//备份队列

    @Bean("alternate_queue")

    public Queue alternate_queue() {

        return new Queue("alternate_queue", true);

    }

 //备份交换机

    @Bean("alternate_exchange")

    public TopicExchange alternate_exchange() {

        return new TopicExchange("alternate_exchange", true, false);

    }

 //备份队列

    @Bean("backBinding")

    public Binding backBinding(@Qualifier("alternate_queue") Queue third,@Qualifier("alternate_exchange")TopicExchange exchange) {

        return BindingBuilder.bind(third).to(exchange).with("#");//备份交换机是无条件的路由键

    }

    //给自己留一个备份交换机  alternate_exchange

    @Bean("firstExchange")

    public FanoutExchange firstExchange() {

        //声明交换机的时候指定备份交换机

        Map<String,Object> arguments=new HashMap<>();

        arguments.put("alternate-exchange","alternate_exchange");

        return new FanoutExchange("firstExchange", true, false,arguments);

    }

    @Bean("firstBinding")

    public Binding firstBinding(@Qualifier("first") Queue first,@Qualifier("firstExchange")FanoutExchange exchange) {

        return BindingBuilder.bind(first).to(exchange);

    }

    @Bean("first")

    public Queue first() {

        return new Queue("first", true);

    }