org.dice_research.squirrel.fetcher.manage

Class SimpleOrderedFetcherManager

java.lang.Object

org.dice_research.squirrel.fetcher.manage.SimpleOrderedFetcherManager

All Implemented Interfaces:

Closeable, AutoCloseable, Fetcher

public class SimpleOrderedFetcherManager
extends Object
implements Fetcher

A very simple manager for Fetcher instances that is based on the order of the given fetchers. If the manager has got the fetchers A and B, it will first try to fetch data from the given URI using A. If this is successful (i.e., A.fetch(uri) != null) the result of Fetcher A is returned. Only if A returns null Fetcher B is used.

Author:

Michael Röder (michael.roeder@uni-paderborn.de)

Field Summary

Fields

Modifier and Type	Field and Description
static String	FETCHER
private Fetcher[]	fetchers
private static org.slf4j.Logger	LOGGER

Constructor Summary

Constructors

Constructor and Description
SimpleOrderedFetcherManager(Fetcher... fetchers)

Method Summary

Modifier and Type	Method and Description
void	close()
File	fetch(org.dice_research.squirrel.data.uri.CrawleableUri uri, Delayer delayer) Fetches a stream of data from the given URI by following the delay implemented by the given Delayer, stores it and returns a File object pointing to the stored data.
Fetcher[]	getFetchers()
void	setFetchers(Fetcher... fetchers)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.dice_research.squirrel.fetcher.Fetcher

fetch

Field Detail

LOGGER

private static final org.slf4j.Logger LOGGER

FETCHER

public static final String FETCHER

See Also:

Constant Field Values

fetchers

private Fetcher[] fetchers

Constructor Detail

SimpleOrderedFetcherManager

public SimpleOrderedFetcherManager(Fetcher... fetchers)

Method Detail

setFetchers

public void setFetchers(Fetcher... fetchers)

getFetchers

public Fetcher[] getFetchers()

fetch

public File fetch(org.dice_research.squirrel.data.uri.CrawleableUri uri,
                  Delayer delayer)

Description copied from interface: Fetcher

Fetches a stream of data from the given URI by following the delay implemented by the given Delayer, stores it and returns a File object pointing to the stored data. If an error occurs, null is returned.

Specified by:

fetch in interface Fetcher

Parameters:

uri - The URI from which data should be fetched.

Returns:

A File object pointing to the downloaded data or null if an error occurred.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException