Friday, December 6, 2013

Access Liferay Database Services in Themes/Velocity Templates

Access Liferay Database Services in Themes/Velocity Templates

Access liferay database services in themes. Means access Locals Service and Service classes in liferay themes.

Generally some time we need to show some dynamic data in theme, the data may be stored in any table in liferay database .When we get such requirement we need to access database from vm files.
In theme level liferay have given service locater feature to access database services.

Here we are talking about theme means we are access liferay services in portal_normal.vm file or other VM (velocity) files which is in liferay themes.

In liferay themes all VM (velocity) files available in templates directory. One of the  core velocity file is portal_normal.vm.

Liferay already providing many default velocity variables in theme level such as
$theme_display, $portlet_display, $layout, $company and $user.

These variables we can see in init.vm file we can use these variables anywhere in theme vm files when we include vm file in our working velocity file.

Liferay already include this in portal_notmal.vm file so that we can use any variable which is available in init.vm

Information about velocity

Velocity is a Java-based template engine. It permits anyone to use a simple yet powerful template language to reference objects defined in Java code.

Liferay uses velocity templates to aggregate dynamic content of  web page.

Here all variable which starts with $ symbol

The following is link to know more about velocity

Declare variable and assign value

#set( $a = "Velocity" )

Print variable  

#set( $foo = "Velocity" )
Hello $foo World!

In liferay we can see many declaration of variables in init.vm file for example as follows

#set ($user_name = $user.getFullName())

To print user Name

Hi I am $user_name


Whenever it find the $ it will interpret as velocity variable by velocity engine while rendering.
This is enough for us to understand about velocity.

Now accessing liferay data base services in themes

  1. Make it available of service jar file in liferay global class path
  2. Use velocity service locater to find data base service in theme

Make it available of service jar file in liferay global class path

Foremost thing is your service jar file should be available in liferay portal global class path
Means liferay portal service (portal-service.jar) available in liferay portal global class path. By default this jar file available in global lib directory of portal.

For Tomcat:

The following is liferay portal global class path


 If any jar file which is available in tomcat-7.0.27\lib\ext path then it can be available to liferay portal and plug-in portlets too.

By default liferay portal service jar file available in global lib so we can access all liferay portal services such as UserLocalService,GrouopLocalService and LayoutLolcaServices.


 There are many services available in liferay portal level all clasess you can find in portal-service.jar the following packages com.liferay.portal.service.

For JBoss:

The following is liferay portal global class path


When we work with Liferay JBoss Server this is something different from tomcat server.
For JBoss the service jar file should available in following location then it will be treated as global jar so that all liferay portlets can access these classes.


Once we place the jar in the location we need to entry the jar file name in module.xml file. The module.xml also in same location i.e. jboss7.1.1\modules\com\liferay\portal\main

Example for entries like follows

<resource-root path="portal-service.jar" />

module.xml file

<module xmlns="urn:jboss:module:1.0" name="com.liferay.portal">
                        <resource-root path="hsql.jar" />
                        <resource-root path="jtds.jar" />
                        <resource-root path="portal-service.jar" />
                        <resource-root path="portlet.jar" />
                        <resource-root path="postgresql.jar" />
                        <resource-root path="mysql.jar" />
                        <resource-root path="ojdbc6.jar" />       
                        <module name="javax.api" />
                        <module name="javax.mail.api" />
                        <module name="javax.servlet.api" />
                        <module name="javax.servlet.jsp.api" />
                        <module name="javax.transaction.api" />


Liferay by default make the portal services in global class path level in JBoss .
So we need not do anything and we can use directly all portal service which in portal-service.jar file.

Use velocity service locater to find data base service in theme

We can access any portal service in them i.e. in portal_noraml.vm file or other vm files in liferay. Because liferay already provided porta-service.jar file in global class path , so we can access in liferay themes.

In Liferay theme all vm files included in portal_noraml.vm file this is core vm file for liferay to aggregate all web page content.

If you use any vm file then it should be included in portal_noram.vm file then only it will be rendered.

To access services in them liferay provided service locater in velocity by using this we can get the services in themes.

We have default velocity variable $serviceloacater we can use this variable to get the service.

The following is example code

#set ($userLocalService= $serviceLocator.findService("com.liferay.portal.service.UserLocalService"))

In above code we get the user Service and make sure we have to use full qualified path of java class means class name including package name.

Example like this

com.liferay.portal.service.UserLocalService this is nothing but class in portal-service.jar file.

Once we get the service object we can apply any method which available in service class.

Example code as follows

#set ($userLocalService= $serviceLocator.findService("com.liferay.portal.service.UserLocalService"))
#set ($user = $userLocalService.getUserById($request.get("theme-display").get("user-id")))
#set ($emailAddress = $user.getEmailAddress())

Now we can simple print email address like this in portal_noram.vm file as follows


This just example snippet I showed and we already have direct $user object in theme we can use directly that to get user information.

Examples for Services in portal

#set ($userLocalService= $serviceLocator.findService("com.liferay.portal.service.UserLocalService"))

#set ($groupLocalService= $serviceLocator.findService("com.liferay.portal.service.GroupLocalService"))

#set ($layoutLocalService= $serviceLocator.findService("com.liferay.portal.service.LayoutLocalService"))

#set ($roleLocalService= $serviceLocator.findService("com.liferay.portal.service.RoleLocalService"))

Like this we can access any portal services in portal_normal.vm file

Accessing plug-in portlet services in themes

We already know to access portal services but some time we may get requirement to access plug-in portlet services that is our custom services.

The following are the steps
  1. Create plug-in portlet using Liferay IDE with eclipse.
  2. Write entities in service.xml file
  3. Run service builder
  4. Once service builder successfully run then you will get service jar file in plug-in portlet WEB-INF/lib directory.
  5. Copy the plug-in portlet service jar file and place this into liferay global lib directory based on your liferay server (JBoss/Tomcat)
  6. Remove service jar file from plug-in portlet WEB-INF/lib directory
  7. Now deploy portlet and  portlet should be successfully deployed
  8. Now use service locater to get the plug-in service in theme or portal_normal.vm


Portlet Name: Student-portlet

Table Name: Student

service.xml file as follows

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE service-builder PUBLIC "-//Liferay//DTD Service Builder 6.1.0//EN"
<service-builder package-path="com.meera.db">
            <entity name="Student" local-service="true" remote-service="true">
                        <column name="studentId" type="long" primary="true" />
                        <column name="studentName" type="String" />
                        <column name="studentAddress" type="String" />

Now run service builder once run service builder successfully then you can get Student-portlet-service.jar in WEB-INF/lib

Now we have to copy Student-portlet-service.jar file to liferay global lib

If Tomcat


If JBoss


Register jar file name in module.xml as follows

<resource-root path=" Student-portlet-service.jar" />

Remove Student-portlet-service.jar file form portlet WEB-INF/lib directory

Now deploy then portlet and portlet should be successfully deployed.

Now use following code in portal_normal.vm of your currently working theme

#set ($studentLocalService= $serviceLocator.findService("com.liferay.portal.service.UserLocalService"))
#set ($student = $studentLocalService.getStudent(1)
#set ($studentName= $student.getStudentName())
<div>Hi I am student  my name is <h1>($studentName</h1></div>


When we use plugin portlet services in then we have to apply above steps to each change/modification  in plug-in portlet services .so make sure you have to follow the steps properly for each change.

Important points

  • Liferay provide many velocity variables to use in themes.
  • Service locater is one velocity variable in liferay from that we can get any services from liferay.
  • To access service in liferay all services should be in Liferay Global class path.

Reference Links:

Meera Prince


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