Package org.camunda.bpm.application.impl

Class JakartaServletProcessApplication

java.lang.Object

org.camunda.bpm.application.AbstractProcessApplication

org.camunda.bpm.application.impl.AbstractServletProcessApplication

org.camunda.bpm.application.impl.JakartaServletProcessApplication

All Implemented Interfaces:

jakarta.servlet.ServletContextListener, EventListener, ProcessApplicationInterface

Direct Known Subclasses:

Application

public class JakartaServletProcessApplication
extends AbstractServletProcessApplication
implements jakarta.servlet.ServletContextListener

A AbstractProcessApplication Implementation to be used in a Servlet container environment.

This class implements the ServletContextListener interface and can thus participate in the deployment lifecycle of your web application.

Usage

In a Servlet 5.0 container it is sufficient adding a custom subclass of JakartaServletProcessApplication annotated with @ProcessApplication to your application:

 @ProcessApplication("Loan Approval App")
 public class LoanApprovalApplication extends ServletProcessApplication {
 // empty implementation
 }
 

This, in combination with a META-INF/processes.xml file is sufficient for making sure that the process application class is picked up at runtime.

Invocation Semantics

When the AbstractProcessApplication.execute(java.util.concurrent.Callable) method is invoked, the servlet process application modifies the context classloader of the current Thread to the classloader that loaded the application-provided subclass of this class. This allows

• the process engine to resolve JavaDelegate implementations using the classloader of the process application
• In apache tomcat this allows you to resolve Naming Resources (JNDI) form the naming context of the process application. JNDI name resolution is based on the TCCL in Apache Tomcat.

                        Set TCCL of Process Application
                                     |
                                     |  +--------------------+
                                     |  |Process Application |
                       invoke        v  |                    |
      ProcessEngine -----------------O--|--> Java Delegate   |
                                        |                    |
                                        |                    |
                                        +--------------------+

 

Process Application Reference

The process engine holds a WeakReference to the JakartaServletProcessApplication and does not cache any classes loaded using the Process Application classloader.

Field Summary

Fields

Modifier and Type	Field	Description
protected jakarta.servlet.ServletContext	servletContext

Fields inherited from class org.camunda.bpm.application.impl.AbstractServletProcessApplication

processApplicationClassloader, reference, servletContextName, servletContextPath

Fields inherited from class org.camunda.bpm.application.AbstractProcessApplication

defaultDeployToEngineName, isDeployed, processApplicationBeanElResolver, processApplicationElResolver, processApplicationScriptEnvironment, variableSerializers

Constructor Summary

Constructors

Constructor	Description
JakartaServletProcessApplication()

Method Summary

Modifier and Type	Method	Description
void	contextDestroyed(jakarta.servlet.ServletContextEvent sce)
void	contextInitialized(jakarta.servlet.ServletContextEvent sce)
jakarta.servlet.ServletContext	getServletContext()
protected ClassLoader	initProcessApplicationClassloader(jakarta.servlet.ServletContextEvent sce)

Methods inherited from class org.camunda.bpm.application.impl.AbstractServletProcessApplication

autodetectProcessApplicationName, getProcessApplicationClassloader, getProperties, getReference

Methods inherited from class org.camunda.bpm.application.AbstractProcessApplication

createDeployment, deploy, execute, execute, getBeanElResolver, getDefaultDeployToEngineName, getElResolver, getEnvironmentScripts, getExecutionListener, getName, getProcessApplicationScriptEnvironment, getRawObject, getScriptEngineForName, getTaskListener, getVariableSerializers, initProcessApplicationElResolver, setDefaultDeployToEngineName, setVariableSerializers, undeploy

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

servletContext

protected jakarta.servlet.ServletContext servletContext

Constructor Details

JakartaServletProcessApplication

public JakartaServletProcessApplication()

Method Details

contextInitialized

public void contextInitialized(jakarta.servlet.ServletContextEvent sce)

Specified by:

contextInitialized in interface jakarta.servlet.ServletContextListener

initProcessApplicationClassloader

protected ClassLoader initProcessApplicationClassloader(jakarta.servlet.ServletContextEvent sce)

contextDestroyed

public void contextDestroyed(jakarta.servlet.ServletContextEvent sce)

Specified by:

contextDestroyed in interface jakarta.servlet.ServletContextListener

getServletContext

public jakarta.servlet.ServletContext getServletContext()