可以看到，每次进行状态流转时，检查checkCondition()，当返回true，执行状态流转的操作doAction()。5zq拜客生活常识网

后面所有的checkCondition()和doAction()方法在下方就不再重复贴出了。5zq拜客生活常识网

2. 从多个状态流传到新的状态

@Test
public void testExternalTransitionsNormal(){
    StateMachineBuilder builder = StateMachineBuilderFactory.create();
    builder.externalTransitions()
            .fromAmong(States.STATE1, States.STATE2, States.STATE3)
            .to(States.STATE4)
            .on(Events.EVENT1)
            .when(checkCondition())
            .perform(doAction());

    StateMachine stateMachine = builder.build(MACHINE_ID+"1");
    States target = stateMachine.fireEvent(States.STATE2, Events.EVENT1, new Context());
    Assert.assertEquals(States.STATE4, target);
}

3. 状态内部触发流转

@Test
public void testInternalNormal(){
    StateMachineBuilder builder = StateMachineBuilderFactory.create();
    builder.internalTransition()
            .within(States.STATE1)
            .on(Events.INTERNAL_EVENT)
            .when(checkCondition())
            .perform(doAction());
    StateMachine stateMachine = builder.build(MACHINE_ID+"2");

    stateMachine.fireEvent(States.STATE1, Events.EVENT1, new Context());
    States target = stateMachine.fireEvent(States.STATE1, Events.INTERNAL_EVENT, new Context());
    Assert.assertEquals(States.STATE1, target);
}

4. 多线程测试并发测试

@Test
public void testMultiThread(){
 buildStateMachine("testMultiThread");

  for(int i=0 ; i<10 ; i++){
   Thread thread = new Thread(()->{
      StateMachine stateMachine = StateMachineFactory.get("testMultiThread");
      States target = stateMachine.fireEvent(States.STATE1, Events.EVENT1, new Context());
      Assert.assertEquals(States.STATE2, target);
      });
      thread.start();
    }


    for(int i=0 ; i<10 ; i++) {
      Thread thread = new Thread(() -> {
      StateMachine stateMachine = StateMachineFactory.get("testMultiThread");
      States target = stateMachine.fireEvent(States.STATE1, Events.EVENT4, new Context());
      Assert.assertEquals(States.STATE4, target);
      });
      thread.start();
    }

    for(int i=0 ; i<10 ; i++) {
      Thread thread = new Thread(() -> {
      StateMachine stateMachine = StateMachineFactory.get("testMultiThread");
      States target = stateMachine.fireEvent(States.STATE1, Events.EVENT3, new Context());
      Assert.assertEquals(States.STATE3, target);
      });
      thread.start();
  }

}

由于COLA状态机时无状态的状态机，所以性能是很高的。相比起来，SpringStateMachine由于是有状态的，就需要使用者自行保证线程安全了。5zq拜客生活常识网

二、多分支状态流转示例

/**
* 测试选择分支，针对同一个事件：EVENT1
* if condition == "1", STATE1 --> STATE1
* if condition == "2" , STATE1 --> STATE2
* if condition == "3" , STATE1 --> STATE3
*/
@Test
public void testChoice(){
  StateMachineBuilder builder = StateMachineBuilderFactory.create();
  builder.internalTransition()
  .within(StateMachineTest.States.STATE1)
  .on(StateMachineTest.Events.EVENT1)
  .when(checkCondition1())
  .perform(doAction());
  builder.externalTransition()
  .from(StateMachineTest.States.STATE1)
  .to(StateMachineTest.States.STATE2)
  .on(StateMachineTest.Events.EVENT1)
  .when(checkCondition2())
  .perform(doAction());
  builder.externalTransition()
  .from(StateMachineTest.States.STATE1)
  .to(StateMachineTest.States.STATE3)
  .on(StateMachineTest.Events.EVENT1)
  .when(checkCondition3())
  .perform(doAction());

  StateMachine