• http://localhost:8081 :- is the protocol and host address + port
• /web/guest/test :- There are 3 parts. 1) /Web 2) /guest and 3) /test. /test is a friendly url of Liferay public page test. Since its public page, /web is added. While /guest is a friendly url of guest community.
• p_auth=R9q2yoCH:- is the authentication token generated by liferay for security purpose and it will be changed on each submit.
• p_p_id :- is portlet Id (friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6 in our case) which will be derived from the name of the portlet (defined in portlet.xml file)
• p_p_lifecycle=1 :- which shows the life cycle phase of current request. Since we are calling action method,'1' denotes that the current request is in action phase. Apart from action phase, portlet have render, resource and even phase. 
• p_p_state :- denotes Liferay page's window state. There are 3 possible values 1)Normal 2)Maximize and 3) Minimize. We are currently normal state. You can change the state by clicking Maximize / Minimize button at right side top bar of portlet.
• p_p_mode :- shows the mode of portlet. there are various mode of portlet like view, edit, help etc. Currently we are in view mode.
• p_p_col_id :- This is reference ID of the column in liferay template. there are various out of the box layout template available (like one column, two column(30-70) etc). So this parameter will show the id of the column where our portlet resides. 
• p_p_col_pos :- This parameter is not present in the URL because we have used one column layout. If layout having more than one columns then this parameter will be added to URL. Its showing the position of column in which our portlet is placed.
• p_p_col_count:- This parameter shows the no of columns in current layout. Currently we have only one.
• [p_p_id]_action :- Any parameter in this URL which is prefixed with portlet Id ( friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6 in our case) is the parameter set by that portlet. In our case we have used action parameter to pick corresponding action method.(we have passed action parameter by <portlet:param name="action" value="userName"></portlet:param> )

<?xml version="1.0"?>
<!DOCTYPE liferay-portlet-app PUBLIC "-//Liferay//DTD Portlet Application 6.0.0//EN" "http://www.liferay.com/dtd/liferay-portlet-app_6_0_0.dtd">

<liferay-portlet-app>
 <portlet>
  <portlet-name>friendly-url</portlet-name>
  <icon>/icon.png</icon>
  <friendly-url-mapper-class>com.liferay.portal.kernel.portlet.DefaultFriendlyURLMapper</friendly-url-mapper-class>
  <friendly-url-mapping>submit-name</friendly-url-mapping>
  <friendly-url-routes>com/opensource/techblog/controller/friendly-url-router.xml</friendly-url-routes>
  <instanceable>true</instanceable>
  <header-portlet-css>/css/main.css</header-portlet-css>
  <footer-portlet-javascript>/js/main.js</footer-portlet-javascript>
  <css-class-wrapper>friendly-url-portlet</css-class-wrapper>
 </portlet>
 <role-mapper>
  <role-name>administrator</role-name>
  <role-link>Administrator</role-link>
 </role-mapper>
 <role-mapper>
  <role-name>guest</role-name>
  <role-link>Guest</role-link>
 </role-mapper>
 <role-mapper>
  <role-name>power-user</role-name>
  <role-link>Power User</role-link>
 </role-mapper>
 <role-mapper>
  <role-name>user</role-name>
  <role-link>User</role-link>
 </role-mapper>
</liferay-portlet-app>

• We have added 3 elements. 1)friendly-url-mapping-class 2)friendly-url-mapping and 3)friendly-url-routes
• friendly-url-mapping-class is the the class which will help us to get friendly url. This class is provided by Liferay.
• The value of friendly-url-mapping will be used in url. Its kind of key that will map the friendly url with the actual portlet url at server side.
• friendly-url-routes will be path of the xml file that we have defined. This xml file is called router.
• entry of these elements should be same order as I have defined and they must be placed just immediate after <icon> element.

• In this example we have used instanceable portlet. Because of this its generating the p_p_id as friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6
• In this p_p_id the last 4 characters are instance key and it will only be generate when we place portlet on page. So that they are dynamic
• It means If I place the portlet on page then let say the instance Id generated is pkd5 and when I remove the portlet from page and again if I place it then this time its not necessary that the same instance Id is generated.
• This create the problem as you can see that we have given p_p_id in router xml as implicit parameter.
• So the best practice is that make portlet non-instanceable (by setting instanceable element false in liferay-portlet.xml file) while generating its friendly URL.
• You also have observed that I have defined the action implicit variable, which is nothing but the corresponding action method key so this url will

package com.opensource.techblog.controller;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.portlet.bind.annotation.ActionMapping;
import org.springframework.web.portlet.bind.annotation.RenderMapping;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.util.ParamUtil;

@Controller(value = "FriendlyUrlController")
@RequestMapping("VIEW")
public class FriendlyUrlController {

 private static Log log = LogFactoryUtil.getLog(FriendlyUrlController.class);
 /*
  * Default Render Method
  */
 @RenderMapping
 public String handleRenderRequest(RenderRequest request,RenderResponse response,Model model){
  
  return "view";
 }
 
 @ActionMapping(params = "action=addUserName") 
 public void addUserName(ActionRequest request, ActionResponse response) {
  String userName=ParamUtil.get(request, "userName", "");
  log.info("userName is==>"+userName);
 }
 
 @RenderMapping(params ="action=viewUser")
 public String viewUser(RenderRequest request,RenderResponse response,Model model){
  
  return "viewUser";
 }
 @RenderMapping(params ="action=editUser")
 public String editUser(RenderRequest request,RenderResponse response,Model model){
  
  return "editUser";
 }
 

}

• I have added 2 render method which will just display different JSP files. These render method will be called based on matching keys( viewUser and editUser)
• We also have to create corresponding JSP (viewUser.jsp and editUser.jsp at the same path where we have defined view.jsp (iser /WEB-INF/jsp folder)

<?xml version="1.0"?>
<!DOCTYPE routes PUBLIC "-//Liferay//DTD Friendly URL Routes 6.0.0//EN" "http://www.liferay.com/dtd/liferay-friendly-url-routes_6_0_0.dtd">

<routes>
 <route>
  <pattern>/add</pattern>
  <implicit-parameter name="p_p_id">friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6</implicit-parameter>
  <implicit-parameter name="p_p_lifecycle">1</implicit-parameter>
  <implicit-parameter name="p_p_state">normal</implicit-parameter>
  <implicit-parameter name="p_p_mode">view</implicit-parameter>
  <implicit-parameter name="action">addUserName</implicit-parameter>
 </route>
 <route>
  <pattern>/view</pattern>
  <implicit-parameter name="p_p_id">friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6</implicit-parameter>
  <implicit-parameter name="p_p_lifecycle">0</implicit-parameter>
  <implicit-parameter name="p_p_state">normal</implicit-parameter>
  <implicit-parameter name="p_p_mode">view</implicit-parameter>
  <implicit-parameter name="action">viewUser</implicit-parameter>
 </route>
 <route>
  <pattern>/edit</pattern>
  <implicit-parameter name="p_p_id">friendlyurl_WAR_friendlyurlportlet_INSTANCE_dkW6</implicit-parameter>
  <implicit-parameter name="p_p_lifecycle">0</implicit-parameter>
  <implicit-parameter name="p_p_state">normal</implicit-parameter>
  <implicit-parameter name="p_p_mode">view</implicit-parameter>
  <implicit-parameter name="action">editUser</implicit-parameter>
 </route>
</routes>

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

<portlet:defineObjects />

<portlet:actionURL var="userNameUrl">
<portlet:param name="action" value="addUserName"></portlet:param>
</portlet:actionURL>

<portlet:renderURL var="viewUserUrl">
<portlet:param name="action" value="viewUser"></portlet:param>
</portlet:renderURL>

<portlet:renderURL var="editUserUrl">
<portlet:param name="action" value="editUser"></portlet:param>
</portlet:renderURL>

<form action="${userNameUrl}" method="post">
 Name :- <input type="text" name="userName"><br>
 <a href="${viewUserUrl}">view User</a>
 <a href="${editUserUrl}">edit User</a>
 <input type="submit">
</form>