今天整合SSlopeOneRecommender推荐算法，结果显示找不到SlopeOneRecommender类，上网查资料得知此类的全类名为：org.apache.mahout.cf.taste.impl.recommender.slopeone.SlopeOneRecommender，所以去查看jar包，发现没有。查看src包也没有这个类的源码，之后查看官网信息，才知道这个算法在0.9版本上被移除了。如果想用的话需要0.8版本
1 February 2014 - Apache Mahout 0.9 released
Apache Mahout has reached version 0.9. All developers are encouraged to begin using version 0.9. Highlights include:
New and improved Mahout website based on Apache CMS - MAHOUT-1245
Early implementation of a Multi Layer Perceptron (MLP) classifier - MAHOUT-1265
Scala DSL Bindings for Mahout Math Linear Algebra. See this blogpost and MAHOUT-1297
Recommenders as Search. See [https://github.com/pferrel/solr-recommender] and MAHOUT-1288
Support for easy functional Matrix views and derivatives - MAHOUT-1300
JSON output format for ClusterDumper - MAHOUT-1343
Enabled randomised testing for all Mahout modules using Carrot RandomizedRunner - MAHOUT-1345
Online Algorithm for computing accurate Quantiles using 1-dimensional Clustering - See this pdf and MAHOUT-1361
Upgrade to Lucene 4.6.1 - MAHOUT-1364
Changes in 0.9 are detailed in the release notes.
The following algorithms that were marked deprecated in 0.8 have been removed in 0.9:
Switched LDA implementation from Gibbs Sampling to Collapsed Variational Bayes
Meanshift - removed due to lack of actual usage and support
MinHash - removed due to lack of actual usage and support
Winnow - removed due to lack of actual usage and support
Perceptron - removed due to lack of actual usage and support
Slope One - removed due to lack of actual usage
Distributed Pseudo recommender - removed due to lack of actual usage
TreeClusteringRecommender - removed due to lack of actual usage
