对象存储 OSS数据完整性校验

详细解答可以参考官方帮助文档

因为移动端网络环境的复杂性，OSS SDK提供了基于MD5和CRC64的端到端的数据完整性验证功能。

MD5校验

需要在上传文件时提供文件的Content-MD5值，OSS服务器会帮助用户进行MD5校验，只有在OSS服务器计算接收到的文件得到的MD5值和上传提供的MD5一致时才可以上传成功，从而保证上传数据的一致性。

// 构造上传请求
PutObjectRequest put = new PutObjectRequest("<bucketName>", "<objectKey>", "<uploadFilePath>");
ObjectMetadata metadata = new ObjectMetadata();
metadata.setContentType("application/octet-stream");
try {
    // 设置Md5以便校验
    metadata.setContentMD5(BinaryUtil.calculateBase64Md5("<uploadFilePath>")); // 如果是从文件上传
    // metadata.setContentMD5(BinaryUtil.calculateBase64Md5(byte[])); // 如果是上传二进制数据
} catch (IOException e) {
    e.printStackTrace();
}
put.setMetadata(metadata);
OSSAsyncTask task = oss.asyncPutObject(put, new OSSCompletedCallback<PutObjectRequest, PutObjectResult>() {
    ...
});

CRC校验

与MD5相比，CRC64可以边上传边计算CRC值。

// 构造上传请求
PutObjectRequest put = new PutObjectRequest("<bucketName>", "<objectKey>", "<uploadFilePath>");
// 开启crc效验后。如果在传输中数据不一致，会直接抛出ClientException异常。提示InconsistentException: inconsistent object
put.setCRC64(OSSRequest.CRC64Config.YES);
OSSAsyncTask task = oss.asyncPutObject(put, new OSSCompletedCallback<PutObjectRequest, PutObjectResult>() {
     @Override
     public void onSuccess(PutObjectRequest request, PutObjectResult result) {
     //.....
     }
    @Override
    public void onFailure(PutObjectRequest request, ClientException clientExcepion, ServiceException serviceException) {
    //.....
        if (clientExcepion != null) {
            // client side exception,  such as network exception
            // 检查是否有InconsistentException: inconsistent object信息
            clientExcepion.getMessage();
         }
      }
});