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8.4. Running JBoss Cache in the JBoss Application server

JBoss Cache uses JGroups as a transport layer. More information on JGroups can be found on Chapter 10, JGroups

In the JBoss Application Server 5, JBoss cache runs in the all configuration of the application server(i.e <JBOSS_HOME>/server/all). All you need to do is start the server with this configuration.

            <JBOSS_HOME>/bin/./run.sh -c all

All required jars will be on the classpath. Otherwise, you will need to ensure jbosscache.jar and jgroups-all.jar are on the classpath. You may need to add other jars if you're using things like JdbmCacheLoader. The simplest way to do this is to copy the jars from the JBoss Cache distribution's lib directory to the server configurations all lib directory. You could also package the jars with the configuration file in Service Archive (.sar) file or an EAR.

It is possible to deploy a JBoss Cache 2.0 instance in JBoss AS 4.x (at least in 4.2.0.GA; other AS releases are completely untested). However, the significant API changes between the JBoss Cache 2.x and 1.x releases mean none of the standard AS 4.x clustering services (e.g. http session replication) that rely on JBoss Cache will work with JBoss Cache 2.x. Also, be aware that usage of JBoss Cache 2.x in AS 4.x is not something the JBoss Cache developers are making any significant effort to test, so be sure to test your application well (which of course you're doing anyway.)

Note in the http://labs.jboss.com/file-access/default/members/jbosscache/freezone/docs/2.1.0.GA/userguide_en/html_single/index.html#sample_xml_file the value of the mbean element's code attribute: org.jboss.cache.jmx.CacheJmxWrapper . This is the class JBoss Cache uses to handle JMX integration; the Cache itself does not expose an MBean interface. See the JBoss Cache MBeans section for more on the CacheJmxWrapper .

Once your cache is deployed, in order to use it with an in-VM client such as a servlet, a JMX proxy can be used to get a reference to the cache:

MBeanServer server = MBeanServerLocator.locateJBoss();

ObjectName on = new ObjectName("jboss.cache:service=Cache");

CacheJmxWrapperMBean cacheWrapper =
  (CacheJmxWrapperMBean) MBeanServerInvocationHandler.newProxyInstance(server, on,
  CacheJmxWrapperMBean.class, false);
    Cache cache = cacheWrapper.getCache();
    Node root = cache.getRoot(); // etc etc

The MBeanServerLocator class is a helper to find the (only) JBoss MBean server inside the current JVM. The javax.management.MBeanServerInvocationHandler class' newProxyInstance method creates a dynamic proxy implementing the given interface and uses JMX to dynamically dispatch methods invoked against the generated interface to the MBean. The name used to look up the MBean is the same as defined in the cache's configuration file.

Once the proxy to the CacheJmxWrapper is obtained, the getCache() will return a reference to the Cache itself.