Spring基于状态机squirrel-foundation简单使用

squirrel-foundation的一些使用方法在百度上资料还是比较少，我是根据以下三个大佬写的文章借鉴的，在这里记录一下。
1、squirrel-foundation-demo
2、Squirrel使用（中文文档）
3、squirrel-foundation状态机的使用细节
我在这里直接粘贴代码，便于自己之后理解。

1. /**

2. * 通过Spring创建StateMachineBuilder实例，通过buidler创建状态机(单例)

3. * 创建无类型化状态机，简化状态机，防止过多泛化导致代码不易阅读(因为不太理解一些高级的使用)

4. */

5. public abstract class AbstractStateMachineEngine <T extends UntypedStateMachine> implements ApplicationContextAware {

6.  

7. private ApplicationContext applicationContext;

8.  

9. protected UntypedStateMachineBuilder stateMachineBuilder = null;

10.  

11. @SuppressWarnings("unchecked")

12. public AbstractStateMachineEngine() {

13. //识别泛型参数

14. Class<T> genericType = (Class<T>) GenericTypeResolver.resolveTypeArgument(getClass(),

15. AbstractStateMachineEngine.class);

16. stateMachineBuilder = StateMachineBuilderFactory.create(genericType, ApplicationContext.class);

17. }

18.  

19. //注入applicationContext，并在创建StateMachine实例时注入

20. @Override

21. public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

22. this.applicationContext = applicationContext;

23. }

24.  

25. /**

26. * 可以通过向OrderContext 上下文传递一些业务参数，比如orderId等等

27. */

28. public boolean fire(EOrderEvents event, OrderContext context) {

29. T stateMachine = stateMachineBuilder.newUntypedStateMachine(

30. context.geteOrder().getOrderStatus(),

31. applicationContext);

32.  

33. //由于StateMachine实例不是由Spring容器创建，所以这个过程中无法通过注解方式开启事务(Spring没有机会去创建事务代理)，因此采用了编程式事务

34. DataSourceTransactionManager transactionManager = (DataSourceTransactionManager)applicationContext.getBean("transactionManager");

35. DefaultTransactionDefinition def = new DefaultTransactionDefinition();

36. def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);

37. TransactionStatus status = transactionManager.getTransaction(def);

38. try {

39. stateMachine.fire(event, context);

40. transactionManager.commit(status);

41. //这里会返回状态机是否出错，如果出错可用于通知Controller层，目前只会这样简单的操作

42. return stateMachine.isError();

43. } catch (Exception ex) {

44. //用于事务回滚

45. transactionManager.rollback(status);

46. return true;

47. }

48. }

49. }

1. /**

2. * 该类相当于监听状态变化，构造一些监听方法实现一些逻辑代码

3. * @States 定义状态列表，里面可以包含多个状态

4. * @State定义每个状态，name状态名称，entryStateInit进入状态时调用的方法，exitCallMethod 离开状态是调用的方法，initialState 为true时，为默认状态。

5. * */

6. @States({

7. @State(name = "UNFOUND", entryCallMethod = "entryStateInit", exitCallMethod = "exitStateInit", initialState = true),

8. @State(name = "USING", entryCallMethod = "entryStateWaitPay", exitCallMethod = "exitStateWaitPay"),

9. @State(name = "COMPLETE", entryCallMethod = "entryStateWaitSend", exitCallMethod = "exitStateWaitSend"),

10. @State(name = "REFUND", entryCallMethod = "entryStatePartSend", exitCallMethod = "exitStatePartSend"),

11. @State(name = "NOUSE", entryCallMethod = "entryStatePartSend", exitCallMethod = "exitStatePartSend")

12. })

13. @Transitions({

14. @Transit(from = "UNFOUND", to = "UNFOUND", on = "FOUND", callMethod = "createOrder"),

15. @Transit(from = "UNFOUND", to = "USING", on = "SAOMA", callMethod = "submitOrder"),

16. @Transit(from = "USING", to = "COMPLETE", on = "PAY", callMethod = "pay"),

17. @Transit(from = "USING", to = "REFUND", on = "USING_REFUNDING", callMethod = "usingRefund"),

18. @Transit(from = "COMPLETE", to = "REFUND", on = "COM_REFUNDING", callMethod = "comRefund")

19. })

20. //该地方向AbstractStateMachine传递的参数

21. @StateMachineParameters(stateType = OrderStates.class, eventType = OrderEvents.class, contextType = OrderContext.class)

22. public class SubmitOrderStateMachine extends AbstractStateMachine<UntypedStateMachine, Object, Object, Object> implements UntypedStateMachine {

23.  

24. private OrderService OrderService;

25. protected ApplicationContext applicationContext;

26.  

27. //定义构造函数接受ApplicationContext注入([参看New State Machine Instance](http://hekailiang.github.io/squirrel/))

28. public SubmitOrderStateMachine(ApplicationContext applicationContext) {

29. this.applicationContext = applicationContext;

30. // 通过applicationContext注入orderService，这样就可以通过service操作数据库

31. OrderService = (OrderService) this.applicationContext.getBean("OrderService");

32. }

33.  

34. //创建订单，依旧处于待使用状态

35. public void createOrder(OrderStates fromState, OrderStates toState, OrderEvents OrderEvents, OrderContext OrderContext) {

36. //可以做一些创建订单等等操作

37. }

38.  

39. //提交订单

40. public void submitOrder(OrderStates fromState, OrderStates toState, OrderEvents OrderEvents, OrderContext OrderContext) {

41. }

42.  

43. //支付订单

44. public void pay(OrderStates fromState, OrderStates toState, OrderEvents OrderEvents, OrderContext OrderContext) {

45. }

46.  

47. public void usingRefund(OrderStates fromState, OrderStates toState, OrderEvents OrderEvents, OrderContext OrderContext) {

48. }

49.  

50. public void comRefund(OrderStates fromState, OrderStates toState, OrderEvents OrderEvents, OrderContext OrderContext) {

51. }

52.  

53. /**

54. * 如果实现这个方法，当上面方法执行出现错误时就会转到这里来执行。

55. * 但是由于自己是菜鸟，并不知道出错后这里该如何通知到Controller层

56. * 因此这里并未实现，具体的实现方法请参考官网

57. */

58. /*

59. @Override

60. protected void afterTransitionCausedException(Object fromState, Object toState, Object event, Object context) {

61. //super.afterTransitionCausedException(fromState, toState, event, context);

62. }*/

63. }

还需要一个类集成AbstractStateMachineEngine，用于调用fire()方法。该类需要添加@Service注解，以便spring注入

1. @Service

2. public class OrderStateMachineEngine extends AbstractStateMachineEngine<SubmitOrderStateMachine>{

3.  

4. }

Controller层使用：

1. /**

2. * 这里需要加上try**catch**，以便发生错误可方便执行下去

3. */

4. @RequestMapping(value="/modOrderStatus",method = {RequestMethod.POST})

5. @ResponseBody

6. public ResultEntity<Order> modOrderStatus(@RequestParam("event") String event,int code,Long orderId){

7. ResultEntity<Order> resultEntity = new ResultEntity<Order>();

8. try {

9. Order Order = new Order();

10. Order.setOrderStatus(OrderStates.getState(code));

11. //向订单上下文可添加一些逻辑参数，如：orderId

12. OrderContext OrderContext = new OrderContext(Order, orderId);

13. if(!orderStateMachineEngine.fire(OrderEvents.getEvent(event), OrderContext)) {

14. resultEntity.setCode(1);

15. resultEntity.setMessage("成功!");

16. }else {

17. resultEntity.setCode(0);

18. resultEntity.setMessage("更新失败，请重新尝试!");

19. }

20. return resultEntity;

21. } catch (Exception e) {

22. e.printStackTrace();

23. log.error(e);

24. resultEntity.setCode(0);

25. resultEntity.setMessage("更新失败，请重新尝试!");

26. return resultEntity;

27. }

28. }

OrderContext类：

1. /**

2. * 订单上下文

3. * */

4. public class OrderContext {

5.  

6. public OrderContext(Order eOrder,Long orderId) {

7. this.Order = Order;

8. this.orderId = orderId;

9. }

10.  

11. public OrderContext() {

12. }

13.  

14. private Order Order;

15. //逻辑参数

16. private Long orderId;

17.  

18. public Order getOrder() {

19. return Order;

20. }

21.  

22. public void seteOrder(Order Order) {

23. this.Order = Order;

24. }

25.  

26. public Long getOrderId() {

27. return orderId;

28. }

29.  

30. public void setOrderId(Long orderId) {

31. this.orderId = orderId;

32. }

33. }

OrderEvents枚举:

1.  

2. /**

3. * 订单状态转变事件

4. * */

5. public enum OrderEvents {

6. FOUND, //创建订单

7. SAOMA, //提交订单

8. PAY, //付款

9. USING_REFUNDING,

10. COM_REFUNDING;

11.  

12. public static OrderEvents getEvent(String event) {

13. for (OrderEvents orderEvent : OrderEvents.values()) {

14. if (orderEvent.name().equals(event)) {

15. return orderEvent;

16. }

17. }

18. return null;

19. }

20. }

OrderStatus枚举：

1. /**

2. * 订单状态

3. * */

4. public enum OrderStates implements IEnum<Integer>{

5.  

6. UNFOUND(1,"待使用"),

7. USING(2,"正使用"),

8. COMPLETE(3,"已完成"),

9. REFUND(4,"退款"),

10. NOUSE(5,"放弃订单");

11.  

12. private String desc;

13. private int code;

14.  

15. private OrderStates(int code,String desc) {

16. this.code = code;

17. this.desc = desc;

18. }

19.  

20. public String getDesc() {

21. return desc;

22. }

23. public void setDesc(String desc) {

24. this.desc = desc;

25. }

26.  

27. public int getCode() {

28. return code;

29. }

30. public void setCode(int code) {

31. this.code = code;

32. }

33.  

34. public static OrderStates getState(int code) {

35. for (OrderStates orderState : OrderStates.values()) {

36. if (orderState.ordinal()+1 == code) {

37. return orderState;

38. }

39. }

40. return null;

41. }

42.  

43. /**

44. * 实现IEnum接口重写的该方法

45. * 该方法的作用就是表示返回的值，将要存储在数据库中

46. * 和EnumValue注解作用一样，在字段上EnumValue，就可不需要实现IEnum接口

47. * */

48. @Override

49. public Integer getValue() {

50. // TODO Auto-generated method stub

51. return code;

52. }

53.