Package com.exasol.bucketfs

Interface ReadOnlyBucket

All Known Subinterfaces:

Bucket, UnsynchronizedBucket

All Known Implementing Classes:

ReadEnabledBucket, SyncAwareBucket, WriteEnabledBucket

public interface ReadOnlyBucket

Interface for read-only bucket access.

Field Summary

Fields

Modifier and Type	Field	Description
static String	PATH_IN_UDF_PREFIX	Prefix for building UDF-visible paths to buckets in BucketFS.

Method Summary

Modifier and Type	Method	Description
void	downloadFile(String pathInBucket, Path localPath)	Download a file from a bucket to a local filesystem.
String	downloadFileAsString(String pathInBucket)	Download a file from a bucket into a string.
String	getBucketFsName()
String	getBucketName()
String	getFullyQualifiedBucketName()	Get the fully qualified name of the bucket.
default String	getPathInUdf()	Return the UDF-visible path to the root of this bucket within BucketFS.
default String	getPathInUdf(String fileInBucketFs)	Return the UDF-visible path to a specific file within this bucket in BucketFS.
String	getReadPassword()	Get the read password for the bucket.
List<String>	listContents()	List the contents of a bucket.
List<String>	listContents(String path)	List the contents of a path inside a bucket.
List<String>	listContentsRecursively()	Recursively list the contents of a bucket.
List<String>	listContentsRecursively(String path)	Recursively list the contents of a path inside a bucket.

Field Detail

PATH_IN_UDF_PREFIX

static final String PATH_IN_UDF_PREFIX

Prefix for building UDF-visible paths to buckets in BucketFS.

In Exasol, UDFs see BucketFS under /buckets/. This constant helps build correct file paths as seen from within UDFs.

See Also:

getPathInUdf(), getPathInUdf(String), Constant Field Values

Method Detail

getBucketFsName

String getBucketFsName()

Returns:

name of the BucketFS filesystem this bucket belongs to

getBucketName

String getBucketName()

Returns:

name of the bucket

getFullyQualifiedBucketName

String getFullyQualifiedBucketName()

Get the fully qualified name of the bucket.

Returns:

fully qualified name consisting of service name and bucket name

getReadPassword

String getReadPassword()

Get the read password for the bucket.

Returns:

read password

listContents

List<String> listContents()
                   throws BucketAccessException

List the contents of a bucket.

Returns:

bucket contents

Throws:

BucketAccessException - if the contents are not accessible or the path is invalid

listContentsRecursively

List<String> listContentsRecursively()
                              throws BucketAccessException

Recursively list the contents of a bucket.

Returns:

bucket contents

Throws:

BucketAccessException - if the contents are not accessible or the path is invalid

listContents

List<String> listContents(String path)
                   throws BucketAccessException

List the contents of a path inside a bucket.

Parameters:

path - relative path from the bucket root

Returns:

list of file system entries

Throws:

BucketAccessException - if the contents are not accessible or the path is invalid

listContentsRecursively

List<String> listContentsRecursively(String path)
                              throws BucketAccessException

Recursively list the contents of a path inside a bucket.

Parameters:

path - relative path from the bucket root

Returns:

list of file system entries

Throws:

BucketAccessException - if the contents are not accessible or the path is invalid

downloadFile

void downloadFile(String pathInBucket,
                  Path localPath)
           throws BucketAccessException

Download a file from a bucket to a local filesystem.

Parameters:

pathInBucket - path of the file in BucketFS

localPath - local path the file is downloaded to

Throws:

BucketAccessException - if the local file does not exist or is not accessible or if the download failed

downloadFileAsString

String downloadFileAsString(String pathInBucket)
                     throws BucketAccessException

Download a file from a bucket into a string.

Parameters:

pathInBucket - path of the file in BucketFS

Returns:

file contents as string

Throws:

BucketAccessException - if the local file does not exist or is not accessible or if the download failed

getPathInUdf

default String getPathInUdf()

Return the UDF-visible path to the root of this bucket within BucketFS.

This method ensures consistency and avoids human error by generating the correct chrooted path as seen from within a User-Defined Function (UDF) environment.

In Exasol, BucketFS is the only accessible filesystem for UDFs and it operates in a chrooted environment. As such, paths inside UDFs differ from those on the host system or exposed via the BucketFS web interface. This method abstracts away those differences and provides the correct UDF-local path.

Returns:

the absolute path to the bucket as seen inside the UDF

getPathInUdf

default String getPathInUdf(String fileInBucketFs)

Return the UDF-visible path to a specific file within this bucket in BucketFS.

This method ensures that the path to the given file is correctly formed in the context of a UDF environment, taking into account the chrooted nature of BucketFS.

This is useful for referencing files inside a bucket from UDFs, where the apparent file paths are isolated from the underlying host filesystem.

Parameters:

fileInBucketFs - the relative path or name of the file inside the bucket

Returns:

the absolute path to the file as seen inside the UDF