com.sun.syndication.io.FeedException: Invalid rss_2.0 feed, missing channel link
com.sun.syndication.io.impl.RSS090Generator.checkNotNullAndLength(RSS090Generator.java:128)
com.sun.syndication.io.impl.RSS092Generator.checkChannelConstraints(RSS092Generator.java:139)
com.sun.syndication.io.impl.RSS090Generator.addChannel(RSS090Generator.java:97)
com.sun.syndication.io.impl.RSS091UserlandGenerator.addChannel(RSS091UserlandGenerator.java:77)
com.sun.syndication.io.impl.RSS091UserlandGenerator.populateFeed(RSS091UserlandGenerator.java:73)
com.sun.syndication.io.impl.RSS090Generator.generate(RSS090Generator.java:56)
com.sun.syndication.io.WireFeedOutput.outputJDom(WireFeedOutput.java:271)
com.sun.syndication.io.WireFeedOutput.outputString(WireFeedOutput.java:118)
com.sun.syndication.io.WireFeedOutput.outputString(WireFeedOutput.java:97)
com.sun.syndication.io.SyndFeedOutput.outputString(SyndFeedOutput.java:61)