How to download file having spaces in it's name from azure by java service?

问题

I am creating application where I upload, download files in my azure storage account through java services. When I upload files with name having no space in their name(example : "image.png"), program returned me token successfully.

But when I try to get token while uploading or downloading for file names having spaces in between them like "new image.png" , it gives me error at particular line.

My code is :

CloudFile cloudFile = directory.getFileReference(fileNameWithExtension);
String tokenKey = testFileSAS(share, cloudFile);                                    
System.out.println(cloudFile.toString());
cloudFile.downloadToFile(DownloadTo);

Where as code to get the token is :

@Test
public String testFileSAS(CloudFileShare share, CloudFile file) throws InvalidKeyException, IllegalArgumentException, StorageException, URISyntaxException, InterruptedException {
    SharedAccessFilePolicy policy = createSharedAccessPolicy(
            EnumSet.of(SharedAccessFilePermissions.READ,
                       SharedAccessFilePermissions.LIST, 
                       SharedAccessFilePermissions.WRITE), 
        100);
    FileSharePermissions perms = new FileSharePermissions();
    perms.getSharedAccessPolicies().put("readperm", policy);

    share.uploadPermissions(perms);
    CloudFile sasFile = new CloudFile(new URI(file.getUri().toString() 
                       + "?" + file.generateSharedAccessSignature(null, "readperm")));
    System.out.println("sasFile==========="+sasFile.getName());
    sasFile.download(new ByteArrayOutputStream());
    CloudFile fileFromUri = new CloudFile(PathUtility.addToQuery(file.getStorageUri(), 
                    file.generateSharedAccessSignature(null, "readperm")));
    assertEquals(StorageCredentialsSharedAccessSignature.class.toString(),          
            fileFromUri.getServiceClient().getCredentials().getClass().toString());

    StorageCredentials creds = new StorageCredentialsSharedAccessSignature(
                file.generateSharedAccessSignature(policy, null, null));
    System.out.println("Generated SAS token is : " + file.generateSharedAccessSignature(policy, null, null));
    String token = file.generateSharedAccessSignature(policy, null, null);
    CloudFileClient client = new CloudFileClient(sasFile.getServiceClient().getStorageUri(), creds);

    CloudFile fileFromClient = client.getShareReference(file.getShare().getName()).getRootDirectoryReference()
                .getFileReference(file.getName());
    assertEquals(StorageCredentialsSharedAccessSignature.class.toString(),
            fileFromClient.getServiceClient().getCredentials().getClass().toString());
    assertEquals(client, fileFromClient.getServiceClient());

    return token;
}

I get error at this line :

sasFile.download(new ByteArrayOutputStream());

I think it is because when there is space in file names, it takes %20 in place of space and because of this, it can't get the file and gives the error.

What should I do to perform desired operation?

回答1:

I tried to reproduce your issue successfully, and got the error information via Fiddler as below.

<Error>
    <Code>AuthenticationFailed</Code>
    <Message>
Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature. RequestId:237ce8e7-001a-000d-57df-e4c9be000000 Time:2017-06-14T07:28:17.0520478Z
    </Message>
    <AuthenticationErrorDetail>
Signed expiry must be specified in signature or SAS identifier
    </AuthenticationErrorDetail>
</Error>

The issue was caused by the incorrect SAS token, not by a file name having spaces. So I change your code below to make it works when I set the expiry time for policy, although I don't know the implementation of your method createSharedAccessPolicy.

SharedAccessFilePolicy policy = new SharedAccessFilePolicy();
policy.setPermissions(EnumSet.of(SharedAccessFilePermissions.READ,
               SharedAccessFilePermissions.LIST, 
               SharedAccessFilePermissions.WRITE));
// Set expiry time for policy, and then it works.
policy.setSharedAccessExpiryTime(new Date(new Date().getTime()+3600));
FileSharePermissions perms = new FileSharePermissions();
perms.getSharedAccessPolicies().put("readperm", policy);
share.uploadPermissions(perms); 
String uri = file.getUri().toString() 
        + "?" + file.generateSharedAccessSignature(null, "readperm");
CloudFile sasFile = new CloudFile(new URI(uri));
System.out.println("sasFile==========="+sasFile.getName());
sasFile.download(new ByteArrayOutputStream());

来源：https://stackoverflow.com/questions/44450473/how-to-download-file-having-spaces-in-its-name-from-azure-by-java-service