title: How to call native cordova plugin from javascript function in android?
body: <p>I have created one java class which extends CordovaPlugin.</p>
  
  <p>For eg,</p>
  
  <pre><code>public class SampleCardovaPlugin extends CordovaPlugin {
      @Override
      public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
          if (action.equals("echo")) {
              String message = args.getString(0); 
              this.echo(message, callbackContext);
              return true;
          }
          return false;
      }
  private void echo(String message, CallbackContext callbackContext) {
      if (message != null &amp;&amp; message.length() &gt; 0) { 
          callbackContext.success(message);
      } else {
          callbackContext.error("Expected one non-empty string argument.");
      }
  }
  </code></pre>
  
  <p>}</p>
  
  <p>I'm using cordova2.5.0.</p>
  
  <p>How would I call this plugin from my javascript function? 
  Please do the needful.</p>