深入探讨Spring Statemachine在Spring中实现状态机的过程

// 一个简单的状态机配置示例
statemachine<string, string> statemachine = new defaultstatemachinebuilder<string, string>()
    .state("initial")
    .state("middle")
    .state("end")
    .transition().from("initial").to("middle").on("middle_event")
    .transition().from("middle").to("end").on("end_event")
    .build();
statemachine.start();
statemachine.sendevent("middle_event");
statemachine.sendevent("end_event");

// 示例代码：状态枚举定义
public enum orderstate {
    // 基本状态
    waiting_for_payment,
    paid,
    shipped,
    completed,
    // 复合状态
    // ...
}

// 示例代码：状态转换配置
@configuration
@enablestatemachine
public class orderstatemachineconfig 
      extends statemachineconfigureradapter<orderstate, orderevent> {
    @override
    public void configure(statemachineconfigurationconfigurer<orderstate, orderevent> config) throws exception {
        config.withconfiguration()
              .autostartup(true)
              .listener(new statemachinelisteneradapter<>());
    }
    @override
    public void configure(statemachinestateconfigurer<orderstate, orderevent> states) throws exception {
        states.withstates()
              .initial(orderstate.waiting_for_payment)
              .end(***pleted)
              .states(enumset.allof(orderstate.class));
    }
    @override
    public void configure(statemachinetransitionconfigurer<orderstate, orderevent> transitions) throws exception {
        transitions.withexternal()
                   .source(orderstate.waiting_for_payment)
                   .target(orderstate.paid)
                   .event(orderevent.payment_completed);
    }
}

// 示例代码：状态转换触发
// 假设有一个方法用于处理支付事件
void processpayment(order order);
// 在处理支付完成后，触发状态转换事件
processpayment(someorder);

// 示例代码：卫兵实现
public class paymentguard implements guardian<orderstate, orderevent> {
    @override
    public boolean evaluate(statecontext<orderstate, orderevent> context) {
        order order = (order) context.getextendedstate().getvariables().get("order");
        return order.getamountdue() == order.getamountpaid();
    }
}
// 在状态转换配置中使用卫兵
transitions.withexternal()
           .source(orderstate.paid)
           .target(orderstate.shipped)
           .event(orderevent.ship_order)
           .guard(new paymentguard());

// 示例代码：动作实现
public class shippingaction implements action<orderstate, orderevent> {
    @override
    public void execute(statecontext<orderstate, orderevent> context) {
        order order = (order) context.getextendedstate().getvariables().get("order");
        // 执行发货逻辑
        shipmentservice.shiporder(order);
    }
}
// 在状态转换配置中使用动作
transitions.withexternal()
           .source(orderstate.paid)
           .target(orderstate.shipped)
           .event(orderevent.ship_order)
           .action(new shippingaction());

@configuration
@enablestatemachine
public class statemachineconfig extends statemachineconfigureradapter<string, string> {
    @override
    public void configure(statemachineconfigurationconfigurer<string, string> config)
            throws exception {
        config
            .withconfiguration()
            .autostartup(true)
            .defaultexitpointstate("s2")
            .defaultentrypointstate("s1");
    }
    @override
    public void configure(statemachinestateconfigurer<string, string> states)
            throws exception {
        states
            .withstates()
            .initial("s1")
            .state("s2")
            .end("sf");
    }
    @override
    public void configure(statemachinetransitionconfigurer<string, string> transitions)
            throws exception {
        transitions
            .withexternal()
            .source("s1").target("s2")
            .event("e1");
    }
}

@autowired
private statemachinefactory<string, string> statemachinefactory;
public statemachine<string, string> getstatemachine() {
    return statemachinefactory.getstatemachine("statemachine1");
}

public void sendevent(string event) {
    statemachine<string, string> statemachine = getstatemachine();
    statemachine.sendevent(messagebuilder.withpayload(event)
                                          .setheader(messageheaders.content_type, mimetypeutils.text_plain).build());
}

public class statemachinerunner {
    private statemachine<string, string> statemachine;
    public statemachinerunner(statemachine<string, string> statemachine) {
        this.statemachine = statemachine;
    }
    public void runstatemachine() {
        try {
            statemachine.start();
            statemachine.sendevent("e1");
            // 等待一段时间或者某个条件满足后再继续
            thread.sleep(1000);
            statemachine.sendevent("e2");
            statemachine.stop();
        } catch (exception e) {
            e.printstacktrace();
        }
    }
}

@configuration
@enablestatemachine
public class statemachineconfig extends statemachineconfigureradapter<string, string> {
    @autowired
    private statemachinepersister<string, string, context> persister;
    @override
    public void configure(statemachinepersister<string, string, context> persister) {
        this.persister = persister;
    }
    // 配置状态机状态等其他必要的配置
}

graph lr;
    a[开始事务]
    b[服务a准备]
    c[服务b准备]
    d[服务a提交]
    e[服务b提交]
    f[事务结束]
    a --> b
    a --> c
    b --> d
    c --> e
    d --> f
    e --> f

public class customstatelistener implements statelistener {
    @override
    public void statechanged(state fromstate, state tostate) {
        // 从状态fromstate变化到状态tostate
        system.out.println("state change from " + fromstate.getid() + " to " + tostate.getid());
    }
}

public class customactionlistener implements actionlistener {
    @override
    public void onaction(action action, transition transition) {
        if ("send_email".equals(action.getid())) {
            system.out.println("sending email as an action is performed");
        }
    }
}

public class compositelistener implements statelistener, actionlistener {
    @override
    public void statechanged(state fromstate, state tostate) {
        // 状态变化处理逻辑
    }
    @override
    public void onaction(action action, transition transition) {
        // 动作执行处理逻辑
    }
}

public class inventoryupdatelistener implements statelistener {
    @override
    public void statechanged(state fromstate, state tostate) {
        if (tostate.getid().equals("payment_success")) {
            // 执行库存更新操作
            system.out.println("updating inventory as payment succeeded");
        }
    }
}

@springbootapplication
@enablestatemachine
public class application {
    public static void main(string[] args) {
        springapplication.run(application.class, args);
    }
    @bean
    public statemachineconfigurationconfigurer<states, events> configurer() {
        return config -> config
                .withconfiguration()
                .autostartup(true)
                .listener(new mystatemachinelistener());
    }
    // 其他配置代码...
}

statemachine:
  states:
    - 'state1'
    - 'state2'
  events:
    - 'event1'
    - 'event2'
  transitions:
    - source: 'state1'
      target: 'state2'
      event: 'event1'
  autostartup: true

@configuration
@enablestatemachinesecurity
public class securityconfig extends statemachineconfigureradapter<string, string> {
    @override
    public void configure(statemachinesecurityconfigurer<string, string> security) throws exception {
        security
            .withsecurity()
            .runtimeaccess()
            .roles("admin")
            .and()
            .authorize("hasrole('admin')")
            .anystate()
            .anyevent();
    }
    // 其他配置代码...
}

@entity
public class statemachineentity {
    @id
    @generatedvalue(strategy = generationtype.auto)
    private long id;
    // 其他字段和方法...
}
public interface statemachinerepository extends jparepository<statemachineentity, long> {
    // 自定义查询操作...
}
// 在状态机配置中引用statemachinerepository...

// 示例代码：简单状态机配置
@configuration
@enablestatemachine
public class simplestatemachineconfig extends statemachineconfigureradapter<string, string> {
    @override
    public void configure(statemachineconfigurationconfigurer<string, string> config) throws exception {
        config.withconfiguration()
              .autostartup(true)
              .defaulttransactionmode(defaulttransactionmode.support);
    }
    @override
    public void configure(statemachinestateconfigurer<string, string> states) throws exception {
        states.withstates()
              .initial("si")
              .end("sf")
              .states(enumset.allof(mystate.class));
    }
    @override
    public void configure(statemachinetransitionconfigurer<string, string> transitions) throws exception {
        transitions.withexternal()
                   .source("si").target("s1")
                   .event("e1")
                   .and()
                   .withexternal()
                   .source("s1").target("sf")
                   .event("e2");
    }
}