英文:
class java.lang.String cannot be cast to class java.util.List (java.lang.String and java.util.List are in module java.base of loader 'bootstrap')
问题
Trying to use ReplyingKafkaTemplate to return the response from the service, but keep getting an error `java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.List (java.lang.String and java.util.List are in module java.base of loader 'bootstrap')`
# Listener
@KafkaListener(id = ProductTopicConstants.GET_PRODUCTS, topics = ProductTopicConstants.GET_PRODUCTS, splitIterables = false)
@SendTo
public List<Product> GetProducts(@Payload(required = false) String payload) {
List<Product> products = _productRepository.findAll();
return new ArrayList<>(products);
}
# KafkaConfiguration
@Configuration
public class KafkaConfiguration {
@Bean
public ReplyingKafkaTemplate<String, String, List<Product>> replyer(
ProducerFactory<String, String> pf,
ConcurrentKafkaListenerContainerFactory<String, List<Product>> containerFactory
) {
containerFactory.setReplyTemplate(kafkaTemplate(pf));
ConcurrentMessageListenerContainer<String, List<Product>> container = replyContainer(containerFactory);
ReplyingKafkaTemplate<String, String, List<Product>> replyer = new ReplyingKafkaTemplate<>(pf, container);
return replyer;
}
@Bean
public ConcurrentMessageListenerContainer<String, List<Product>> replyContainer(
ConcurrentKafkaListenerContainerFactory<String, List<Product>> containerFactory
) {
ConcurrentMessageListenerContainer<String, List<Product>> container =
containerFactory.createContainer(ProductTopicConstants.GET_PRODUCTS_CONTAINER);
container.getContainerProperties().setGroupId(ProductTopicConstants.GET_PRODUCTS_CONTAINER);
container.setBatchErrorHandler(new BatchLoggingErrorHandler());
return container;
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate(ProducerFactory<String, String> pf) {
return new KafkaTemplate<>(pf);
}
@Bean
public NewTopic GetProducts() {
return TopicBuilder.name(ProductTopicConstants.GET_PRODUCTS).partitions(1).replicas(1).build();
}
@Bean
public NewTopic GetProductsContainer() {
return TopicBuilder.name(ProductTopicConstants.GET_PRODUCTS_CONTAINER).partitions(1).replicas(1).build();
}
}
# service
@Service
public class ProductProducer implements IProductProducer {
private final ReplyingKafkaTemplate<String, String, List<Product>> _replyTemplate;
private static final Logger LOG = LoggerFactory.getLogger(ProductProducer.class);
public ProductProducer(ReplyingKafkaTemplate<String, String, List<Product>> replyTemplate) {
this._replyTemplate = replyTemplate;
}
@Override
public List<ProductViewModel> GetProducts() throws InterruptedException, ExecutionException, TimeoutException {
RequestReplyFuture<String, String, List<Product>> future =
this._replyTemplate.sendAndReceive(new ProducerRecord<>(ProductTopicConstants.GET_PRODUCTS, 0, null, null));
LOG.info(future.getSendFuture().get(10, TimeUnit.SECONDS).getRecordMetadata().toString());
List<Product> value = future.get(10, TimeUnit.SECONDS).value(); --> Getting an error over here
return List.of(new ProductViewModel("", "", 0, ""));
}
}
# Error
Getting an error over here `List<Product> value = future.get(10, TimeUnit.SECONDS).value();`
java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.List (java.lang.String and java.util.List are in module java.base of loader 'bootstrap')
at fete.bird.fetebirdproduct.service.producer.ProductProducer.GetProducts(ProductProducer.java:40) ~[main/:na]
...
(代码部分已经翻译完毕，以下内容不再包含翻译。)
英文:
Trying to use ReplyingKafkaTemplate to return the response from the service, but keep getting an error java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.List (java.lang.String and java.util.List are in module java.base of loader 'bootstrap')
Listener
@KafkaListener(id = ProductTopicConstants.GET_PRODUCTS, topics = ProductTopicConstants.GET_PRODUCTS,splitIterables = false)
@SendTo
public List<Product> GetProducts(@Payload(required = false) String payload) {
List<Product> products = _productRepository.findAll();
return new ArrayList<>(products);
}
KafkaConfiguration
@Configuration
public class KafkaConfiguration {
@Bean
public ReplyingKafkaTemplate<String, String, List<Product>> replyer(ProducerFactory<String, String> pf,
ConcurrentKafkaListenerContainerFactory<String, List<Product>> containerFactory) {
containerFactory.setReplyTemplate(kafkaTemplate(pf));
ConcurrentMessageListenerContainer<String, List<Product>> container = replyContainer(containerFactory);
ReplyingKafkaTemplate<String, String, List<Product>> replyer = new ReplyingKafkaTemplate<>(pf, container);
return replyer;
}
@Bean
public ConcurrentMessageListenerContainer<String, List<Product>> replyContainer(
ConcurrentKafkaListenerContainerFactory<String, List<Product>> containerFactory) {
ConcurrentMessageListenerContainer<String, List<Product>> container =
containerFactory.createContainer(ProductTopicConstants.GET_PRODUCTS_CONTAINER);
container.getContainerProperties().setGroupId(ProductTopicConstants.GET_PRODUCTS_CONTAINER);
container.setBatchErrorHandler(new BatchLoggingErrorHandler());
return container;
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate(ProducerFactory<String, String> pf) {
return new KafkaTemplate<>(pf);
}
@Bean
public NewTopic GetProducts() {
return TopicBuilder.name(ProductTopicConstants.GET_PRODUCTS).partitions(1).replicas(1).build();
}
@Bean
public NewTopic GetProductsContainer() {
return TopicBuilder.name(ProductTopicConstants.GET_PRODUCTS_CONTAINER).partitions(1).replicas(1).build();
}
}
service
@Service
public class ProductProducer implements IProductProducer{
private final ReplyingKafkaTemplate<String, String, List<Product>> _replyTemplate;
private static final Logger LOG = LoggerFactory.getLogger(ProductProducer.class);
public ProductProducer(ReplyingKafkaTemplate<String, String, List<Product>> replyTemplate) {
this._replyTemplate = replyTemplate;
}
@Override
public List<ProductViewModel> GetProducts() throws InterruptedException, ExecutionException, TimeoutException {
RequestReplyFuture<String, String, List<Product>> future =
this._replyTemplate.sendAndReceive(new ProducerRecord<>(ProductTopicConstants.GET_PRODUCTS, 0, null, null));
LOG.info(future.getSendFuture().get(10, TimeUnit.SECONDS).getRecordMetadata().toString());
List<Product> value = future.get(10, TimeUnit.SECONDS).value(); --> Getting an error over here
return List.of(new ProductViewModel("","",0,""));
}
}
Error
Getting an error over here List<Product> value = future.get(10, TimeUnit.SECONDS).value();
java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.List (java.lang.String and java.util.List are in module java.base of loader 'bootstrap')
at fete.bird.fetebirdproduct.service.producer.ProductProducer.GetProducts(ProductProducer.java:40) ~[main/:na]
at fete.bird.fetebirdproduct.api.v1.controller.ProductController.Products(ProductController.java:43) ~[main/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:93) ~[spring-boot-actuator-2.3.1.RELEASE.jar:2.3.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.7.RELEASE.jar:5.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.36.jar:9.0.36]
at java.base/java.lang.Thread.run(Thread.java:832) ~[na:na]
Configuration
spring:
profiles:
active: dev
kafka:
bootstrapAddress: localhost:9092
producer:
key-serializer: org.springframework.kafka.support.serializer.JsonSerializer
value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
consumer:
key-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
auto-offset-reset: earliest
properties:
spring:
json:
trusted:
packages: *
答案1
得分: 1
我在包名前缺少 '*'
spring:
profiles:
active: dev
kafka:
bootstrapAddress: localhost:9092
producer:
key-serializer: org.springframework.kafka.support.serializer.JsonSerializer
value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
consumer:
key-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
auto-offset-reset: earliest
properties:
spring:
json:
trusted:
packages: '*'
英文:
I was missing '*' at the package
spring:
profiles:
active: dev
kafka:
bootstrapAddress: localhost:9092
producer:
key-serializer: org.springframework.kafka.support.serializer.JsonSerializer
value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
consumer:
key-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
auto-offset-reset: earliest
properties:
spring:
json:
trusted:
packages: '*'
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论