statefulflow - 有状态计算应用示例

示例（两种接口使用对比）

public class NotBlockStateFlowDemo {
    NotBlockStateController stateController = new NotBlockStateController();
    InMemoryStateRepository stateRepository = new InMemoryStateRepository() {
        @Override
        public void statePut(FlowContext context, Node node, StateType state) {
            super.statePut(context, node, state);
            //todo: 打印放这儿，顺序更真实
            if (state == StateType.COMPLETED) {
                log.info("{} 完成", node.getId());
            }
        }
    };

    @Test
    public void useEval() {
        //计算后，不能获取最新状态

        FlowEngine flowEngine = FlowEngine.newInstance();
        Chain chain = getChain();

        FlowContext context = FlowContext.of("5", stateController, stateRepository)
                .put("tag", "");

        flowEngine.eval(chain, context);
        System.out.println("--------------------");

        context = FlowContext.of("6", stateController, stateRepository)
                .put("tag", "n1");
        flowEngine.eval(chain, context);
        System.out.println("--------------------");

        //再跑（仍在原位、原状态）
        flowEngine.eval(chain, context);
        System.out.println("--------------------");


        context.put("tag", "n2");
        flowEngine.eval(chain, context);
        System.out.println("--------------------");

        context.put("tag", "");
        flowEngine.eval(chain, context);
        System.out.println("--------------------");
    }

    @Test
    public void useFlowStatefulService() {
        //计算后，可获取最新状态

        FlowEngine flowEngine = FlowEngine.newInstance();
        FlowStatefulService statefulService = flowEngine.statefulService();
        Chain chain = getChain();

        FlowContext context = FlowContext.of("3", stateController, stateRepository)
                .put("tag", "");

        StatefulTask task = statefulService.getTask(chain, context);
        System.out.println("--------------------");
        Assertions.assertNotNull(task);
        Assertions.assertEquals("n3", task.getNode().getId());
        Assertions.assertEquals(StateType.COMPLETED, task.getState());

        context = FlowContext.of("4", stateController, stateRepository)
                .put("tag", "n1");

        task = statefulService.getTask(chain, context);
        System.out.println("--------------------");
        Assertions.assertNotNull(task);
        Assertions.assertEquals("n1", task.getNode().getId());
        Assertions.assertEquals(StateType.WAITING, task.getState());

        //再跑（仍在原位、原状态）
        task = statefulService.getTask(chain, context);
        System.out.println("--------------------");
        Assertions.assertNotNull(task);
        Assertions.assertEquals("n1", task.getNode().getId());
        Assertions.assertEquals(StateType.WAITING, task.getState());


        context.put("tag", "n2");

        task = statefulService.getTask(chain, context);
        System.out.println("--------------------");
        Assertions.assertNotNull(task);
        Assertions.assertEquals("n2", task.getNode().getId());
        Assertions.assertEquals(StateType.WAITING, task.getState());

        context.put("tag", "");

        task = statefulService.getTask(chain, context);
        System.out.println("--------------------");
        Assertions.assertNotNull(task);
        Assertions.assertEquals("n3", task.getNode().getId());
        Assertions.assertEquals(StateType.COMPLETED, task.getState());
    }

    private Chain getChain() {
        Chain chain = new Chain("tmp-" + System.currentTimeMillis());

        String task = "if(tag.equals(node.getId())){exchanger.interrupt();}";

        chain.addNode(NodeDecl.startOf("s").linkAdd("n0"));
        chain.addNode(NodeDecl.activityOf("n0").task(task).linkAdd("n1"));
        chain.addNode(NodeDecl.activityOf("n1").task(task).linkAdd("n2"));
        chain.addNode(NodeDecl.activityOf("n2").task(task).linkAdd("n3"));
        chain.addNode(NodeDecl.activityOf("n3").task(task).linkAdd("e"));
        chain.addNode(NodeDecl.endOf("e"));

        return chain;
    }
}

打印样列

INFO 2025-08-17 17:33:40.711 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n0 完成
INFO 2025-08-17 17:33:40.712 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n1 完成
INFO 2025-08-17 17:33:40.712 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n2 完成
INFO 2025-08-17 17:33:40.712 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n3 完成
--------------------
INFO 2025-08-17 17:33:40.716 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n0 完成
--------------------
--------------------
INFO 2025-08-17 17:33:40.716 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n1 完成
--------------------
INFO 2025-08-17 17:33:40.717 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n2 完成
INFO 2025-08-17 17:33:40.717 #15134 [-main] features.flow.stateful.NotBlockStateFlowTest2#console: 
n3 完成
--------------------