推荐系统

Question

我正在尝试实现一个基于mahout的推荐系统。我无法在jsf页面上显示结果。

@ManagedBean（name="similarAvaluerecommender"）@ViewScoped

公共类SimilarValueRecommender实现Serializable{私人列表推荐项目；

@PostConstruct
public void init() {
    this.recommendedItems = new ArrayList<>();

    DataModel dm;
    try {
        dm = new FileDataModel(new File("Dataset/userdata.csv"));
    //ItemSimilarity sim = new LogLikelihoodSimilarity(dm);
    TanimotoCoefficientSimilarity sim = new TanimotoCoefficientSimilarity(dm);
    GenericItemBasedRecommender recommender = new GenericItemBasedRecommender(dm, sim);
    int x=1;
        for(LongPrimitiveIterator items = dm.getItemIDs(); items.hasNext();) {
            long itemId = items.nextLong();
            List<RecommendedItem>recommendedItems1 = recommender.mostSimilarItems(itemId, 10);
            this.recommendedItems.addAll(recommendedItems1);
            x++;
        }
    } catch (TasteException ex) {
        Logger.getLogger(SimilarValueRecommender.class.getName()).log(Level.SEVERE, null, ex);
    }
    catch (IOException ex) {
        Logger.getLogger(SimilarValueRecommender.class.getName()).log(Level.SEVERE, null, ex);
    }
}
//getter and setter...
 public List<RecommendedItem> getRecommendedItems(){
     return recommendedItems;
 }
 public void setList(List<RecommendedItem> recommendedItems) {
     this.recommendedItems=recommendedItems;
 }

}

我想以表格的形式在jsf页面上显示此页面的结果。这是视图

<ui:composition template="WEB-INF/commonlayout.xhtml">
        <ui:define name="content">
            <h:form>
                hi
                <h:dataTable id="similarvaluestable" value="#{similarvaluerecommender.recommendedItems}" var="recommendedItem">
                <h:column>
                #{recommendedItem.itemID}
        </h:column>

                </h:form>
             </ui:define>  
    </ui:composition>
</h:body>
 </html>

Answer 1

执行以下操作：

• 在托管bean中声明一个List<RecommendedItem> recommendations属性
• 为此属性定义getter和setter方法。不要在这些方法中包含任何业务逻辑
• 在@PostConstruct方法中加载数据，并将其存储到recommendations属性中
• 在视图中显示来自recommendations属性的数据

代码中：

@ManagedBean("similarValueRecommender")
@ViewScoped
public class SimilarValueRecommender implements Serializable {
    List<RecommendedItem> recommendations;
    @PostConstruct
    public void init() {
        this.recommendations = new ArrayList<RecommendedItem>();
        //taken from your current code
        //seems like this is the code to load recommendations
        DataModel dm = new AlphaItemFileDataModel(new File("Dataset/userdata.csv"));
        //ItemSimilarity sim = new LogLikelihoodSimilarity(dm);
        TanimotoCoefficientSimilarity sim = new TanimotoCoefficientSimilarity(dm);
        GenericItemBasedRecommender recommender = new GenericItemBasedRecommender(dm, sim);
        int x=1;
        for(LongPrimitiveIterator items = dm.getItemIDs(); items.hasNext();) {
            long itemId = items.nextLong();
            List<RecommendedItem>recommendations = recommender.mostSimilarItems(itemId, 10);
            /*
            for(RecommendedItem recommendation : recommendations) {
                similaritemID=recommendation.getItemID();
                System.out.println(itemId + "," + recommendation.getItemID() + "," + recommendation.getValue());
            }
            */
            this.recommendations.addAll(recommendations);
            x++;
            //if(x>10) System.exit(1);
        }
    }
    //getter and setter...
}

在您看来：

<h:dataTable value="#{similarValueRecommender.recommendations}" var="recommendation">
    <h:column>
        #{recommendation.text}
    </h:column>
</h:dataTable>