ex9_9.txt

j2ee core design patterns

Example 9.9 	WorkflowCommandFactory Code
package ActionAdapter;

public class WorkflowCommandFactory {
  final String ACTION_MAP = "ActionMapper.xml";
  ActionMapper map;

  static private WorkflowCommandFactory me = 
      new WorkflowCommandFactory();

  protected WorkflowCommandFactory() { }

  public static WorkflowCommandFactory getInstance() {
    return me;
  }

  public WorkflowCommand createCommand(String userId,
      String workflowProcessId, String workItemId,
      String action) {

    ActionMapper mapper = new ActionMapper(ACTION_MAP);

    CommandData commandData =
        mapper.getCommandData(action,
        workflowProcessId, workItemId);

    if (commandData.getClass() == WorkflowCommandData.class) {
      return new WorkflowProcessCommand(userId, commandData);
    } else if (
        commandData.getClass() == WorkItemCommandData.class) {
      return new WorkItemCommand(userId, commandData);
    }
    return null;
  }
}