1.SQSConfig：我正在尝试使用Spring Boot框架使用SQS侦听器从Amazon SQS队列读取数据，其中我编写了以下代码。但是，对于simpleMessageListenerContainer，存在一个问题。谁能解释我该如何为该对象而不是常规的Java对象创建bin。
我的主要目的是读取SQS队列并获取队列中可用的消息。如果有人举任何例子，将会很有帮助。
package com.wxyz.imaging.configuration;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.auth.DefaultAWSCredentialsProviderChain;
import com.amazonaws.services.sqs.AmazonSQSAsync;
import com.amazonaws.services.sqs.AmazonSQSAsyncClientBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.aws.messaging.core.QueueMessagingTemplate;
import org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
@Configuration
public class SQSConfiguration {
@Bean
AWSCredentialsProvider credentialsProvider() {
return new DefaultAWSCredentialsProviderChain();
}
@Autowired
protected AWSCredentialsProvider credProvider;
@Bean
@Primary
public AmazonSQSAsync amazonSQSAsync() {
return AmazonSQSAsyncClientBuilder.standard().
withCredentials(credProvider).
build();
}
@Bean
public SimpleMessageListenerContainer simpleMessageListenerContainer(AmazonSQSAsync amazonSQSAsync) {
SimpleMessageListenerContainer simpleMessageListenerContainer = new SimpleMessageListenerContainer();
simpleMessageListenerContainer.setAmazonSqs(amazonSQSAsync);
simpleMessageListenerContainer.setMaxNumberOfMessages(10);
return simpleMessageListenerContainer;
}
@Bean
public QueueMessagingTemplate messagingTemplate(@Autowired AmazonSQSAsync amazonSQSAsync) {
return new QueueMessagingTemplate(amazonSQSAsync);
}
} 2.SQSListener
package com.wxyz.imaging.Listener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.aws.messaging.listener.SqsMessageDeletionPolicy;
import org.springframework.cloud.aws.messaging.listener.annotation.SqsListener;
import org.springframework.messaging.handler.annotation.Headers;
import org.springframework.messaging.handler.annotation.Payload;
import java.util.Map;
public class SQSListener {
private static final Logger logger = LoggerFactory.getLogger(SQSListener.class);
@SqsListener(value = "${imaging-scanner-queue}", deletionPolicy = SqsMessageDeletionPolicy.ALWAYS)
public void receive(@Headers Map<String, String> header, @Payload String message) {
try {
logger.info("Message payload is: " + message);
logger.info("Header from SQS is: " + header);
} catch (Exception e) {
System.out.print(e);
}
}
}
3.Application.properties
sqs.region= us-west-2
sqs.queueName= imaging-scanner-queue
Error
2018-07-20 15:44:05.348 WARN 48026 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'simpleMessageListenerContainer' defined in class path resource [com/wxyz/imaging/configuration/SQSConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: messageHandler must not be null
2018-07-20 15:44:05.352 INFO 48026 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2018-07-20 15:44:05.366 INFO 48026 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2018-07-20 15:44:05.372 ERROR 48026 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'simpleMessageListenerContainer' defined in class path resource [com/wxyz/imaging/configuration/SQSConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: messageHandler must not be null
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1708) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:581) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:760) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
at com.wxyz.imaging.Application.main(Application.java:11) [classes/:na]
Caused by: java.lang.IllegalStateException: messageHandler must not be null
at org.springframework.util.Assert.state(Assert.java:73) ~[spring-core-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.cloud.aws.messaging.listener.AbstractMessageListenerContainer.validateConfiguration(AbstractMessageListenerContainer.java:255) ~[spring-cloud-aws-messaging-1.1.0.RELEASE.jar:1.1.0.RELEASE]
at org.springframework.cloud.aws.messaging.listener.AbstractMessageListenerContainer.afterPropertiesSet(AbstractMessageListenerContainer.java:249) ~[spring-cloud-aws-messaging-1.1.0.RELEASE.jar:1.1.0.RELEASE]
at org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer.a fterPropertiesSet(SimpleMessageListenerContainer.java:44) ~[spring-cloud-aws-messaging-1.1.0.RELEASE.jar:1.1.0.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1767) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1704) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
... 16 common frames omitted
以退出代码1完成的过程