title: No such file or directory error even the file exists in Java
body: <p>I am a newbie to Java and I wish to run the library <code>JGibbLDA</code>. I did as required by the document, enter the root directory of <code>JGibbLDA-v.1.0</code> and input the command:</p>
  
  <pre><code>java -mx512M -cp bin:lib/args4j-2.0.6.jar jgibblda.LDA -est -alpha 0.5 -beta 0.1 -ntopics 100 -niters 1000 -savestep 100 -twords 20 -dfile models/data/data.txt
  </code></pre>
  
  <p>But an error occurs:</p>
  
  <pre><code>Read Dataset Error: /models/data/data.txt (No such file or directory)
  java.io.FileNotFoundException: /models/data/data.txt (No such file or directory)
  at java.io.FileInputStream.open0(Native Method)
  at java.io.FileInputStream.open(FileInputStream.java:195)
  at java.io.FileInputStream.&lt;init&gt;(FileInputStream.java:138)
  at java.io.FileInputStream.&lt;init&gt;(FileInputStream.java:93)
  at jgibblda.LDADataset.readDataSet(LDADataset.java:154)
  at jgibblda.Model.initNewModel(Model.java:476)
  at jgibblda.Estimator.init(Estimator.java:45)
  at jgibblda.LDA.main(LDA.java:49)
  Fail to read training data!
  </code></pre>
  
  <p>I don't know why there is a <code>/</code> before the directory in the error log message. But the <code>models/data/data.txt</code> really exist and I can enter <code>models/data</code> at the root directory properly. The related code of the library is as below:</p>
  
  <pre><code>public static LDADataset readDataSet(BufferedReader reader, Dictionary dict){
      try {
          //read number of document
          String line;
          line = reader.readLine();
          int M = Integer.parseInt(line);
          System.out.println("NewM:" + M);
  
          LDADataset data = new LDADataset(M, dict);
          for (int i = 0; i &lt; M; ++i){
              line = reader.readLine();
  
              data.setDoc(line, i);
          }
  
          return data;
      }
      catch (Exception e){
          System.out.println("Read Dataset Error: " + e.getMessage());
          e.printStackTrace();
          return null;
      }
  }
  </code></pre>
  
  <p>I have also tried <code>../../models/data/data.txt</code> but also failed. Do you know how to solve this problem? Thank you in advance!</p>