uk.ac.starlink.util

Class TemporaryFileDataSource

java.lang.Object

uk.ac.starlink.util.DataSource

uk.ac.starlink.util.FileDataSource

uk.ac.starlink.util.TemporaryFileDataSource

public class TemporaryFileDataSource
extends FileDataSource

A DataSource which stores its data in a temporary file. This can be used to represent data which is only available to read once from an intput stream. The stream is read when this source is constructed, and cached in a temporary file. The temporary file is removed when this object becomes unreachable or when the VM is terminated normally.

Author:

Mark Taylor (Starlink), Peter W. Draper (Starlink)

Field Summary

Fields inherited from class uk.ac.starlink.util.DataSource

DEFAULT_INTRO_LIMIT, MARK_WORKAROUND_PROPERTY

Constructor Summary

Constructors

Constructor and Description
TemporaryFileDataSource(InputStream baseStream, String name) Constructs a new DataSource by reading the contents of an input stream.
TemporaryFileDataSource(InputStream baseStream, String name, String prefix, String suffix, File directory) Constructs a new DataSource by reading the contents of an input stream.

Method Summary

Modifier and Type	Method and Description
URL	getURL() Returns null, since the data is not represented by a persistent object.

Methods inherited from class uk.ac.starlink.util.FileDataSource

getFile, getRawInputStream, getRawLength

Methods inherited from class uk.ac.starlink.util.DataSource

close, forceCompression, getCompression, getHybridInputStream, getInputStream, getInputStream, getIntro, getIntroLimit, getLength, getMarkWorkaround, getName, getPosition, getSystemId, makeDataSource, makeDataSource, makeDataSource, setCompression, setIntroLimit, setMarkWorkaround, setName, setPosition, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

TemporaryFileDataSource

public TemporaryFileDataSource(InputStream baseStream,
                               String name)
                        throws IOException

Constructs a new DataSource by reading the contents of an input stream. The name of the source is also supplied; it does not take the name (or URL) of the file, since that does not represent a persistent object.

Parameters:

baseStream - the stream which supplies this source's data

name - the name of the source

Throws:

IOException

TemporaryFileDataSource

public TemporaryFileDataSource(InputStream baseStream,
                               String name,
                               String prefix,
                               String suffix,
                               File directory)
                        throws IOException

Constructs a new DataSource by reading the contents of an input stream. The name of the source is also supplied; it does not take the name (or URL) of the file, since that does not represent a persistent object. Using this constructor you may also supply the prefix, suffix and directory used for the temporary file see File.createTempFile(String,String,File).

Parameters:

baseStream - the stream which supplies this source's data

name - the name of the source

prefix - the prefix string to be used in generating the file's name; must be at least three characters long

suffix - the suffix string to be used in generating the file's name; may be null, in which case the suffix ".tmp" will be used

directory - the directory in which the file is to be created, or null if the default temporary-file directory is to be used

Throws:

IOException

Method Detail

getURL

public URL getURL()

Returns null, since the data is not represented by a persistent object.

Overrides:

getURL in class FileDataSource

Returns:

a URL corresponding to this source, or null