以正常上传，下载，文件也没有问题，但是由于不能直接上传压缩包，只能是在代码里面解压压缩包，然后上传附件。

此时在解压的过程中也没有报错，但是又出现了老问题就是上传的附件下载下来损坏了，此时我就觉得可能是在读取文件的时候，转为MultipartFile对象的时候出问题（因为已经有写好的方法，直直接传参数就行），但是我通过接口测试工具测试还是可以上传压缩包，不能解压。

那会不会是文件读取的问题呢？

此时，我就将读取的文件输出到本地，果然，读取文件出现问题，那么问题已经定位到，哈哈哈

1.controller

@PostMapping("/createInstructions")
public AjaxResult createInstructions(HttpServletRequest request, HttpServletResponse response, @RequestParam(value = "file") MultipartFile file) {
        if (oaService.mapping(request, response, file)) {
            return AjaxResult.success();
        }
        return AjaxResult.error();
    }

2.service

boolean mapping(HttpServletRequest request, HttpServletResponse response,  MultipartFile file);

@Transactional
@Override
public boolean mapping(HttpServletRequest request, HttpServletResponse response,  MultipartFile file) {
MultipartFile multipartFile = null;
 
        String originalFilename = file.getOriginalFilename() ;
        if (!originalFilename.endsWith(".zip")){
            throw new RuntimeException( originalFilename+"文件格式错误请上传.zip");
        }
        List<MultipartFile> multipartFileList = new ArrayList<>();
        ZipArchiveInputStream zipInputStream = null;
        BufferedInputStream bufferedInputStream = null;
        String zipEntryFile;
        try {
            zipInputStream = new ZipArchiveInputStream(file.getInputStream(), Charset.forName("UTF-8").toString());
            bufferedInputStream = new BufferedInputStream(zipInputStream) ;
            ZipEntry zipEntry;
            while ((zipEntry = zipInputStream.getNextZipEntry()) != null){
                if (zipEntry.isDirectory()) {
                    continue;
                }else{
                    zipEntryFile = zipEntry.getName();
 
                    Assert.notNull(zipEntryFile,"压缩文件中子文件的名字格式不正确");
                    byte[] bytes = new byte[(int)zipEntry.getSize()];
                    bufferedInputStream.read(bytes,0,(int)zipEntry.getSize());
                    InputStream byteArrayInputStream = new ByteArrayInputStream(bytes);
 
                    String contentType = MediaTypeFactory.getMediaType(zipEntryFile).orElse(MediaType.APPLICATION_OCTET_STREAM).toString();
                    MultipartFile mockMultipartFile = new MockMultipartFile(zipEntryFile, zipEntryFile, contentType, byteArrayInputStream);
                    multipartFileList.add(multipartFile);
 
                    SysAttachment attachment = new SysAttachment();
                    Long fileId = SnowFlake.getId();
                    attachment.setFileid(fileId);
                    String tempFilePath = tempPath + SnowFlake.getId() + File.separator;
                    AjaxFileResult ajaxFileResult = sysAttachmentService.uploadServerFile(attachment, mockMultipartFile, tempFilePath);
                    Integer state = ajaxFileResult.getState();
                    if(state == 200){
                        SysAttachment sysAttachment = sysAttachmentService.selectSysAttachmentById(fileId);
                        OafileDetail detail = getOaDetail(sysAttachment,master.getId());
                        logger.info("OA文件细明对象--------detail:{}", detail);
                        oafileDetailMapper.insertSelective(detail); // oa文件细明对象
                        logger.info("OA______________detail表插入成功-------string");
                    }
 
                    FileOutputStream fileOutputStream = null;
                    try {
                        fileOutputStream = new FileOutputStream(tempPath + zipEntryFile);
                        byte[] buffer = new byte[1024];
                        int length;
                        while ((length = byteArrayInputStream.read(buffer)) > 0) {
                            fileOutputStream.write(buffer, 0, length);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
 
                    multipartFileList.add(multipartFile);
                    byteArrayInputStream.close();
                }
            }
        } catch ( IOException e){
            e.printStackTrace();
        }finally {
            if (bufferedInputStream!=null) {
                try {
                    bufferedInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (zipInputStream != null) {
                try {
                    zipInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
}

上述代码的问题：就是上传到服务器上下载下来损坏了，其实就是读取的时候出问题，优化后的代码如下：

@Transactional
@Override
public boolean mapping(HttpServletRequest request, HttpServletResponse response,  MultipartFile file) {
 
    try (ZipArchiveInputStream zipInputStream = new ZipArchiveInputStream(file.getInputStream(), Charset.forName("UTF-8").toString())) {
            ZipEntry zipEntry;
            while ((zipEntry = zipInputStream.getNextZipEntry()) != null) {
                if (zipEntry.isDirectory()) {
                    continue;
                } else {
                    String zipEntryFile = zipEntry.getName();
                    Assert.notNull(zipEntryFile, "压缩文件中子文件的名字格式不正确");
 
                    // 创建缓冲区
                    byte[] buffer = new byte[4096];
                    int bytesRead;
                    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
 
                    // 逐个读取文件内容
                    while ((bytesRead = zipInputStream.read(buffer, 0, buffer.length)) != -1) {
                        outputStream.write(buffer, 0, bytesRead);
                    }
 
                    // 创建MultipartFile对象
                    byte[] fileBytes = outputStream.toByteArray();
                    InputStream byteArrayInputStream = new ByteArrayInputStream(fileBytes);
                    String contentType = MediaTypeFactory.getMediaType(zipEntryFile).orElse(MediaType.APPLICATION_OCTET_STREAM).toString();
                    MultipartFile mockMultipartFile = new MockMultipartFile(zipEntryFile, zipEntryFile, contentType, byteArrayInputStream);
                    byteArrayInputStream.close();
                    outputStream.close();
 
                    // 上传文件并处理结果
                    SysAttachment attachment = new SysAttachment();
                    Long fileId = SnowFlake.getId();
                    attachment.setFileid(fileId);
                    String tempFilePath = tempPath + SnowFlake.getId() + File.separator;
                    AjaxFileResult ajaxFileResult = sysAttachmentService.uploadServerFile(attachment, mockMultipartFile, tempFilePath);
                    Integer state = ajaxFileResult.getState();
                    if (state == 200) {
                        SysAttachment sysAttachment = sysAttachmentService.selectSysAttachmentById(fileId);
                        OafileDetail detail = getOaDetail(sysAttachment, master.getId());
                        logger.info("文件细明对象--------detail:{}", detail);
                        oafileDetailMapper.insertSelective(detail); // oa文件细明对象
                        logger.info("OA______________detail表插入成功-------string");
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
 
 
}

为什么这样写就好了？

字节读取问题：在读取zipEntry的内容时，创建了一个大小为(int)zipEntry.getSize()的字节数组，并使用bufferedInputStream.read方法将字节数据读取到数组中。然而，这种方式可能会导致字节数组大小不足以容纳整个文件内容，从而导致文件损坏。为了解决这个问题，建议使用较小的缓冲区，逐个读取和写入文件内容，而不是一次性读取整个文件内容。