RabbitMQ-exchangeDeclare

创建一个交换器

 ConnectionFactory connectionFactory = new ConnectionFactory();
        /**
         * 设置ip
         * port
         * 用户名
         * 密码
         */
        connectionFactory.setHost(IP_ADDRESS);
        connectionFactory.setPort(PORT);
        connectionFactory.setUsername(USER_NAME);
        connectionFactory.setPassword(PASSWORD);
        
        /**
         * 创建连接
         */
        Connection connection = connectionFactory.newConnection();
        
        /**
         * 创建信道
         */
        Channel channel = connection.createChannel();
        
        /**
         * 创建一个type=direct 持久化的 非自动删除的交换器
         */
        
        channel.exchangeDeclare(EXCHANGE_NAME, "direct", true, false, null);

exchangeDeclare方法

exchangeDeclare有很多的方法重载

 Exchange.DeclareOk exchangeDeclare(String exchange, String type) throws IOException;


 Exchange.DeclareOk exchangeDeclare(String exchange, BuiltinExchangeType type) throws IOException;


 Exchange.DeclareOk exchangeDeclare(String exchange, String type, boolean durable) throws IOException;


 Exchange.DeclareOk exchangeDeclare(String exchange, BuiltinExchangeType type, boolean durable) throws IOException;


Exchange.DeclareOk exchangeDeclare(String exchange, String type, boolean durable, boolean autoDelete,
                                       Map arguments) throws IOException;


    Exchange.DeclareOk exchangeDeclare(String exchange, BuiltinExchangeType type, boolean durable, boolean autoDelete,
        Map arguments) throws IOException;


Exchange.DeclareOk exchangeDeclare(String exchange,
                                              String type,
                                              boolean durable,
                                              boolean autoDelete,
                                              boolean internal,
                                              Map arguments) throws IOException;

 Exchange.DeclareOk exchangeDeclare(String exchange,
        BuiltinExchangeType type,
        boolean durable,
        boolean autoDelete,
        boolean internal,
        Map arguments) throws IOException;

exchange: 交换器名称
type : 交换器类型 DIRECT("direct"), FANOUT("fanout"), TOPIC("topic"), HEADERS("headers");
durable: 是否持久化,durable设置为true表示持久化,反之是非持久化,持久化的可以将交换器存盘,在服务器重启的时候不会丢失信息.
autoDelete是否自动删除,设置为TRUE则表是自动删除,自删除的前提是至少有一个队列或者交换器与这交换器绑定,之后所有与这个交换器绑定的队列或者交换器都与此解绑,一般都设置为fase
internal 是否内置,如果设置为true,则表示是内置的交换器,客户端程序无法直接发送消息到这个交换器中,只能通过交换器路由到交换器的方式
arguments:其它一些结构化参数比如:alternate-exchange
BuiltinExchangeType

package com.rabbitmq.client;

/**
 * Enum for built-in exchange types.
 */
public enum BuiltinExchangeType {

    DIRECT("direct"), FANOUT("fanout"), TOPIC("topic"), HEADERS("headers");

    private final String type;

    BuiltinExchangeType(String type) {
        this.type = type;
    }

    public String getType() {
        return type;
    }
}

师出同门 exchangeDeclareNoWait

  void exchangeDeclareNoWait(String exchange,
                               String type,
                               boolean durable,
                               boolean autoDelete,
                               boolean internal,
                               Map arguments) throws IOException;


 void exchangeDeclareNoWait(String exchange,
        BuiltinExchangeType type,
        boolean durable,
        boolean autoDelete,
        boolean internal,
        Map arguments) throws IOException;

实现

  @Override
    public void exchangeDeclareNoWait(String exchange,
                                      String type,
                                      boolean durable,
                                      boolean autoDelete,
                                      boolean internal,
                                      Map arguments) throws IOException {
        transmit(new AMQCommand(new Exchange.Declare.Builder()
                                .exchange(exchange)
                                .type(type)
                                .durable(durable)
                                .autoDelete(autoDelete)
                                .internal(internal)
                                .arguments(arguments)
                                .passive(false)
                                .nowait(true)
                                .build()));
    }

比exchangeDeclare多设置了个nowait参数,
不需要服务器返回,这个方法返回是void,而普通的exchangeDeclare方法返返回值是Exchange.DeclareOk
意思是在客户商端声明一个交换器之后,需要等待服务器返回(服务器会返回Exchange.DeclareOk)
exchangeDeclareNoWait在声明一个交换器后,实际上服务器并没有完成交换器的创建,此时客户端接着使用这个交换器,就会发生异常,不建议使用个这方法

exchangeDeclarePassive

Exchange.DeclareOk exchangeDeclarePassive(String name) throws IOException;

主要用来检测相应的交换器是否存在,如果存在就正常返回,不存就是抛出异常404 channel exception,同是channel也会被关闭

exchangeDelete

Exchange.DeleteOk exchangeDelete(String exchange, boolean ifUnused) throws IOException;

Exchange.DeleteOk exchangeDelete(String exchange) throws IOException;

 void exchangeDeleteNoWait(String exchange, boolean ifUnused) throws IOException;

exchange交换器的名称
ifUnused同来设置是否在交换器没有被使用的情况下删除,true,则只有在此交换器没有被使用的情况下才删除,false,则无论如何这个交换器都要被删除