<jee:jndi-lookup/> of Tomcat Environment Entries

[crbaker]

This should be in theory really easy but it hasn't been for me so I post of the forum as a last resort.

Problem
Want to be able to set an environment entry in Tomcat context.xml file such as

<Context ...>
  ...
  <Environment name="baseRmiUrl" value="rmi://whatever"
         type="java.lang.String" override="false"/>
  ...
</Context>

and then lookup and retrieve this environment entry inside my spring configuration.

I've look at the documentation here which is about as clear as mud to me.

Spring Documentation

Before...

<bean id="simple" class="org.springframework.jndi.JndiObjectFactoryBean">
    <property name="jndiName" value="jdbc/MyDataSource"/>
    <property name="jndiEnvironment">
        <props>
            <prop key="foo">bar</prop>
        </props>
    </property>
</bean>

After...

<jee:jndi-lookup id="simple" jndi-name="jdbc/MyDataSource">
    <jee:environment>foo=bar</jee:environment>
</jee:jndi-lookup>

How do I get the environment entry and turn that into a string property so that I may reference it in a <bean> such as

    <bean id="remoteAuthenticationService" parent="baseAuthRemoteServerService">
        <property name="serviceUrl">
            <value>${baseRmiUrl}/authenticationService</value>
        </property>
        <property name="serviceInterface">
            <value>com.tangler.service.AuthenticationService</value>
        </property>
    </bean>

[Dave Syer]

In the past I have done this with a custom FactoryBean that turns Jndi entries into properties, and then uses the properties in a PropertyPlaceholderConfigurer. That approach is more general than you need for the one example you showed, but maybe you can use it? What you need is String concatenation in a bean property value - not something you get out of the box, as far as I know, except with a placeholder configurer.

[Rick Evans]

Hi Dave

In the past I have done this with a custom FactoryBean that turns Jndi entries into properties, and then uses the properties in a PropertyPlaceholderConfigurer. That approach is more general than you need for the one example you showed, but maybe you can use it?

Where is this code so that I can use it? If you post it I will see if it is amenable to adding to the Spring reference documentation as an advanced example in the <jee:jndi-lookup/> section.

Cheers
Rick

[Rick Evans]

Hi crbaker

I've look[ed] at the documentation here which is about as clear as mud to me.

Darn, muddy was not what I was aiming for. As you can see I've pinged Dave above to see if we can get the code in place to get you moving, and I will certainly amend the reference documentation inline with any suggestions you have with regard to making it less muddy

Cheers
Rick

[ASavitsky]

    <bean id="remoteAuthenticationService" parent="baseAuthRemoteServerService">
        <property name="serviceUrl">
            <value>${baseRmiUrl}/authenticationService</value>
        </property>
        <property name="serviceInterface">
            <value>com.tangler.service.AuthenticationService</value>
        </property>
    </bean>

How about

    <bean id="remoteAuthenticationService" parent="baseAuthRemoteServerService">
        <property name="baseUrl">
                <!-- This injects the environment String into a String property -->
                <jee:jndi-lookup jndi-name="${java:comp/env/baseRmiUrl}" />
        </property>
        <property name="relativeServiceUrl">
            <value>/authenticationService</value>
        </property>
        <property name="serviceInterface">
            <value>com.tangler.service.AuthenticationService</value>
        </property>
    </bean>

and then return the serviceUrl property as

        public String getServiceUrl() {
                return baseUrl + relativeServiceUrl;
        }

Or, better yet, set the baseUrl property in the baseAuthRemoteServerService, to do it in a centralized way?

[Dave Syer]

There's an idea. Just use the jndi lookup to fill in a property value and shove it in a placeholder. Nothing fancy:

	<bean id="configurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="properties">
			<bean class="java.util.Properties">
				<constructor-arg>
					<map>
						<entry key="baseUrl">
							<jee:jndi-lookup jndi-name="${java:comp/env/baseRmiUrl}" />
						</entry>
					</map>
				</constructor-arg>
			</bean>
		</property>
	</bean>

That should work with the original service configuration from the first post. The factory bean I mentioned earlier was really a convenient way to load in many JNDI variables, but if there are only a couple and you know their names ahead of time, you can do it this way.