8 Creating a Session Persistence Module

GlassFish Server enables you to create a session persistence module in the web container for high availability-related functionality by implementing the PersistenceStrategyBuilder interface . Using the PersistenceStrategyBuilder interface in an HK2 service makes the session manager extensible because you can implement a new persistence type without having to modify the web container code.

For information about other high-availability, session persistence solutions, see "Configuring High Availability Session Persistence and Failover" in Oracle GlassFish Server High Availability Administration Guide.

Implementing the `PersistenceStrategyBuilder` Interface

You can implement the PersistenceStrategyBuilder interface by creating a new web session manager type.

package com.sun.enterprise.web;

import com.sun.enterprise.deployment.runtime.web.SessionManager;
import org.apache.catalina.Context;
import org.jvnet.hk2.annotations.Contract;

@Contract
public interface PersistenceStrategyBuilder {
    
    public void initializePersistenceStrategy(
            Context ctx,
            SessionManager smBean,
            ServerConfigLookup serverConfigLookup);

    public void setPersistenceFrequency(String persistenceFrequency);

    public void setPersistenceScope(String persistenceScope);

    public void setPassedInPersistenceType(String persistenceType);
}

Here is an example of how to implement the PersistenceStrategyBuilder interface by creating a new web session manager and setting a store for it:

@Service(name="xyz")
public class XYZStrategyBuilder implements PersistenceStrategyBuilder {

    private String persistenceFrequency = null;
    private String persistenceScope = null;
    private String persistenceType = null;
 
    public void init(StandardContext ctx, SessionManager sessionManager,
      ServerConfigLookup serverConfigLookup) {
        // add listeners, valves, etc. to the ctx
        // Set the manager and store
    }
 
    public void setPersistenceFrequency(String persistenceFrequency) {
        this.persistenceFrequency = persistenceFrequency;
    }
    
    public void setPersistenceScope(String persistenceScope) {
        this.persistenceScope = persistenceScope;
    }
        
    public void setPassedInPersistenceType(String persistenceType) {
        this.passedInPersistenceType = persistenceType;
    }
}

If a Manager is provided, then it will be used in GlassFish Server.

Note:

If a backing store is required, it is the responsibility of the Manager to make sure that the findSession method correctly uses the Store that the Manager provides.

Example 8-1 Implementing PersistenceStrategyBuilder With a Custom Web Session Manager

This example defines a session manager type that is named MyHASolution.

@Service(name="MyHASolution")
public class MyHASolutionStrategyBuilder implements PersistenceStrategyBuilder {

    private String persistenceFrequency = null;
    private String persistenceScope = null;
    private String persistenceType = null;

    public void init(StandardContext ctx, SessionManager sessionManager,
      ServerConfigLookup serverConfigLookup) {
        // add listeners, valves, etc. to the ctx
        // Set the manager and store
        MyManager myManager = new MyManager(persistenceType, persistenceFrequency); 
        // (You could also make this a service and look it up in the habitat. 
        // For simplicity we are just doing a new implementation of the class here.)
        MyStore store = new MyStore();
        myManager.setStore(store);
        ctx.setManager(myManager);
    }

    public void setPersistenceFrequency(String persistenceFrequency) {
        this.persistenceFrequency = persistenceFrequency;
    }
    
    public void setPersistenceScope(String persistenceScope) {
        this.persistenceScope = persistenceScope;
    }
        
    public void setPassedInPersistenceType(String persistenceType) {
        this.passedInPersistenceType = persistenceType;

    }

}

Example 8-2 Session Manager Configuration in the glassfish-web.xml File

This example sets the persistence-type attribute of the session-manager element of glassfish-web.xml to myHASolution

Based on the domain.xml and glassfish-web.xml settings, the web container looks up the appropriate PersistenceStrategyBuilder interface in the Habitat and uses it.

<glassfish-web-app>
         <session-config>
           <session-manager persistence-type="myHASolution"/>
         <session-config>
       <glassfish-web-app>

8 Creating a Session Persistence Module

Implementing the PersistenceStrategyBuilder Interface

Implementing the `PersistenceStrategyBuilder` Interface