Releasing Resources

When tasks process, they use resources such as files, database connections, or queue connection factories. When processing is completed or during errors, before the task returns control to the Services Framework, it is required to release any resources it used. Releasing resources ensures no memory leaks and the JVM (Java™ Virtual Machine) runs cleanly. An exception to releasing resources is to not have the custom task perform a database close on the connection passed to it. For example, the Java code must not perform the following:

connect.close(); // Close Database connection called connect

The Base Task requires the task to implement a releaseResources() method.

public  void  releaseResources();

When the task finishes processing, it should always call the releaseResources() method before returning control to the Services Framework. The Services Framework also calls the releaseResources() method after processing, which prevents custom tasks from leaving resources open.

Example

If a task writes to a file and a WebSphere® MQ queue, it is recommended for the releaseResources() method to be used. This ensures all file and MQ resources are cleaned up. A code example is shown here:

public void releaseResources()
{
  if (fileOutputStream != null) {
     fileOutputStream.close();
     fileOutputStream = null;
  }
  if (mqSession != null) {
     mqSession.close();
     mqSession = null;
  }
  if (mqConnection != null) {
     mqConnection.close();
     mqConnection = null;
  }
}

Refer to the Javadoc information for additional information about methods and signatures.