Portlet Filters In Liferay 7 DXP

Portlet Filter is used to intercept and manipulate the request and response before it is delivered to the portlet at given life cycle such as action, render and resource

Environment
Liferay IDE 3.1.2 GA3
Liferay CE Portal Tomcat 7 GA4
JDK 8
MySql 5.7

What is Portlet Filter?

Portlet Filter is used to intercept and manipulate the request and response before it is delivered to the portlet at given life cycle such as action, render and resource

Types Of Filters For A Liferay Portlet

Action Filter
Render Filter
Resource Filter
Base Filter

Which Filter To Use?

Action Filter : To Intercept only The Action Requests
Render Filter : To Intercept only The Render Requests
Resource Filter : To Intercept only The Resource Requests
Base Filter : To Intercept all the http request comes to your portlet.

How to Implement Portlet Filter In liferay 7 DXP?

Step 1 : Create A Module Project for Portlet
If you want to know how to create a portlet module project in Liferay 7 DXP, please refer my earlier blog, Below is my Portlet Controller Class.

Step 2 : Create A Portlet Filter Component Class
You can create Portlet Filter Component Class Using Eclipse, by right clicking on you portlet module project and select select "New Component Class" and Select "Portlet Filter" Component Template, I prefer to create a class manually for now, I Am creating a Class named "MyRenderFilter"

Step 3 : Component Declaration
Declare the Class as an OSGI Component Using the Below Code Snippet

import org.osgi.service.component.annotations.Component;
import javax.portlet.filter.PortletFilter;
@Component(immediate = true, 
 property = {
  "javax.portlet.name="+MyPortletKeys.My, 
 },
 service = PortletFilter.class
)

Note : Make sure you give correct portlet name and service must be PortletFilter.class

Step 4 : Extend The RenderFilter

import javax.portlet.filter.RenderFilter;
public class MyRenderFilter implements RenderFilter{}

Step 5 : Implement Unimplemented Methods of the Parent Class RenderFilter

public void init();
public void destroy();
public void doFilter();

Complete MyRenderFilter.java Code

Each time when you Hit a Render URL doFilter() method the MyRenderFilter will be triggered.

Portlet Filter For Action Request

Similarly You can create the filter for all Action Request By extending ActionFilter Class, as shown below

Portlet Filter For Resource Request

For all Resource request you can extend your class with ResourceFilter Class, as shown below

Servlet Filter In Liferay 7 DXP

This Filter Intercepts all the requests comes to the portlet, whether it is action, render, resource and it also can be HttpServletRequest , if you want filter all the Http Servlet Request comes to your portlet please use this filter, your filter component just have to extend "BaseFilter" Class, refer the below code

Note : This BaseFilter Will be Triggered Before all the other filters such as ActionFilter, RenderFilter and ResourceFilter.
I have created a portlet which can easily make you understand flow of Portlet Filters and Portlet Requests In detail, please download the portlet and deploy to test, it can give more insight into the portlet Filters In Liferay, when you add this portlet to the page init() and doFilter() method will be triggered.


Source Code