无法发送UDP消息的响应

Question

我正在尝试通过以下方式发送消息：

netcat -u localhost 11111abcd

我只需要让客户得到答案即可：OK它会收到消息并尝试以OK进行回答。 但这无限地将其写入应用程序日志：

消息：GenericMessage [有效载荷=字节[2]，标头= {ip_packetAddress = 127.0.0.1 / 127.0.0.1：49489，ip_address = 127.0.0.1，id = 8db6aa3b-b56b-6dce-9554-c7b0ce050142，ip_port = 49489，ip_hostname = 127.0.0.1，timestamp = 1494442285767}]

消息有效负载：确定

配置：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int="http://www.springframework.org/schema/integration"
    xmlns:int-ip="http://www.springframework.org/schema/integration/ip"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd
        http://www.springframework.org/schema/integration/ip http://www.springframework.org/schema/integration/ip/spring-integration-ip.xsd">

  <int:channel id="sendUdp"/>

  <int-ip:udp-outbound-channel-adapter id="udpOut" host="localhost" port="11111"
                                   multicast="false" check-length="false"
                                   channel="sendUdp" />

  <int-ip:udp-inbound-channel-adapter id="udpIn" port="11111" receive-buffer-size="500"
                                  multicast="false" check-length="false"
                                  channel="receiveUdp"/>

  <int:service-activator id="updHandler" input-channel="receiveUdp" output-channel="sendUdp" ref="listener"/>

</beans>

@ServiceActivator
public String handle(Message<?> message) {
    System.out.println("*** Message: " + message);
    String command = new String((byte[]) message.getPayload());
    System.out.println("*** Message Payload: "
            + command);
    String response = "OK";

    return response;
}

Answer 1

您的出站适配器正在将消息发送到入站适配器。 如果要回复数据包，则需要配置套接字和目标表达式。 请参阅文档 。

<int-ip:udp-inbound-channel-adapter id="inbound" port="11111" channel="in" />

<int:channel id="in" />

<int:transformer expression="new String(payload).toUpperCase()"
                       input-channel="in" output-channel="out"/>

<int:channel id="out" />

<int-ip:udp-outbound-channel-adapter id="outbound"
                        socket-expression="@inbound.socket"
                        destination-expression="headers['ip_packetAddress']"
                        channel="out" />