user manual

Chapter 25: Implementing Partition Interceptors 268

Creating the Interceptor Class

The <priority> element is an optional field that controls the order in which a

set of interceptors for a particular Partition are fired. This value must be

between 0 and 9. Priority 0 ranks before priority 9. Interceptors are fired in

order during load time and in reverse order during shutdown. If two or more

interceptors share the same priority, there is no way to determine or enforce

which of that set will be fired relative to the other.

The <argument> is an optional element which contains a pair of elements, <key>

and <value>. These are passed into your class implementation as a

java.util.HashMap. Your code must extract the appropriate values from this

type. The limit on arguments is imposed by the JVM implementation.

For example, the following XML defines an interceptor called InterceptorImpl

<Partition-interceptor>

<class-name>com.borland.enterprise.examples.InterceptorImpl</class-

name>

<value>value1</value>

</argument>

<value>value2</value>

</argument>

<value>value3</value>

</argument>

</Partition-interceptor>

</module>

Creating the Interceptor Class

Your class must implement:

com.borland.enterprise.server.Partition.service.PartitionInterceptor

The following methods are available:

public void initialize(java.util.HashMap args);

This method is called before any Partition services like the Tomcat container

are created and initialized. This method is not subject to the <priority>

parameter, since it is invoked as each interceptor is loaded.

public void startupPreLoad();

This method is called after Partition services are started and before the

Partition services load modules.