Creating a Java EE application

The CICS Explorer® and IBM® CICS® SDK for Java™ help provides full details on how you can perform each of the following steps to develop and deploy applications.

1. Set up a target platform for your Java development.
   For detailed instructions, see the relevant step in Creating the JCICS examples or Creating the servlet examples.

   The target platform ensures that you use only the Java classes that are appropriate for the target release of CICS in your application development.

2. Create an OSGi Bundle Project or a plug-in project for your Java application development.
   1. The default version of the project is 1.0.0.qualifier. In the Version field either remove the .qualifier from the end of the version number, if you do not wish to use one, or set it to something meaningful, for example the date/time stamp.
   Develop your Java application using best practices; for example, to organize the dependencies between OSGi bundles, use Import-Package / Export-Package in preference to Require-Bundle.
3. If you are new to developing Java applications for CICS, you can use the examples that are provided with the IBM CICS SDK for Java to get started.
   To use JCICS in a OSGi Java application, you must import the com.ibm.cics.server package.
4. Optional: In Liberty, create a dynamic web application (WAR) or a web-enabled OSGi Bundle Project (WAB) to develop your application presentation layer.
   You can create servlets and JSP pages in a Dynamic Web Project. For a WAR file, you must also add the Liberty libraries to your build path to give you access to the Liberty API bundles. For further details, refer to Setting up the development environment.
5. Package your application for deployment:
   1. If you are deploying a web-enabled OSGi Bundle Project (WAB), create an OSGi Application Project (EBA).
   2. Create one or more CICS bundle projects to reference your EBA, your EAR file, or your web application (WAR file).
      CICS bundles are the unit of deployment for your application in CICS. Put the web applications that you want to update and manage together in a CICS bundle project. You must know the name of the JVMSERVER resource in which you want to deploy the application.

      You can also add CICS resources to the CICS bundle project, such as PROGRAM, URIMAP, and TRANSACTION resources. These resources are dynamically installed and managed with the Java application.

   3. Optional: If you want to deploy the application to a CICS platform, create an application project that references your CICS bundles.
      An application provides a single management point for deploying and managing the application across a CICSplex in CICS. For more information, see Packaging CICS applications for deployment in a cloud environment.
   4. You should always explicitly declare the packages that your OSGi bundle uses, even if the tooling does not indicate an error. You can do this by adding or updating the Import-Package bundle header in your OSGi bundle manifest. Tools such as Eclipse make assumptions about the availability of javax.* packages that might not be correct for a runtime environment where an explicit Import is necessary.
6. Deploy your Java application to zFS by exporting the application project or CICS bundle projects. Alternatively, you can save the projects in a source repository for deployment.