guava event

evevntbus 负责register和post event.

public class TradeAuditor {

    @Subscribe
    @AllowConcurrentEvents
    public void auditTrade(TradeAccountEvent tradeAccountEvent) {
        System.out.println("thread" + Thread.currentThread().getName());
        System.out.println("recive event");
    }

    public TradeAuditor(EventBus eventBus) {
        eventBus.register(this);
    }
}


在register中，会解析subscribe注解对应的函数为event的handler.@AllowConcurrentEvents表明这个handler是同步的。

public class TradeExcutor {

    private EventBus eventBus;
    public TradeExcutor(EventBus eventBus) {
        this.eventBus = eventBus;
    }

    public void executeTrade(double amount) {
        TradeAccountEvent tradeAccountEvent = new TradeAccountEvent(amount, new Date());
        System.out.println("post event");
        eventBus.post(tradeAccountEvent);
    }
}

在post event,会找到这个event对应的handler,调用，这里没有异步调用，并且会让上一次的handler执行完成后才执行下一个handler.