it.unimi.dsi.parser.callback

Class LinkExtractor

java.lang.Object

it.unimi.dsi.parser.callback.DefaultCallback

it.unimi.dsi.parser.callback.LinkExtractor

All Implemented Interfaces:

Callback

public class LinkExtractor
extends DefaultCallback

A callback extracting links.

This callbacks extracts links existing in the web page. The links are then accessible in urls (a set of Strings). Note that we guarantee that the iteration order in the set is exactly the order in which links have been met (albeit copies appear just once).

Field Summary

Fields

Modifier and Type	Field and Description
Set<String>	urls The URLs resulting from the parsing process.

Fields inherited from interface it.unimi.dsi.parser.callback.Callback

EMPTY_CALLBACK_ARRAY

Constructor Summary

Constructors

Constructor and Description
LinkExtractor()

Method Summary

Methods

Modifier and Type	Method and Description
String	base() Returns the URL specified by the BASE element.
void	configure(BulletParser parser) Configure the parser to parse elements and certain attributes.
String	metaLocation() Returns the URL specified by META HTTP-EQUIV elements of location type.
String	metaRefresh() Returns the URL specified by META HTTP-EQUIV elements of refresh type.
void	startDocument() Receive notification of the beginning of the document.
boolean	startElement(Element element, Map<Attribute,MutableString> attrMap) Receive notification of the start of an element.

Methods inherited from class it.unimi.dsi.parser.callback.DefaultCallback

cdata, characters, endDocument, endElement, getInstance

Methods inherited from class java.lang.Object

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

Field Detail

urls

public final Set<String> urls

The URLs resulting from the parsing process.

Constructor Detail

LinkExtractor

public LinkExtractor()

Method Detail

configure

public void configure(BulletParser parser)

Configure the parser to parse elements and certain attributes.

The required attributes are SRC , HREF , HTTP-EQUIV , and CONTENT .

Specified by:

configure in interface Callback

Overrides:

configure in class DefaultCallback

startDocument

public void startDocument()

Description copied from interface: Callback

Receive notification of the beginning of the document.

The callback must use this method to reset its internal state so that it can be resued. It must be safe to invoke this method several times.

Specified by:

startDocument in interface Callback

Overrides:

startDocument in class DefaultCallback

startElement

public boolean startElement(Element element,
                   Map<Attribute,MutableString> attrMap)

Description copied from interface: Callback

Receive notification of the start of an element.

For simple elements, this is the only notification that the callback will ever receive.

Specified by:

startElement in interface Callback

Overrides:

startElement in class DefaultCallback

Parameters:

element - the element whose opening tag was found.

attrMap - a map from Attributes to MutableStrings.

Returns:

true to keep the parser parsing, false to stop it.

metaLocation

public String metaLocation()

Returns the URL specified by META HTTP-EQUIV elements of location type. More precisely, this method returns a non- null result iff there is at least one META HTTP-EQUIV element specifying a location URL (if there is more than one, we keep the first one).

Returns:

the first URL specified by a META HTTP-EQUIV elements of location type, or null.

base

public String base()

Returns the URL specified by the BASE element. More precisely, this method returns a non- null result iff there is at least one BASE element specifying a derelativisation URL (if there is more than one, we keep the first one).

Returns:

the first URL specified by a BASE element, or null.

metaRefresh

public String metaRefresh()

Returns the URL specified by META HTTP-EQUIV elements of refresh type. More precisely, this method returns a non- null result iff there is at least one META HTTP-EQUIV element specifying a refresh URL (if there is more than one, we keep the first one).

Returns:

the first URL specified by a META HTTP-EQUIV elements of refresh type, or null.