eclipsemavenmahoutmahout-recommender

maven in eclipse giving filenotfound exception for data.csv file


I am trying a simple movie recommender by referring a short video here- https://www.youtube.com/watch?v=63k560Livmg . What I am trying diff is instead of console , I want recommendations to be displayed on browser so I am using servlets. But the problem is when i input a value(user id ) in my form, blank screen is shown . Please help what I am doing wrong. Dataset from here- https://mahout.apache.org/users/recommender/userbased-5-minutes.html. Refer screenshot attached for web.xml and hierarchy.

index.jsp

    <html>
    <body>
     <h2>Hello World!</h2>
     <form action="demo" method="post">  
     loginID:<input type="text" name="name"/><br/>
     <input type="submit" value="login"/> 

    </form>
    </body>
    </html>

demo.java- servlet for collecting user value and display result.

  package com.issac;

  import java.io.IOException;
  import java.io.PrintWriter;
  import java.util.ArrayList;
   import java.util.List;

  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;


import org.apache.mahout.cf.taste.recommender.RecommendedItem;

/**
* Servlet implementation class demo
 */
   public class demo extends HttpServlet {
   private static final long serialVersionUID = 1L;

/**
 * @see HttpServlet#HttpServlet()
 */
      public demo() {
      super();
    // TODO Auto-generated constructor stub
    }

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
      response.getWriter().append("Served at:   ").append(request.getContextPath());
   }

/**
 * @throws IOException 
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
    // TODO Auto-generated method stub

        String n = request.getParameter("name");
        int k = Integer.parseInt(n);
        PrintWriter out = response.getWriter();
        List<RecommendedItem> recommendations = new ArrayList<RecommendedItem>  ();

       try {
          recommendations = App.getRecommend(k);
        } catch (Exception e) {
        // TODO Auto-generated catch block
            e.printStackTrace();
        }

          for (RecommendedItem recommendation : recommendations) {
          out.println(recommendation);





  }

 }}

app.java - logic for generating recommendations

      package com.issac;

      import java.io.File;
      import java.util.List;

      import org.apache.mahout.cf.taste.impl.model.file.FileDataModel;
      import org.apache.mahout.cf.taste.impl.neighborhood.ThresholdUserNeighborhood;
      import org.apache.mahout.cf.taste.impl.recommender.GenericUserBasedRecommender;
      import org.apache.mahout.cf.taste.impl.similarity.PearsonCorrelationSimilarity;
      import org.apache.mahout.cf.taste.model.DataModel;
      import org.apache.mahout.cf.taste.neighborhood.UserNeighborhood;
      import org.apache.mahout.cf.taste.recommender.RecommendedItem;
      import org.apache.mahout.cf.taste.recommender.UserBasedRecommender;
      import org.apache.mahout.cf.taste.similarity.UserSimilarity;


      public class App 
 {
    public static List<RecommendedItem> getRecommend(int k) throws Exception
 {
    DataModel model = new FileDataModel(new File("data/dataset.csv"));
    UserSimilarity similarity = new PearsonCorrelationSimilarity(model);
    UserNeighborhood neighborhood = new ThresholdUserNeighborhood(0.1,  similarity, model);
 UserBasedRecommender recommender = new      GenericUserBasedRecommender(model, neighborhood, similarity);
      List<RecommendedItem> recommendations = recommender.recommend(k, 3);
      return recommendations;
     }
  }

stack trace of eclipse console-

         INFO: Server startup in 15288 ms
          SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
          SLF4J: Defaulting to no-operation (NOP) logger implementation
      SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
      java.io.FileNotFoundException: data\dataset.csv
      at org.apache.mahout.cf.taste.impl.model.file.FileDataModel.<init>   (FileDataModel.java:182)
      at org.apache.mahout.cf.taste.impl.model.file.FileDataModel.<init>(FileDataModel.java:169)
      at org.apache.mahout.cf.taste.impl.model.file.FileDataModel.<init>(FileDataModel.java:149)
      at com.issac.App.getRecommend(App.java:24)
      at com.issac.demo.doPost(demo.java:51)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
      at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilt erChain.java:292)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
  at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)

enter image description here


Solution

  • So this is how it worked out for me. After getting FileNotFound exception,I tried this->

     ClassLoader classLoader = App.class.getClassLoader();
     DataModel model = new FileDataModel(new File(classLoader.getResource("data/dataset.csv").getFile()));
    

    instead of

     DataModel model = new FileDataModel(new File("data/dataset.csv"));
    

    I don't have thorough knowledge about why it worked just found it on internet, has something to do with class FileDataModel's parameters. Anyone who can give explanation is welcome.