io.cdap.wrangler.service.explorer

Class Explorer

java.lang.Object

io.cdap.wrangler.service.explorer.Explorer

public final class Explorer
extends Object

File system explorer.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEVICE
static String	UNKNOWN

Constructor Summary

Constructors

Constructor and Description
Explorer(DatasetProvider provider)

Method Summary

Modifier and Type	Method and Description
Map<String,Object>	browse(String path, boolean hidden) Explores the path provided on the filesystem.
org.apache.twill.filesystem.Location	getLocation(String path) Trick, to extract the URI for a location.
BoundedLineInputStream	read(String path, Charset encoding, int lines) This methods provides an efficiently way to read a file from the file system specified by the Location..
byte[]	read(String path, int size) Reads the 'size' bytes from the file.
BoundedLineInputStream	read(String path, String encoding, int lines)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEVICE

public static final String DEVICE

See Also:

Constant Field Values

UNKNOWN

public static final String UNKNOWN

See Also:

Constant Field Values

Constructor Detail

Explorer

public Explorer(DatasetProvider provider)

Method Detail

browse

public Map<String,Object> browse(String path,
                                 boolean hidden)
                          throws ExplorerException

Explores the path provided on the filesystem.

Parameters:

path - to be explored.

Returns:

Information about all the files/directories in the path.

Throws:

ExplorerException - thrown when there is issue browsing directory.

read

public BoundedLineInputStream read(String path,
                                   Charset encoding,
                                   int lines)
                            throws ExplorerException,
                                   IOException

This methods provides an efficiently way to read a file from the file system specified by the Location.. It uses a bounded line stream that limits the lines being read from the BufferedInputStream.

Parameters:

path - Specifies the path to file to be read. Assumes the file exists at the path specified.

encoding - Specifies the encoding of the file.

lines - Number of lines to be read from the file.

Returns:

BoundedLineInputStream

Throws:

ExplorerException

IOException

read

public BoundedLineInputStream read(String path,
                                   String encoding,
                                   int lines)
                            throws ExplorerException,
                                   IOException

Throws:

ExplorerException

IOException

read

public byte[] read(String path,
                   int size)
            throws ExplorerException,
                   IOException

Reads the 'size' bytes from the file.

Parameters:

path - to the file being read.

size - specifies the bytes to be read.

Returns:

bytes read.

Throws:

ExplorerException

IOException

getLocation

public org.apache.twill.filesystem.Location getLocation(String path)
                                                 throws ExplorerException

Trick, to extract the URI for a location.

Parameters:

path - to a Dataset.

Returns:

Location

Throws:

URISyntaxException - issue constructing the URI.

ExplorerException