Portlet Filter in Liferay 7.2

Liferay 7.2 - Portlet Filter Sample

Overview

This article describes how to create custom portlet filter in Liferay 7.2.

Note: Portet Filters are similar to Servlet Filters, but they are invoked in scope of portlet and, thus, use javax.portlet.PortletRequest / javax.portlet.PortletResponse (instead of javax.servlet.ServletRequest / javax.servlet.ServletResponse).

Why do you need it?

Portlet filter may be used in the following scenarios:

• for custom portlet: to simplify portet's and MVCCommand's code;
• for customization Liferay's OOTB portlets: customization portlets code may be tricky, and you may use portlet filters to inject custom functionality.

Portlet Filter creation

1. Create service Liferay module for the filter class.
2. Define dependencies in build.gradle file:

   dependencies {
       compileOnly group: "com.liferay.portal", name: "com.liferay.portal.kernel", version: "4.0.0"
       compileOnly group: "com.liferay.portal", name: "com.liferay.util.taglib", version: "2.0.0"
       compileOnly group: "javax.portlet", name: "portlet-api", version: "3.0.0"
       compileOnly group: "javax.servlet", name: "javax.servlet-api", version: "3.0.1"
       compileOnly group: "jstl", name: "jstl", version: "1.2"
       compileOnly group: "org.osgi", name: "org.osgi.service.component.annotations", version: "1.4.0"
   }
   

3. Define OSGi metadata in bnd.bnd, sample:

   Bundle-Name: LifeDev AssetPublisher Configuration Portlet Filter
   Bundle-SymbolicName: com.lifedev.asset.publisher.filter
   Bundle-Version: 1.0.0
   

4. Implement filter class, sample:

   @Component(
           immediate = true,
           property = {
                   "javax.portlet.name=com_liferay_portlet_configuration_web_portlet_PortletConfigurationPortlet",
                   "service.ranking:Integer=101"
           },
           service = PortletFilter.class
   )
   public class AssetPublisherConfigurationActionFilter implements ActionFilter {
   
       @Override
       public void init(FilterConfig filterConfig) throws PortletException {
           _log.info("AssetPublisherConfigurationActionFilter => init.");
       }
   
       @Override
       public void doFilter(ActionRequest actionRequest, ActionResponse actionResponse, FilterChain filterChain) throws IOException, PortletException {
           try {
               _log.info("AssetPublisherConfigurationActionFilter => doFilter.");
               //todo: filter logic here
           } catch (Exception e) {
               _log.error(e.getMessage(), e);
           } finally {
               // Invoke the rest of the filters in the chain
               filterChain.doFilter(actionRequest, actionResponse);
           }
       }
   
       @Override
       public void destroy() {
           _log.info("AssetPublisherConfigurationActionFilter => destroy.");
       }
   
       private static final Log _log = LogFactoryUtil.getLog(AssetPublisherConfigurationActionFilter.class);
   }
   

• javax.portlet.name= - portlet name, for which filter is being created (com_liferay_portlet_configuration_web_portlet_PortletConfigurationPortlet in this example),
• service.ranking ranking (priority) of filter's OSGi component.