title: speech recognition in java
body: <p>I want to use speech recognition in my project and I found this code but when I run it I get an error which is:</p>
  
  <blockquote>
  <pre><code>run: java.lang.NullPointerException
          at newpackage.HelloWorld.main(HelloWorld.java:55)
  </code></pre>
  </blockquote>
  
  <p>Please could one of you help me in this problem?</p>
  
  <p>This is the server code that I use:</p>
  
  <pre><code>package newpackage;
  
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import javax.speech.*;
  import javax.speech.recognition.*;
  import java.io.FileReader;
  import java.util.Locale;
  
  public class HelloWorld extends ResultAdapter {
    static Recognizer rec;
  
    // Receives RESULT_ACCEPTED event: print it, clean up, exit
    public void resultAccepted(ResultEvent e) {
      Result r = (Result)(e.getSource());
      ResultToken tokens[] = r.getBestTokens();
  
      for (int i = 0; i &lt; tokens.length; i++)
        System.out.print(tokens[i].getSpokenText() + " ");
  
      System.out.println();
      try {
            // Deallocate the recognizer and exit
            rec.deallocate();
      } catch (EngineException ex) {
            Logger.getLogger(HelloWorld.class.getName()).log(Level.SEVERE, null, ex);
      } catch (EngineStateError ex) {
            Logger.getLogger(HelloWorld.class.getName()).log(Level.SEVERE, null, ex);
      }
      System.exit(0);
    }
  
    public static void main(String args[]) {
      try {
        // Create a recognizer that supports English.
        rec = Central.createRecognizer(
                new EngineModeDesc(Locale.ENGLISH));
  
        // Start up the recognizer
        rec.allocate();
  
        // Load the grammar from a file, and enable it
        FileReader reader = new FileReader(args[0]);
        RuleGrammar gram = rec.loadJSGF(reader);
  
        gram.setEnabled(true);
  
        // Add the listener to get results
        rec.addResultListener(new HelloWorld());
  
        // Commit the grammar
        rec.commitChanges();
  
        // Request focus and start listening
        rec.requestFocus();
        rec.resume();
      } catch (Exception e) {
        e.printStackTrace();
            // System.out.println("the problem");
      }
    }
  }
  </code></pre>