How to use JNDI DataSource provided by Tomcat in Spring?

问题

It is said that in the 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 do I accomplish this?

For example, if I wish to have DataSource bean to access my custom MySQL database, what would I require then? What should I write in the context configuration, etc?

回答1:

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.

回答2:

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;
    }

}

回答3:

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"

回答4:

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.

回答5:

Another feature: instead of of server.xml, you can add "Resource" tag in
your_application/META-INF/Context.xml (according to tomcat docs) like this:

<Context>
<Resource name="jdbc/DatabaseName" auth="Container" type="javax.sql.DataSource"
  username="dbUsername" password="dbPasswd"
  url="jdbc:postgresql://localhost/dbname"
  driverClassName="org.postgresql.Driver"
  initialSize="5" maxWait="5000"
  maxActive="120" maxIdle="5"
  validationQuery="select 1"
  poolPreparedStatements="true"/>
</Context>

回答6:

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

回答7:

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.

回答8:

I found this solution very helpful in a clean way to remove xml configuration entirely.

Please check this db configuration using JNDI and spring framework. http://www.unotions.com/design/how-to-create-oracleothersql-db-configuration-using-spring-and-maven/

By this article, it explain how easy to create a db confguration based on database jndi(db/test) configuration. once you are done with configuration then all the db repositories are loaded using this jndi. I did find useful. If @Pierre has issue with this then let me know. It's complete solution to write db configuration.

来源：https://stackoverflow.com/questions/9183321/how-to-use-jndi-datasource-provided-by-tomcat-in-spring

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