How to use JNDI DataSource provided by Tomcat in S

Question

It is said in Spring javadoc article about DriverManagerDataSource class, that this class is very simple and that it is recommended

to use a JNDI DataSource provided by the container. Such a DataSource can be exposed as a DataSource bean in a Spring ApplicationContext via JndiObjectFactoryBean

The question is: how to accomplish this?

For example if I wish to have DataSource bean to access my custo mysql database, what I require then? What to write in context configuration etc?

Answer 1

In your spring class, You can inject a bean annotated like as

@Autowired
@Qualifier("dbDataSource")
private DataSource dataSource;

and You add this in your context.xml

<beans:bean id="dbDataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
    <beans:property name="jndiName" value="java:comp/env/jdbc/MyLocalDB"/>
</beans:bean>

You can declare the JNDI resource in tomcat's server.xml using

<Resource name="jdbc/TestDB" 
  global="jdbc/TestDB" 
  auth="Container" 
  type="javax.sql.DataSource" 
  driverClassName="com.mysql.jdbc.Driver" 
  url="jdbc:mysql://localhost:3306/TestDB" 
  username="pankaj" 
  password="pankaj123" 

  maxActive="100" 
  maxIdle="20" 
  minIdle="5" 
  maxWait="10000"/>

back to context.xml de spring add this

<ResourceLink name="jdbc/MyLocalDB"
                global="jdbc/TestDB"
                auth="Container"
                type="javax.sql.DataSource" />

if, like this exmple you are injecting connection to database, make sure that MySQL jar is present in the tomcat lib directory, otherwise tomcat will not be able to create the MySQL database connection pool.

Answer 2

According to Apache Tomcat 7 JNDI Datasource HOW-TO page there must be a resource configuration in web.xml:

<resource-ref>
  <description>DB Connection</description>
  <res-ref-name>jdbc/TestDB</res-ref-name>
  <res-type>javax.sql.DataSource</res-type>
  <res-auth>Container</res-auth>

That works for me

Answer 3

Documentation: C.2.3.1 <jee:jndi-lookup/> (simple)

Example:

<jee:jndi-lookup id="dataSource" jndi-name="jdbc/MyDataSource"/>

You just need to find out what JNDI name your appserver has bound the datasource to. This is entirely server-specific, consult the docs on your server to find out how.

Remember to declare the jee namespace at the top of your beans file, as described in C.2.3 The jee schema.

Answer 4

If using Spring's XML schema based configuration, setup in the Spring context like this:

<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:jee="http://www.springframework.org/schema/jee" xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd">
...
<jee:jndi-lookup id="dbDataSource"
   jndi-name="jdbc/DatabaseName"
   expected-type="javax.sql.DataSource" />

Alternatively, setup using simple bean configuration like this:

<bean id="DatabaseName" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName" value="java:comp/env/jdbc/DatabaseName"/>
</bean>

You can declare the JNDI resource in tomcat's server.xml using something like this:

<GlobalNamingResources>
    <Resource name="jdbc/DatabaseName"
              auth="Container"
              type="javax.sql.DataSource"
              username="dbUser"
              password="dbPassword"
              url="jdbc:postgresql://localhost/dbname"
              driverClassName="org.postgresql.Driver"
              initialSize="20"
              maxWaitMillis="15000"
              maxTotal="75"
              maxIdle="20"
              maxAge="7200000"
              testOnBorrow="true"
              validationQuery="select 1"
              />
</GlobalNamingResources>

And reference the JNDI resource from Tomcat's web context.xml like this:

  <ResourceLink name="jdbc/DatabaseName"
   global="jdbc/DatabaseName"
   type="javax.sql.DataSource"/>

Reference documentation:

• Tomcat 8 JNDI Datasource HOW-TO
• Tomcat 8 Context Resource Links Reference
• Spring 4 JEE JNDI Lookup XML Schema Reference
• Spring 4 JndiObjectFactoryBean Javadoc

Edit: This answer has been updated for Tomcat 8 and Spring 4. There have been a few property name changes for Tomcat's default datasource resource pool setup.

Answer 5

Assuming you have a "sampleDS" datasource definition inside your tomcat configuration, you can add following lines to your applicationContext.xml to access the datasource using JNDI.

<jee:jndi-lookup expected-type="javax.sql.DataSource" id="springBeanIdForSampleDS" jndi-name="sampleDS"/>

You have to define the namespace and schema location for jee prefix using:

xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd"

Answer 6

With Spring's JavaConfig mechanism, you can do it like so:

@Configuration
public class MainConfig {

    ...

    @Bean
    DataSource dataSource() {
        DataSource dataSource = null;
        JndiTemplate jndi = new JndiTemplate();
        try {
            dataSource = jndi.lookup("java:comp/env/jdbc/yourname", DataSource.class);
        } catch (NamingException e) {
            logger.error("NamingException for java:comp/env/jdbc/yourname", e);
        }
        return dataSource;
    }

}