如何通过Web API调用从Kafka使用者获取特定消息？

Question

I'm writing a web application where the user can send a request for messages received in a Kafka consumer. I tried to do this by putting a Map object in the session, and then upon receiving the message put the message in the Map object. Meanwhile in the request-dealing method use a loop to check if the Map is filled with the message. Now the problem is that I can't manage to obtain the session object in the consumer object so it doesn't work out this way. And also if there any other way to do this please let me know.

Here's the request-dealing method:

@Override
public Map<String, Object> getKeyValueMap(String pileCode) {
    String uniqueId = "GetConfiguration" + new Date().getTime();
    session.setAttribute("uniqueId", uniqueId);

    GetConfigurationReq obj = new GetConfigurationReq();
    obj.setKey("getConfiguration");
    GetConfigurationReq.Data data = new GetConfigurationReq.Data();
    data.setConnector(pileCode);
    data.setUniqueId(uniqueId);
    List<KeyValue> keyValue = new ArrayList<>();
    for (int i = 0; i < KeyConstant.PARAMS.length; i++) {
        KeyValue temp = new KeyValue();
        temp.setKey(KeyConstant.PARAMS[i]);
        temp.setValue("0");
        keyValue.add(temp);
    }
    data.setKeyValue(keyValue);
    obj.setData(data);
    String msg = new Gson().toJson(obj);
    ConnectorChargingOperationProducer producer = new ConnectorChargingOperationProducer();
    producer.responseOperation(KeyConstant.KAFKA_PUB, "getConfiguration", msg);

    Map params = (Map) session.getAttribute("params");
    try {
        int n = 0;
        while (params.size() == 0) {
            Thread.sleep(1000);
            n++;
            if (n == 20) {
                System.out.printf("After %s seconds waiting timeout%n", n);
                break;
            }
        }
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return params;
}

The consumer class:

public class ConnectorChargingOperationConsumer implements MessageListener<String,String> {
private static Logger logger = LogManager.getLogger(ConnectorChargingOperationConsumer.class);

@Autowired
HttpSession session;

@Override
public void onMessage(ConsumerRecord<String, String> consumerRecord) {
    String message = consumerRecord.value();
    System.out.println("xxx: " + message);
    logger.info("yyy: " + message);
    Gson gson = new Gson();
    JsonObject respObj = gson.fromJson(message, JsonObject.class);
    JsonElement uniqueId = respObj.get("uniqueId");
    if (uniqueId != null) {
        String uniqueId2 = (String) session.getAttribute("uniqueId");
        if (uniqueId.getAsString().equals(uniqueId2)) {
            GetConfigurationResp resp = gson.fromJson(respObj, GetConfigurationResp.class);
            List<KeyValue> keyValue = resp.getKeyValue();
            Map params = (Map) session.getAttribute("params");
            for (int i = 0; i < keyValue.size(); i++) {
                KeyValue temp = keyValue.get(i);
                params.put(temp.getKey(), temp.getValue());
            }
        }
    }
}
}

Exceptions thrown when called:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'messageListernerConsumerService': Unsatisfied dependency expressed through field 'session': No qualifying bean of type [javax.servlet.http.HttpSession] found for dependency [javax.servlet.http.HttpSession]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.servlet.http.HttpSession] found for dependency [javax.servlet.http.HttpSession]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.yunshan.openCharge.kafka.ConnectorChargingOperationProducer.responseOperation(ConnectorChargingOperationProducer.java:30)
at com.yunshan.openCharge.service.impl.PileServiceImpl.getKeyValueMap(PileServiceImpl.java:260)
at com.yunshan.openCharge.controller.PileController.getParameters(PileController.java:158)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.servlet.http.HttpSession] found for dependency [javax.servlet.http.HttpSession]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1406)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1057)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566)
... 59 more

Answer 1

I solved the problem eventually by using a static Map field in the consumer class instead of trying to put it in the session, namely:

replace:

@Autowired
HttpSession session;

with

public static final Map<String, Object> PARAMS = new HashMap<>();