/**
* This method construct hashTag graph to calculate the degree
*
* @param tweetList
* @return
*/
private HashMap<String, Set<String>> getHashTagGraph(List<Tweet> tweetList) {
HashMap<String, Set<String>> hashTagGraph = new HashMap<String, Set<String>>(20);
// Iterate through each tweet's hastags to construct the graph
for (Tweet tweet : tweetList) {
Set<String> hashTags = tweet.getHashTags();
if (hashTags.size() >= 2) {
for (String hashTag : hashTags) {
for (String innerHashTag : hashTags) {
if (!hashTag.equalsIgnoreCase(innerHashTag)) {
Set<String> entries = hashTagGraph.get(hashTag);
if (entries == null) {
entries = new HashSet<String>();
}
entries.add(innerHashTag);
hashTagGraph.put(hashTag, entries);
}
}
}
}
}
return hashTagGraph;
}
