recommend system study
CosineSimilarAlgorithm:余弦获取文章相似性http://www.chepoo.com/cosine-similarity-java-implementation.html
SimpleSummariserAlgorithm:文本摘要实现http://www.chepoo.com/article-summarization-implementation.html
TfIdfAlgorithm： tf-idf算法实现 http://www.chepoo.com/tf-idf-java-implementation.html
WordTrie：单词Trie树 http://www.chepoo.com/trie-tree-java-implementation.html
SpellCorrect:英文拼写检查http://www.chepoo.com/english-spell-checker-java-implementation.html