Java EE 7 SDK

The Executor Concurrency Sample Application

This sample demonstrates how to use javax.enterprise.concurrent.ManagedExecutorService for submitting tasks.

Description

The demo contains a collection of servlets that show how to use methods from the ManagedExecutorService interface to submit tasks to be processed asynchronously.

All the sample servlets in this demo use the default ManagedExecutorService as defined in the Concurrency Utilities for Java EE 1.0 specification which is available in all compliant Java EE Products. Thus no special configuration is required.

The following is a list of servlets included in this demo:

URI pattern	Description
/TestResourceServlet	Submit tasks using a `ManagedExecutorService` retrieved using `@Resource` in a servlet, using the `execute()` and `submit()` methods.
/TestJNDIServlet	Submit tasks using a `ManagedExecutorService` retrieved using JNDI lookup in a servlet, using the `execute()` and `submit()` methods.
/TestEJBServlet	Submit tasks using a `ManagedExecutorService` in an EJB session bean, using the `sumbit()` method.
/TestInvokeAllServlet	Submit a collection of tasks using the `invokeAll()` method in `ManagedExecutorService`, and wait for all tasks to complete.
/TestInvokeAnyServlet	Submit a collection of tasks using the `invokeAny()` method in `ManagedExecutorService`, and wait for the first task to complete.
/TestListenerServlet	Submit a `ManagedTask` with a `ManagedTaskListener` to receive task lifecycle callbacks.
/TestTransactionServlet	Submit tasks that make use of `javax.transaction.UserTransaction`.

The application is built and deployed as a WAR file.

Key Features

Lookup of ManagedExecutorService from servlets and EJBs
Use of the submit(), execute(), invokeAll(), invokeAny() methods in ManagedExecutorService
Use of ManagedTaskListener to receive task lifecycle notifications
Perform JNDI lookup from a task
Transaction demarcation using javax.transaction.UserTransaction from a task

Building, Deploying, and Running the Application

Perform the following steps to build, deploy, and run the application:

Set up your build environment and configure the application server with which the build system has to work by following the common build instructions.
samples_install_dir is the sample application base directory. Go to: samples_install_dir/javaee7/concurrency/executor.
Build, deploy, and run the sample application using the run outcome.
mvn clean verify cargo:run
The front page of this sample is at http://localhost:8080/executor
(the port number might vary).
Use the clean outcome to undeploy the sample application and to remove the temporary directories such as build and dist.
mvn clean

Troubleshooting

If you have problems when running the application, refer to the troubleshooting document.