RSS Reader Java Library

Feed filters allow you to transform or clean the raw InputStream of a feed before it is parsed. This is useful for removing invalid XML characters or applying custom preprocessing logic. To use a filter, implement the FeedFilter interface and pass it to addFeedFilter().

RssReader reader = new RssReader();
List<Item> items = reader.addFeedFilter(new InvalidXmlCharacterFilter())
                         .read(URL)
                         .toList();

To use RSS Reader in your Java project, add the following dependency to your build configuration. Note that since version 3.0.0, the group ID is com.apptasticsoftware.

Maven Add the dependency to your pom.xml:

Gradle Add the implementation line to your build.gradle:

<!-- Maven -->
<dependency>
    <groupId>com.apptasticsoftware</groupId>
    <artifactId>rssreader</artifactId>
    <version>3.12.0</version>
</dependency>

<!-- Gradle -->
dependencies {
    implementation 'com.apptasticsoftware:rssreader:3.12.0'
}

You can ingest feed data from local files using either an InputStream or a file URI.

Using InputStream

InputStream inputStream = new FileInputStream("/path/to/file");
List<Item> items = new RssReader().read(inputStream).toList();

Using file URI

List<Item> items = new RssReader().read("file:/path/to/file").toList();

// Using InputStream
InputStream inputStream = new FileInputStream("/path/to/file");
List<Item> items = new RssReader().read(inputStream).toList();

// Using file URI
List<Item> items = new RssReader().read("file:/path/to/file").toList();

The read(List<String> urls) method allows you to process multiple feeds into a single stream. You can use ItemComparator to control the sort order of the resulting items.

Available Comparators:

• ItemComparator.oldestPublishedItemFirst(): Sorts by publication date (ascending).
• ItemComparator.newestUpdatedItemFirst(): Sorts by updated date (descending).
• ItemComparator.oldestUpdatedItemFirst(): Sorts by updated date (ascending).

List<String> urls = List.of(URL1, URL2, URL3, URL4, URL5); 
new RssReader().read(urls)
               .sorted(ItemComparator.oldestPublishedItemFirst())
               .map(Item::getTitle)
               .forEach(System.out::println);

Use the RssReader class to read feeds from a URL. The read(URL) method returns a Stream<Item> which can be converted to a list or filtered.

RssReader rssReader = new RssReader();
List<Item> items = rssReader.read(URL)
                            .toList();

For feeds containing podcast-specific metadata, use the ItunesRssReader class. This specialized reader extracts data from iTunes-specific tags and attributes into ItunesItem objects.

List<ItunesItem> items = new ItunesRssReader().read(URL)
                                              .toList();

You can extend the standard Item object by mapping custom XML tags or attributes to existing setter methods using addItemExtension(String tagName, Consumer<Item> setter).

List<Item> items = new RssReader()
             .addItemExtension("dc:creator", Item::setAuthor)
             .addItemExtension("dc:date", Item::setPubDate)
             .read("https://lwn.net/headlines/rss")
             .toList();