AWS/Android 无法计算 md5 哈希答案

【问题标题】：AWS/Android Unable to calculate md5 hashAWS/Android 无法计算 md5 哈希
【发布时间】：2013-12-04 14:09:54
【问题描述】：

我正在自定义 Amazon 的 S3 Uploader 示例程序以满足我的需要。创建存储桶后，我将视频上传到其中。

PutObjectRequest por = new PutObjectRequest(buckets.get(0).getName(), Constants.VIDEO_NAME, new java.io.File(filePath));

当我运行上面的行时，我得到下面的异常：

Unable to calculate MD5 has: /storage/....../bla.mp4: open failed: EACCES (Permission Denied)

堆栈跟踪：

12-04 14:39:21.981  29372-29441/com.amazonaws.demo.s3uploader E/ERR﹕ com.amazonaws.AmazonClientException: Unable to calculate MD5 hash: /storage/emulated/0/DCIM/Camera/VID_20131203_180120.mp4: open failed: EACCES (Permission denied)
            at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1139)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:160)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:120)
            at android.os.AsyncTask$2.call(AsyncTask.java:288)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:841)
     Caused by: java.io.FileNotFoundException: /storage/emulated/0/DCIM/Camera/VID_20131203_180120.mp4: open failed: EACCES (Permission denied)
            at libcore.io.IoBridge.open(IoBridge.java:409)
            at java.io.FileInputStream.<init>(FileInputStream.java:78)
            at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1135)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:160)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:120)
            at android.os.AsyncTask$2.call(AsyncTask.java:288)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:841)
     Caused by: libcore.io.ErrnoException: open failed: EACCES (Permission denied)
            at libcore.io.Posix.open(Native Method)
            at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
            at libcore.io.IoBridge.open(IoBridge.java:393)
            at java.io.FileInputStream.<init>(FileInputStream.java:78)
            at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1135)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:160)
            at com.amazonaws.demo.s3uploader.S3UploaderActivity$S3PutObjectTask.doInBackground(S3UploaderActivity.java:120)
            at android.os.AsyncTask$2.call(AsyncTask.java:288)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
            at java.lang.Thread.run(Thread.java:841)

操作系统 = 4.4/KitKat，设备 = Nexus 4

发生了什么事？

【问题讨论】：

完整堆栈跟踪，设备版本。

标签： android amazon-web-services amazon-s3 md5

【解决方案1】：

不要像我一样。在尝试上传到 S3 之前检查文件是否存在。

【讨论】：

【解决方案2】：

在 KitKat 中，未经许可，您无法读取外部存储。

见

http://developer.android.com/about/versions/android-4.4.html#Behaviors

http://developer.android.com/reference/android/Manifest.permission.html#READ_EXTERNAL_STORAGE

【讨论】：

AND 可能必须调用 ActivityCompat.requestPermissions(...)