Liferay 7 overriding MVC Commands

• MVCActionCommand: An interface that allows the portlet to process a particular action request. By extending BaseMVCActionCommand, we can customize processAction method.
• MVCRenderCommand: An interface that handles the render phase of the portlet. By  extending BaseMVCRenderCommand, we can customize render method.
• MVCResourceCommand: An interface that allows the portlet to serve a resource. By extending BaseMVCResourceCommand, we can customize serveResource method.

Now , we will see how to customize processAction method.

Step 1:

Initially, Create one module as mentioned in Liferay 7 document.

Step 2:

In controller class, write the component property depends on which modules you are customizing,

for eg., if we customize create account page, write as following

@Component(

property = {

"javax.portlet.name=com_liferay_login_web_portlet_FastLoginPortlet",

"javax.portlet.name=com_liferay_login_web_portlet_LoginPortlet" ,

"mvc.command.name=/login/create_account",

"service.ranking:Integer=100" 

},

service = MVCActionCommand.class

)

Note : service = MVCActionCommand.class is based on which interface we are overriding.

Step 3:

For MVC action command overrides, extend BaseMVCActionCommand, and the only method you’ll need to override is doProcessAction, which must return void.

for eg.,

public class samplePortlet extends BaseMVCActionCommand  {

@Override

protected void doProcessAction(

ActionRequest actionRequest, ActionResponse actionResponse)

throws Exception {

  mvcActionCommand.processAction(actionRequest, actionResponse); // it process existing logic

System.out.println("inside process action");

}

@Reference(
       target = "(&(mvc.command.name=/login/create_account)(javax.portlet.name=com_liferay_login_web_portlet_LoginPortlet))"
       )
public void setMvcActionCommand(MVCActionCommand mvcActionCommand) {
     this.mvcActionCommand = mvcActionCommand;
   }
protected MVCActionCommand mvcActionCommand;

}

For more details, Refer here.