Event based IPC (Inter portlet communication using Event)

Create one liferay plugin project with any name as per your requirement naming convention, in my case i have given
InterportletCommunication after this create two portlet, in my case i have given name as follows sender and receiver.


1> Define Event definition in portlet.xml before </portlet-app> tag ends.

 <event-definition xmlns:x='http://liferay.com'>
  <qname>x:sharingValues</qname>
  <value-type>java.lang.String</value-type>
 </event-definition>

*qname represents qualified name and in value-type tag we are giving what type of object it is, in this case it is String object.

2> Define supported publishing event in portlet.xml for sender portlet before </portlet>

<supported-publishing-event xmlns:x='http://liferay.com'>
            <qname>x:sharingValues</qname>
</supported-publishing-event>

3> Define supported processing event in portlet.xml for receiver portlet before </portlet>
 
<supported-processing-event xmlns:x='http://liferay.com'>
              <qname>x:sharingValues</qname>
</supported-processing-event>

4> Paste below code in sender portlet view.jsp

<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %>
<%@ taglib uri="http://liferay.com/tld/aui" prefix="aui" %>
<portlet:defineObjects />

<p style="color: green; border: 1px solid green;">This is Sender portlet, this will send/share parameter value with Receiver Portlet.</p>


<portlet:actionURL var="publishEventUrl" name="publishEvent"/>

<aui:form method="post" action="<%=publishEventUrl.toString() %>">
    <aui:input name="publishText" value="" label="Publish Text"/>
    <aui:button type="submit" value="Send"/>
</aui:form>

5>  paste below code in sender portlet java class  Sender.java

package com.test;

import java.io.IOException;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.PortletException;
import javax.xml.namespace.QName;

import com.liferay.portal.kernel.util.ParamUtil;
import com.liferay.util.bridges.mvc.MVCPortlet;

/**
 * Portlet implementation class Sender
 */
public class Sender extends MVCPortlet {

   
    public void publishEvent(ActionRequest actionRequest,
            ActionResponse actionResponse) throws IOException, PortletException {
   
         String publishText = ParamUtil.getString(actionRequest, "publishText");
        
         System.out.println("value got from sender jsp:::"+publishText);
         //NOTE: creating qname object please keep in my mind to import  "import javax.xml.namespace.QName;"
            QName qName = new QName("http://liferay.com", "sharingValues");
            actionResponse.setEvent(qName, publishText);
    }

}




6> paste below code in receiver portlet java class Receiver.java
package com.test;

import javax.portlet.Event;
import javax.portlet.EventRequest;
import javax.portlet.EventResponse;
import javax.portlet.ProcessEvent;

import com.liferay.util.bridges.mvc.MVCPortlet;

/**
 * Portlet implementation class Receiver
 */
public class Receiver extends MVCPortlet {


       @ProcessEvent(qname = "{http://liferay.com}sharingValues")
        public void myEvent(EventRequest request, EventResponse response) {
          
           //NOTE: Creating Event object please keep in mind importing  "javax.portlet.Event;"
            Event event = request.getEvent();
            //Get data from the event
            String valueReceived = (String) event.getValue();
           
            System.out.println("value got in receiver portlet:::"+valueReceived);
        
            response.setRenderParameter("sharingValues", valueReceived);
        }
   
}


7>Paste below code in receiver portlet view.jsp

<%@ taglib uri="http://java.sun.com/portlet_2_0" prefix="portlet" %>
<%@page import="com.liferay.portal.kernel.util.ParamUtil"%>
<portlet:defineObjects />

<p style="color: green; border: 1px solid green;">This is Receiver Portlet, this will receive parameter value send/share by sender portlet.</p>


<%
    String finalValueReceived = (String) renderRequest.getParameter("sharingValues");
%>

<p style="color:green;">Value received from sender portlet:</p><%=finalValueReceived%>