prajna.io

Class RssReader

java.lang.Object

prajna.io.RssReader

All Implemented Interfaces:

FormatReader<RssItem>

public class RssReader
extends java.lang.Object
implements FormatReader<RssItem>

Reader which reads standard RSS information from a URL.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
RssReader() Create a new RssReader.
RssReader(java.lang.String urlStr) Create a new RssReader from the given URL, specified by a string
RssReader(java.net.URL url) Create a new RssReader from the given URL

Method Summary

Methods

Modifier and Type	Method and Description
boolean	canRead() Return whether this reader is in a state where it can attempt to read data.
void	close() Close this reader.
java.lang.String	getFilters() Get the filters for this reader.
java.lang.String	getSource() Get the source for this reader
boolean	hasMoreData() Returns whether the reader has more data to read.
java.util.List<RssItem>	readData() Read data from the RssReader.
void	setDelay(long seconds) Set the time the RSS feed must wait before checking the website for new data.
void	setFilters(java.lang.String filters) Set the filters for this reader.
void	setSource(java.lang.String source) Set the source for this Rss Reader.

Methods inherited from class java.lang.Object

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

Constructor Detail

RssReader

public RssReader()

Create a new RssReader. The reader will need an RSS source set using the setSource() method

RssReader

public RssReader(java.lang.String urlStr)
          throws java.io.IOException,
                 org.xml.sax.SAXException

Create a new RssReader from the given URL, specified by a string

Parameters:

urlStr - the RSS feed URL string

Throws:

java.io.IOException - if there is a problem opening a connection to the stream

org.xml.sax.SAXException - if there is a problem reading the data from the stream

RssReader

public RssReader(java.net.URL url)
          throws java.io.IOException,
                 org.xml.sax.SAXException

Create a new RssReader from the given URL

Parameters:

url - the RSS feed URL

Throws:

java.io.IOException - if there is a problem opening a connection to the stream

org.xml.sax.SAXException - if there is a problem reading the data from the stream

Method Detail

canRead

public boolean canRead()

Return whether this reader is in a state where it can attempt to read data. This call checks to see if the reader can open an input stream to the RSS URL.

Specified by:

canRead in interface FormatReader<RssItem>

Returns:

true if it can read data, false otherwise

close

public void close()

Close this reader.

Specified by:

close in interface FormatReader<RssItem>

getFilters

public java.lang.String getFilters()

Get the filters for this reader. Currently only returns null, as the setFilters method does nothing

Specified by:

getFilters in interface FormatReader<RssItem>

Returns:

null

getSource

public java.lang.String getSource()

Get the source for this reader

Specified by:

getSource in interface FormatReader<RssItem>

Returns:

the source for this reader

hasMoreData

public boolean hasMoreData()

Returns whether the reader has more data to read. This method checks the available items on the RssFeed to see if any are more recent than the last time this RssReader read data. To prevent overloading the RSS site, this method will return false if it has been less than one hour since the last RSS check.

Specified by:

hasMoreData in interface FormatReader<RssItem>

Returns:

true if the reader has more data to read, false otherwise

readData

public java.util.List<RssItem> readData()

Read data from the RssReader. This method retrieves any new RssItems from the feed.

Specified by:

readData in interface FormatReader<RssItem>

Returns:

the list of new RssItems

setDelay

public void setDelay(long seconds)

Set the time the RSS feed must wait before checking the website for new data. The default value is one hour. This value should be set to avoid overloading the RSS site with queries.

Parameters:

seconds - the number of seconds to delay.

setFilters

public void setFilters(java.lang.String filters)

Set the filters for this reader. Ignored

Specified by:

setFilters in interface FormatReader<RssItem>

Parameters:

filters -

setSource

public void setSource(java.lang.String source)

Set the source for this Rss Reader.

Specified by:

setSource in interface FormatReader<RssItem>

Parameters:

source - the source URL for the RSS feed.