org.htmlparser.beans

Class FilterBean

Implemented Interfaces:
Serializable

public class FilterBean
extends Object
implements Serializable

Extract nodes from a URL using a filter.
 
     FilterBean fb = new FilterBean ("http://cbc.ca");
     fb.setFilters (new NodeFilter[] { new TagNameFilter ("META") });
     fb.setURL ("http://cbc.ca");
     System.out.println (fb.getNodes ().toHtml ());
 
 

Field Summary

static String
PROP_CONNECTION_PROPERTY
Property name in event where the connection changes.
static String
PROP_NODES_PROPERTY
Property name in event where the URL contents changes.
static String
PROP_TEXT_PROPERTY
Property name in event where the URL contents changes.
static String
PROP_URL_PROPERTY
Property name in event where the URL changes.
protected NodeFilter[]
mFilters
The filter set.
protected NodeList
mNodes
The nodes extracted from the URL.
protected Parser
mParser
The parser used to filter.
protected PropertyChangeSupport
mPropertySupport
Bound property support.
protected boolean
mRecursive
The recursion behaviour for elements of the filter array.

Constructor Summary

FilterBean()
Create a FilterBean object.

Method Summary

void
addPropertyChangeListener(PropertyChangeListener listener)
Add a PropertyChangeListener to the listener list.
protected NodeList
applyFilters()
Apply each of the filters.
URLConnection
getConnection()
Get the current connection.
NodeFilter[]
getFilters()
Get the current filter set.
NodeList
getNodes()
Return the nodes of the URL matching the filter.
Parser
getParser()
Get the parser used to fetch nodes.
boolean
getRecursive()
Get the current recursion behaviour.
String
getText()
Convenience method to apply a StringBean to the filter results.
String
getURL()
Get the current URL.
static void
main(String[] args)
Unit test.
void
removePropertyChangeListener(PropertyChangeListener listener)
Remove a PropertyChangeListener from the listener list.
void
setConnection(URLConnection connection)
Set the parser's connection.
void
setFilters(NodeFilter[] filters)
Set the filters for the bean.
protected void
setNodes()
Fetch the URL contents and filter it.
void
setParser(Parser parser)
Set the parser for the bean.
void
setRecursive(boolean recursive)
Set the recursion behaviour.
void
setURL(String url)
Set the URL to extract strings from.
protected void
updateNodes(NodeList nodes)
Assign the Nodes property, firing the property change.

Field Details

PROP_CONNECTION_PROPERTY

public static final String PROP_CONNECTION_PROPERTY
Property name in event where the connection changes.

PROP_NODES_PROPERTY

public static final String PROP_NODES_PROPERTY
Property name in event where the URL contents changes.

PROP_TEXT_PROPERTY

public static final String PROP_TEXT_PROPERTY
Property name in event where the URL contents changes.

PROP_URL_PROPERTY

public static final String PROP_URL_PROPERTY
Property name in event where the URL changes.

mFilters

protected NodeFilter[] mFilters
The filter set.

mNodes

protected NodeList mNodes
The nodes extracted from the URL.

mParser

protected Parser mParser
The parser used to filter.

mPropertySupport

protected PropertyChangeSupport mPropertySupport
Bound property support.

mRecursive

protected boolean mRecursive
The recursion behaviour for elements of the filter array. If true the filters are applied recursively.

Constructor Details

FilterBean

public FilterBean()
Create a FilterBean object.

Method Details

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)
Add a PropertyChangeListener to the listener list. The listener is registered for all properties.
Parameters:
listener - The PropertyChangeListener to be added.

applyFilters

protected NodeList applyFilters()
            throws ParserException
Apply each of the filters. The first filter is applied to the output of the parser. Subsequent filters are applied to the output of the prior filter.
Returns:
A list of nodes passed through all filters. If there are no filters, returns the entire page.
Throws:
ParserException - If an encoding change occurs or there is some other problem.

getConnection

public URLConnection getConnection()
Get the current connection.
Returns:
The connection that the parser has or null if it hasn't been set or the parser hasn't been constructed yet.

getFilters

public NodeFilter[] getFilters()
Get the current filter set.
Returns:
The current filters.

getNodes

public NodeList getNodes()
Return the nodes of the URL matching the filter. This is the primary output of the bean.
Returns:
The nodes from the URL matching the current filter.

getParser

public Parser getParser()
Get the parser used to fetch nodes.
Returns:
The parser used by the bean.

getRecursive

public boolean getRecursive()
Get the current recursion behaviour.
Returns:
The recursion (applies to children, children's children, etc) behavior currently being used.

getText

public String getText()
Convenience method to apply a StringBean to the filter results. This may yield duplicate or multiple text elements if the node list contains nodes from two or more levels in the same nested tag heirarchy, but if the node list contains only one tag, it provides access to the text within the node.
Returns:
The textual contents of the nodes that pass through the filter set, as collected by the StringBean.

getURL

public String getURL()
Get the current URL.
Returns:
The URL from which text has been extracted, or null if this property has not been set yet.

main

public static void main(String[] args)
Unit test.
Parameters:
args - Pass arg[0] as the URL to process, and optionally a node name for filtering.

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)
Remove a PropertyChangeListener from the listener list. This removes a registered PropertyChangeListener.
Parameters:
listener - The PropertyChangeListener to be removed.

setConnection

public void setConnection(URLConnection connection)
Set the parser's connection. The text from the URL will be fetched, which may be expensive, so this property should be set last.
Parameters:
connection - New value of property Connection.

setFilters

public void setFilters(NodeFilter[] filters)
Set the filters for the bean. If the parser has been set, it is reset and the nodes are refetched with the new filters.
Parameters:
filters - The filter set to use.

setNodes

protected void setNodes()
Fetch the URL contents and filter it. Only do work if there is a valid parser with it's URL set.

setParser

public void setParser(Parser parser)
Set the parser for the bean. The parser is used immediately to fetch the nodes, which for a null filter means all the nodes
Parameters:
parser - The parser to use.

setRecursive

public void setRecursive(boolean recursive)
Set the recursion behaviour.
Parameters:
recursive - If true the extractAllNodesThatMatch() call is performed recursively.

setURL

public void setURL(String url)
Set the URL to extract strings from. The text from the URL will be fetched, which may be expensive, so this property should be set last.
Parameters:
url - The URL that text should be fetched from.

updateNodes

protected void updateNodes(NodeList nodes)
Assign the Nodes property, firing the property change.
Parameters:
nodes - The new value of the Nodes property.

HTML Parser is an open source library released under LGPL. SourceForge.net