Configuring an Environment Reference to an Environment Variable

You can create environment variables that your bean accesses through a JNDI lookup on the InitialContext. These variables are defined within an ejb-jar.xml file <env-entry> element and can be of the following types: String, Integer, Boolean, Double, Byte, Short, Long, and Float. The environment variable name is defined in the <env-entry-name> subelement, the type is defined in the <env-entry-type> subelement, and the value is defined in the <env-entry-value> subelement. The <env-entry-name> is relative to the "java:comp/env" context.

Example 19-17 shows how to define environment variables for java:comp/env/minBalance and java:comp/env/maxCreditBalance in the ejb-jar.xml file.

Example 19-17 ejb-jar.xml For Environment Variables

<env-entry>
     <env-entry-name>minBalance</env-entry-name>
     <env-entry-type>java.lang.Integer</env-entry-type>
     <env-entry-value>500</env-entry-value>
</env-entry>
<env-entry>
     <env-entry-name>maxCreditBalance</env-entry-name>
     <env-entry-type>java.lang.Integer</env-entry-type>
     <env-entry-value>10000</env-entry-value>
</env-entry>

You can override an environment variable value defined in the ejb-jar.xml file by defining an env-entry-mapping element in your orion-ejb-jar.xml file, whose name attribute matches the env-entry-name defined in the ejb-jar.xml file. The type specified in the ejb-jar.xml file stays the same.

Figure 19-7 shows how the minBalance environment variable value is overridden by the orion-ejb-jar.xml file and set to 500.

Figure 19-7 Overriding Environment Variables in ejb-jar.xml with orion-ejb-jar.xml

Description of "Figure 19-7 Overriding Environment Variables in ejb-jar.xml with orion-ejb-jar.xml"

For more information on looking up environment variables, see the following:

"Looking Up an EJB 3.0 Environment Variable"

"Looking Up an EJB 2.1 Enviornment Variable"