Connecting Service Builder to External Databases

Sometimes you want to use a database other than Liferay DXP’s. To do this, its data source must be defined in portal-ext.properties or configured as a JNDI data source on the app server. This tutorial shows how to connect Service Builder to a data source. Here’s how:

  1. Specify the data source.

  2. Create a Spring bean that points to the data source.

  3. Set your entity’s data source to the liferayDataSource alias.

  4. Run Service Builder.

First, use portal properties to set your data source.

Step 1: Specify the Data Source

If the application server defines the data source using JNDI, skip this step. Otherwise, specify the data source in a portal-ext.properties file. Distinguish it from Liferay’s default data source by giving it a prefix other than jdbc.default.. This example uses prefix jdbc.ext.:

jdbc.ext.driverClassName=org.mariadb.jdbc.Driver
jdbc.ext.password=userpassword
jdbc.ext.url=jdbc:mariadb://localhost/external?useUnicode=true&characterEncoding=UTF-8&useFastDateParsing=false
jdbc.ext.username=yourusername

Step 2: Create a Spring Bean that Points to the Data Source

To do this, create a parent context extension (e.g.,ext-spring.xml) in your Service Builder module’s src/main/resources/META-INF/spring/parent folder or in your traditional portlet’s WEB-INF/src/META-INF/parent folder. Create this folder if it doesn’t exist already.

Define the following elements:

  1. A data source factory Spring bean for the data source. It’s different based on the type.

    • JNDI: Specify an arbitrary property prefix and prepend the prefix to a JNDI name property key. Here’s an example:

        <bean class="com.liferay.portal.dao.jdbc.spring.DataSourceFactoryBean"
            id="liferayDataSourceFactory">
            <property name="propertyPrefix" value="custom." />
            <property name="properties">
                <props>
                    <prop key="custom.jndi.name">jdbc/externalDataSource</prop>
                </props>
            </property>
        </bean>
      
    • Portal Properties: Specify a property prefix that matches the prefix (e.g., jdbc.ext.) you used in portal-ext.properties.

        <bean class="com.liferay.portal.dao.jdbc.spring.DataSourceFactoryBean"
            id="liferayDataSourceFactory">
            <property name="propertyPrefix" value="jdbc.ext." />
        </bean>
      
  2. A Liferay data source bean that refers to the data source factory Spring bean.

  3. An alias for the Liferay data source bean.

Here’s an example ext-spring.xml that points to a JNDI data source:

<?xml version="1.0"?>

<beans default-destroy-method="destroy" default-init-method="afterPropertiesSet"
   xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

   <!-- To define an external data source, the liferayDataSource Spring bean 
       must be overridden. Other default Spring beans like liferaySessionFactory 
       and liferayTransactionManager may optionally be overridden. 

       liferayDataSourceFactory refers to the data source configured on the
       application server. -->
   <bean class="com.liferay.portal.dao.jdbc.spring.DataSourceFactoryBean"
       id="liferayDataSourceFactory">
       <property name="propertyPrefix" value="custom." />
       <property name="properties">
           <props>
               <prop key="custom.jndi.name">jdbc/externalDataSource</prop>
           </props>
       </property>
   </bean>

   <!-- The data source bean refers to the factory to access the data source.
   -->
   <bean
       class="org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy"
       id="liferayDataSource">
       <property name="targetDataSource" ref="liferayDataSourceFactory" />
   </bean>

   <!-- In service.xml, we associated our entity with the extDataSource. To 
       associate the extDataSource with our overridden liferayDataSource, we define 
       this alias. -->
   <alias alias="extDataSource" name="liferayDataSource" />
</beans>

The liferayDataSourceFactory above refers to a JNDI data source named jdbc/externalDataSource. If the data source is in a portal-ext.properties file, the bean requires only a propertyPrefix property that matches the data source property prefix.

The data source bean liferayDataSource is overridden with one that refers to the liferayDataSourceFactory bean. The override affects this bundle (module or Web Application Bundle) only.

The alias extDataSource refers to the liferayDataSource data source bean.

Step 3: Set Your Entity’s Data Source to the liferayDataSource Alias

In your service.xml file, set your entity’s data source to the liferayDataSource alias you specified in your ext-spring.xml file. Here’s an example:

<?xml version="1.0"?>
<!DOCTYPE service-builder PUBLIC "-//Liferay//DTD Service Builder 7.1.0//EN"
    "http://www.liferay.com/dtd/liferay-service-builder_7_1_0.dtd">

<service-builder package-path="com.liferay.example" >
    <namespace>TestDB</namespace>
    <entity local-service="true" name="Foo" table="testdata" data-source="extDataSource"
            remote-service="false" uuid="false">
           <column name="id" db-name="id" primary="true" type="long" />
           <column name="foo" db-name="foo" type="String" />
           <column name="bar" db-name="bar" type="long" />
    </entity>
</service-builder>

Note the example’s <entity> tag attributes:

data-source: The liferayDataSource alias ext-spring.xml specifies.

table: Your entity’s database table.

Also note that your entity’s <column>s must have a db-name attribute set to the column name.

Step 4: Run Service Builder

Run Service Builder. Now your Service Builder services use the data source. You can use the services in your business logic as you always have regardless of the underlying data source.

Congratulations! You’ve connected Service Builder to your external data source.

Connecting to JNDI Data Sources

Service Builder

Running Service Builder and Understanding the Generated Code

Business Logic with Service Builder

« Configuring service.propertiesCustom SQL »
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