de.binfalse.bfutils

Class FileRetriever

java.lang.Object

de.binfalse.bfutils.FileRetriever

public class FileRetriever
extends Object

Class FileRetriever to retrieve files from disk or from web. TODO: JDOC

Author:

Martin Scharm

Field Summary

Fields

Modifier and Type	Field and Description
static File	CACHE_DIR The cache dir.
static boolean	FIND_LOCAL Are we allowed to search for local files?.
static boolean	FIND_REMOTE Are we allowed to search for files on the Internet?.

Constructor Summary

Constructors

Constructor and Description
FileRetriever()

Method Summary

Modifier and Type	Method and Description
protected static String	copy(URI from, File to, boolean local) Copy a file.
protected static String	download(URI from, File to, boolean downloadAnyway, Map<String,String> addidionalHeaders) Download a file from a remote location..
static String	getFile(URI file, File dest) Retrieves a file from an URI.
static String	getFile(URI file, File dest, Map<String,String> additionalDownloadHeaders) Retrieves a file from an URI.
static URI	getUri(String href, URI base) Compute an URI location.
static boolean	setUpCache(File directory) Sets the up caching.

Methods inherited from class java.lang.Object

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

Field Detail

CACHE_DIR

public static File CACHE_DIR

The cache dir.

FIND_LOCAL

public static boolean FIND_LOCAL

Are we allowed to search for local files?.

FIND_REMOTE

public static boolean FIND_REMOTE

Are we allowed to search for files on the Internet?.

Constructor Detail

FileRetriever

public FileRetriever()

Method Detail

setUpCache

public static boolean setUpCache(File directory)
                          throws IOException

Sets the up caching. Pass null as an argument to disable caching.

Parameters:

directory - the directory to write to

Returns:

true, if successfully configured caching

Throws:

IOException

getUri

public static URI getUri(String href,
                         URI base)
                  throws URISyntaxException,
                         IOException

Compute an URI location. If href is relative we try to resolve it using base

Parameters:

href - the href

base - the base URI

Returns:

the URI

Throws:

URISyntaxException - the URI syntax exception

IOException - the IO exception

copy

protected static String copy(URI from,
                             File to,
                             boolean local)
                      throws IOException

Copy a file. Will throw an exception if FIND_LOCAL is false.

Parameters:

from - the origin

to - the destination

Throws:

IOException - the IO exception

download

protected static String download(URI from,
                                 File to,
                                 boolean downloadAnyway,
                                 Map<String,String> addidionalHeaders)
                          throws IOException

Download a file from a remote location.. Will throw an exception if FIND_REMOTE is false.

Parameters:

from - the origin

to - the destination

Throws:

IOException - the IO exception

getFile

public static String getFile(URI file,
                             File dest)
                      throws IOException,
                             URISyntaxException

Retrieves a file from an URI.

Parameters:

file - the URI to the file

dest - the destination to write to

Throws:

IOException - Signals that an I/O exception has occurred.

URISyntaxException - thrown if file or base have a strange format

getFile

public static String getFile(URI file,
                             File dest,
                             Map<String,String> additionalDownloadHeaders)
                      throws IOException,
                             URISyntaxException

Retrieves a file from an URI. You may supply additional headers in case the file needs to be downloaded from the internet and you need to negotiate the content, for example. Just add a map such as:

 
 {
        @code Map<String, String> addHeaders = new HashMap<String, String> ();
        addHeaders.put ("Accept", "text/html");
        FileRetriever.getFile (new URI ("URL"), DESTFILE, addHeaders);
 }
 

Parameters:

file - the URI to the file

dest - the destination to write to

additionalDownloadHeaders - the additional headers to be supplied in case of a download

Returns:

the file

Throws:

IOException - Signals that an I/O exception has occurred.

URISyntaxException - thrown if file or base have a strange format