jbpm工作流 在任务执行过程中关闭

TaskService taskService = processEngine.getTaskService();
TopupContract topupContract = topupContractService.readTopupContract(id);
			
ExecutionService executionService = processEngine.getExecutionService();
		Task task = taskService.getTask(this.getTaskId());
			Execution execution = executionService.findExecutionById(task.getExecutionId());
			Execution processInstance = execution.getProcessInstance();
			taskService.completeTask(this.getTaskId());
			processEngine.getExecutionService().deleteProcessInstance(processInstance.getId());