Writing Google Wave Robots using Java on Intellij

I got my google wave invite two days back (friday night, can't be a better time). And within 4 hours I was talking with my "HelloWorldish" Robot, such is the power and ease to write and deploy a robot is.

If you use eclipse, you already are set and this is the best place to start with : http://code.google.com/apis/wave/extensions/robots/java-tutorial.html

In fact, I used the same page for the sourcecode, and the steps. Make sure, you have a google wave id before you start looking at the next steps.

Steps :-

1.Make sure you are using Java 1.6.

2. I am using Intellij Maia (9). If you are on older version install the google appengine plugin.

3. Use this plugin to generate a dummy web project. In the wizard, choose google app engine. We are not going to use either GWT/ JDO or JPA for this project, so just uncheck them.

4. You can see a "AppEngine Dev" settings to run. Run it ,and you should be able to browse the dummy page at localhost:8080

5. To write the Robot, we need few libraries. Download it from http://code.google.com/p/wave-robot-java-client/downloads/list.

6.create a lib directory inside WEB-INF and copy all these jars . Also, add servlet-api-2.4.jar or higher.

7.Make a package src/parroty.server and copy paste the ParrotyServlet code described at http://code.google.com/apis/wave/extensions/robots/java-tutorial.html

8.Make a web/_wave dir. Create a capabilties.xml file and copy paste the code

<?xml version="1.0" encoding="utf-8"?>
<w:robot xmlns:w="http://wave.google.com/extensions/robots/1.0">
<w:capabilities>
 <w:capability name="WAVELET_PARTICIPANTS_CHANGED" content="true" />
</w:capabilities>
<w:version>1</w:version>
</w:robot>

9. Register your application on appengine site.

In you appengine-web.xml file substitute your application id (instead of mine, "mytestwaveapp") :-

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application>mytestwaveapp</application>
<version>1</version>
</appengine-web-app>

10. Configure your ParrotyServlet inside the web.xml :

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
      version="2.5">
 <servlet>
     <servlet-name>Parroty</servlet-name>
     <servlet-class>parroty.server.ParrotyServlet</servlet-class>
 </servlet>
 <servlet-mapping>
     <servlet-name>Parroty</servlet-name>
     <url-pattern>/_wave/robot/jsonrpc</url-pattern>
 </servlet-mapping>
</web-app>

Go to "Tools->Upload AppEngine Application", and you are good enough to deploy this Robot.It would ask you your appengine loginid/pwd.The console would show, that everything went fine. You can confirm by accessing the capabilties.xmlfile :- http://applicationName.appspot.com/_wave/capabilities.xml

11.Well, now you are done. Use this robot as a participant for your wave and it should answer as I have shown in the picture. More Sample Robot Codes :- http://code.google.com/p/google-wave-resources/source/browse/trunk/samples/extensions/robots/java

Happy Coding ! Happy Waving !!!