Application Environment Entries

Environment entries, defined using <env-entry>, provide a way of specifying deployment time parameters to J2SE Web applications. Note that the servlet context initialization parameters could be defined using <context-param>, but <env-entry> is the preferred way because application deployers to configure such applications parameters by explicitly specifying the name, type and values for them.

The following sample describes the syntax of <env-entry> as specified in the J2SE standard deployment descriptors:

<env-entry>
<description> Send pincode by mail </description>
<env-entry-name> mailPincode </env-entry-name>
<env-entry-value> false </env-entry-value>
<env-entry-type> java.lang.Boolean </env-entry-type>
</env-entry>

The <env-entry-type> tag specifies a fully qualified class name for the entry. Here is a code snippet to lookup the <env-entry> using JNDI from a servlet or JSP:

Context initContext = new InitialContext();
Boolean mailPincode = (Boolean)
initContext.lookup("java:comp/env/mailPincode");
// one could use relative names into the sub-context
Context envContext = initContext.lookup("java:comp/env");
Boolean mailPincode = (Boolean)
envContext.lookup("mailPincode");