RabbitMQ学习==》路由绑定

工作路由

1、绑定2、直接交换

单个绑定：多个绑定： 3、示例

发送消息：接收消息：

​ 绑定是交换和队列之间的关系，绑定可以采用额外的routingKey参数

channel.queueBind(queueName, EXCHANGE_NAME, "black" );

绑定键的含义取决于交换类型

​ 直接交换背后的路由算法很简单——消息进入 绑定键与消息的 路由键完全匹配的队列

在这个设置中，我们可以看到绑定了两个队列的直接交换X。第一个队列使用绑定键orange进行绑定，第二个队列有两个绑定，一个使用绑定键black，另一个使用green。

在这样的设置中，使用路由键orange发布到交换的消息 将被路由到队列Q1。带有black 或 green路由键的消息将发送到Q2。所有其他消息将被丢弃

使用相同的绑定键绑定多个队列是完全合法的。在我们的示例中，我们可以使用绑定键black在X和Q1之间添加绑定。在这种情况下，直接交换的行为类似于扇出并将消息广播到所有匹配的队列。带有路由键black的消息将被传送到 Q1和Q2

    private static final String EXCHANGE_NAME = "direct_logs";

    public static void main(String[] argv) throws Exception {
        argv = new String[]{"info"};
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("192.168.6.128");
        factory.setPort(5672);
        factory.setUsername("admin");
        factory.setPassword("admin");
        try (Connection connection = factory.newConnection();
             Channel channel = connection.createChannel()) {
            channel.exchangeDeclare(EXCHANGE_NAME, "direct");

            String severity = getSeverity(argv);
            String message = getMessage(argv);
            // 发布消息，第一个参数为交换器名，第二个参数为路由键名
            channel.basicPublish(EXCHANGE_NAME, severity, null, message.getBytes("UTF-8"));
            System.out.println(" [x] Sent '" + severity + "':'" + message + "'");
        }
    }
    private static String getSeverity(String[] strings) {
        if (strings.length < 1)
            return "info";
        return strings[0];
    }

    private static String getMessage(String[] strings) {
        if (strings.length < 2)
            return "Hello World!";
        return joinStrings(strings, " ", 1);
    }

    private static String joinStrings(String[] strings, String delimiter, int startIndex) {
        int length = strings.length;
        if (length == 0) return "";
        if (length <= startIndex) return "";
        StringBuilder words = new StringBuilder(strings[startIndex]);
        for (int i = startIndex + 1; i < length; i++) {
            words.append(delimiter).append(strings[i]);
        }
        return words.toString();
    }

	private static final String EXCHANGE_NAME = "direct_logs";

    public static void main(String[] argv) throws Exception {
        argv = new String[]{"info", "warning", "error"};
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("192.168.6.128");
        factory.setPort(5672);
        factory.setUsername("admin");
        factory.setPassword("admin");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.exchangeDeclare(EXCHANGE_NAME, "direct");
        String queueName = channel.queueDeclare().getQueue();

        if (argv.length < 1) {
            System.err.println("Usage: ReceiveLogsDirect [info] [warning] [error]");
            System.exit(1);
        }

        for (String severity : argv) {
            // 将队列与交换器绑定，指定队列名、交换器、路由键名
            channel.queueBind(queueName, EXCHANGE_NAME, severity);
        }
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> { });
    }