### Question:
MahoutRecommender implements Recommender { public void IRState(String taskName) { String itemmodelsPath = RecommendConfig.class.getResource("/").getPath() + "itemmodels.csv"; HadoopUtil.download(taskName, itemmodelsPath, false); try { DataModel fileDataModel = new FileDataModel(new File(itemmodelsPath)); RecommenderIRStatsEvaluator irStatsEvaluator = new GenericRecommenderIRStatsEvaluator(); IRStatistics irStatistics = irStatsEvaluator.evaluate(new RecommenderBuilder() { @Override public org.apache.mahout.cf.taste.recommender.Recommender buildRecommender(final DataModel dataModel) throws TasteException { UserSimilarity userSimilarity = new PearsonCorrelationSimilarity(dataModel); UserNeighborhood userNeighborhood = new NearestNUserNeighborhood(5, userSimilarity, dataModel); return new GenericUserBasedRecommender(dataModel, userNeighborhood, userSimilarity); } }, new DataModelBuilder() { @Override public DataModel buildDataModel(final FastByIDMap<PreferenceArray> fastByIDMap) { return new GenericDataModel(fastByIDMap); } }, fileDataModel, null, 5, GenericRecommenderIRStatsEvaluator.CHOOSE_THRESHOLD, 1.0); System.out.println("查准率:" + irStatistics.getPrecision()); System.out.println("查全率:" + irStatistics.getRecall()); } catch (TasteException | IOException e) { e.printStackTrace(); } }  @Override long[] recommend(String taskName, int userID); @Override long[] recommend(final String taskName, final Float threshold, final int userID); @Override long[] recommend(String taskName, String similarity, String neighborhood, Float threshold, int userID); void buildRecommend(String taskName); void evaluate(String taskName); void IRState(String taskName);  }### Answer:
@Test public void IRState() { recommender.IRState("mmsnsarticle"); }