android - Cordova plugin javascript not getting response data from Plugin -

i using cordova develop hybird app android. writing simple plugin alert "hello" message.

so have testplugin.java

public class testplugin extends cordovaplugin {      @override     public boolean execute(final string action, final jsonarray args, final callbackcontext callbackcontext) throws jsonexception {          callbackcontext.sendpluginresult(new pluginresult(pluginresult.status.ok, "hello"));         return true;     } } 

my config.xml:

<?xml version='1.0' encoding='utf-8'?> <widget id="com.essue.magicmirror" version="0.0.1" xmlns="http://www.w3.org/ns/widgets" xmlns:cdv="http://cordova.apache.org/ns/1.0">     <name>myproject</name>     <description>         sample apache cordova application responds deviceready event.     </description>     <author email="dev@cordova.apache.org" href="http://cordova.io">         apache cordova team     </author>     <content src="index.html" />     <access origin="*" />         <feature name="testplugin">         <param name="android-package" value="com.my.project.plugin.testplugin" />     </feature>  </widget> 

relevant part of index.html:

<script>     $('.start-btn').click(function() {         cordova.exec(new function(data){         alert(data);          }, null, "testplugin", "say", []);     });  </script> 

when button $('.start-btn') clicked, alert pops "undefined", means not getting response text plugin.

am missing something? thanks