Spring Boot RabbitMQ接收机Jackson反序列化为POJO
Spring Boot RabbitMQ接收机Jackson反序列化为POJO
提问于 2017-08-22 21:25:18
我有一个spring引导项目，在这个项目中，我试图与一个rabbitmq服务器集成，这样我就可以将消息发布到/从队列中读取。
以下是我的rabbitmq配置(编辑后只显示相关细节)：
@Configuration
@ConfigurationProperties(prefix="rabbit")
public class RabbitConfig {
private String queue;
@Bean
Queue queue() {
return new Queue(queue, durable);
}
@Bean
public MessageConverter jsonMessageConverter(){
return new Jackson2JsonMessageConverter();
}
@Bean
SimpleMessageListenerContainer container(ConnectionFactory connectionFactory, Queue queue,
MessageListenerAdapter listenerAdapter, MessageConverter messageConverter) {
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(connectionFactory);
container.setQueues(queue);
container.setMessageListener(listenerAdapter);
container.setMessageConverter(messageConverter);
return container;
}
@Bean
MessageListenerAdapter listenerAdapter(Receiver receiver) {
return new MessageListenerAdapter(receiver);
}
public void setQueue(String queue) {
this.queue = queue;
}
}这是我的接受者课程：
public interface Receiver {
void handleMessage(FooA message);
}
@Component
public class RabbitReceiver implements Receiver {
@Override
public void handleMessage(FooA message) {
System.out.println(message);
}
}我的波乔：
public class FooA {}
private double num;
private Map<String, String> map = new HashMap();
public FooA() {
}
public FooA(double num, Map<String, String> map) {
this.num = num;
this.map = map;
}
public int getnum() {
return num;
}
public Map<String, String> getMap() {
return map;
}
}我能够成功地将FooA消息对象发布到队列中。下面是队列中的样子：
[
{
"payload_bytes": 41,
"redelivered": false,
"exchange": "amq.fanout",
"routing_key": "",
"message_count": 0,
"properties": {
"priority": 0,
"delivery_mode": 2,
"headers": {
"__TypeId__": "com.test.FooA"
},
"content_encoding": "UTF-8",
"content_type": "application/json"
},
"payload": "{\"num\":1.2,\"map\":{}}",
"payload_encoding": "string"
}
]但是，当我试图从队列中读取时，我会得到以下错误：
org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Failed to invoke target method 'handleMessage' with argument type = [class [B], value = [{[B@75a7bfc9}]
at org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter.invokeListenerMethod(MessageListenerAdapter.java:408) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter.onMessage(MessageListenerAdapter.java:298) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:822) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:745) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$001(SimpleMessageListenerContainer.java:97) [spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$1.invokeListener(SimpleMessageListenerContainer.java:189) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.invokeListener(SimpleMessageListenerContainer.java:1276) [spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:726) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:1219) [spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:1189) [spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$1500(SimpleMessageListenerContainer.java:97) [spring-rabbit-1.7.3.RELEASE.jar:na]
at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1421) [spring-rabbit-1.7.3.RELEASE.jar:na]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121]
Caused by: java.lang.NoSuchMethodException: com.test.RabbitReceiver.handleMessage([B)
at java.lang.Class.getMethod(Class.java:1786) ~[na:1.8.0_121]
at org.springframework.util.MethodInvoker.prepare(MethodInvoker.java:174) ~[spring-core-4.3.9.RELEASE.jar:4.3.9.RELEASE]
at org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter.invokeListenerMethod(MessageListenerAdapter.java:386) ~[spring-rabbit-1.7.3.RELEASE.jar:na]
... 12 common frames omitted我做错了什么？
编辑1：我将方法更改为：
@Override
public void handleMessage(byte[] message) {
System.out.println(message);
}效果很好，但完全不能用。它就是这样出现的：
如何将它映射到我的pojo FooA
回答 5
Stack Overflow用户
回答已采纳
发布于 2017-08-24 23:29:48
我刚刚让实现Serializable接口的类删除了JsonMessageConverter。Json和Serializable是相互冲突的，所以它不起作用。
Stack Overflow用户
发布于 2017-11-22 21:11:25
将字节数组转换为字符串，并使用jackson (ObjectMapper)映射到pojo。你的地图上有配置。
this.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
this.configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false);
this.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
this.registerModule(new JavaTimeModule())Stack Overflow用户
发布于 2017-08-22 21:47:24
看起来，消息是以字符串形式发布的，而不是JSON。这就是你所看到的
"payload_encoding": "string"Spring可以自动将此字符串转换为byte[]，如屏幕截图所示。
还需要在RabbitTemplate上设置消息转换器，如下所示：
@Bean
public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory,MessageConverter rabbitJsonMessageConverter) {
RabbitTemplate template = new RabbitTemplate(connectionFactory);
template.setMessageConverter(rabbitJsonMessageConverter);
return template;
}这将正确地将消息发布为JSON。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/45827213
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