spring - 用于创建 Kafka Producer 的演示应用程序为 java.lang.InstantiationException : null 引发 "Failed to construct kafka producer"错误

Question

我正在编写一个演示应用程序来创建一个 Kafka Producer。我创建了一个主题并在 Kafka 上运行了一个生产者和消费者，它似乎正在工作。我正在编写一个 spring 应用程序来创建一个生产者。我将名称作为调用的一部分传递。当我转到“http://localhost:8080/kafka/publish/Peter”时，我收到一个白标错误“无法构建 kafka 生产者”。请帮忙。

主要应用是:SpringBootKafkaProducerApplication.java

package com.ranjana.demo.kafka.springbootkafkaproducer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootKafkaProducerApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootKafkaProducerApplication.class, args);
    }
}

型号是:用户.java

package com.ranjana.demo.kafka.springbootkafkaproducer.model;

public class User {
    private String name;
    private String Department;
    private Long Salary;

    public User(String name, String department, Long salary) {
        this.name = name;
        Department = department;
        Salary = salary;
    }

    //Getters and setters

}

Controller 是 UserResource.java

package com.ranjana.demo.kafka.springbootkafkaproducer.resource;

import com.ranjana.demo.kafka.springbootkafkaproducer.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("kafka")
public class UserResource {
    @Autowired
    KafkaTemplate<String, User> kafkaTemplate;
    private static final String TOPIC = "demo_topic";

    @GetMapping("/publish/{name}")
    public String post(@PathVariable("name") final String name){
        kafkaTemplate.send(TOPIC, new User(name, "Technology", 12000L));
        return "Published Successfully";
    }
}

还有这个配置文件:KafkaConfiguration.java

package com.ranjana.demo.kafka.springbootkafkaproducer.config;

import com.ranjana.demo.kafka.springbootkafkaproducer.model.User;
import com.fasterxml.jackson.databind.JsonSerializer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.serialization.StringSerializer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.core.DefaultKafkaProducerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.core.ProducerFactory;

import java.util.HashMap;
import java.util.Map;

@Configuration
public class KafkaConfiguration {
    @Bean
    public ProducerFactory<String, User> producerFactory(){
        Map<String, Object> config = new HashMap<>();

        config.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "127.0.0.1:9092");
        config.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        config.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);

        return new DefaultKafkaProducerFactory<>(config);
    }

    @Bean
    public KafkaTemplate<String, User> kafkaTemplate(){
        return new KafkaTemplate<>(producerFactory());
    }
}

我的 application.properties 有:

server.port=8080

http://localhost:8080/kafka/publish/Peter 上的错误是:

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Fri Aug 09 12:36:10 CDT 2019
There was an unexpected error (type=Internal Server Error, status=500).
Failed to construct kafka producer

控制台也显示:

"/Applications/IntelliJ IDEA.app/Contents/jbr/Contents/Home/bin/java" -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar=56874:/Applications/IntelliJ IDEA.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath /Users/ranjanasinha/ransinha/spring-boot-kafka-producer/target/classes:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-starter-web/2.1.7.RELEASE/spring-boot-starter-web-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-starter/2.1.7.RELEASE/spring-boot-starter-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot/2.1.7.RELEASE/spring-boot-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.1.7.RELEASE/spring-boot-autoconfigure-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.1.7.RELEASE/spring-boot-starter-logging-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar:/Users/ranjanasinha/.m2/repository/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar:/Users/ranjanasinha/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.11.2/log4j-to-slf4j-2.11.2.jar:/Users/ranjanasinha/.m2/repository/org/apache/logging/log4j/log4j-api/2.11.2/log4j-api-2.11.2.jar:/Users/ranjanasinha/.m2/repository/org/slf4j/jul-to-slf4j/1.7.26/jul-to-slf4j-1.7.26.jar:/Users/ranjanasinha/.m2/repository/javax/annotation/javax.annotation-api/1.3.2/javax.annotation-api-1.3.2.jar:/Users/ranjanasinha/.m2/repository/org/yaml/snakeyaml/1.23/snakeyaml-1.23.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-starter-json/2.1.7.RELEASE/spring-boot-starter-json-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.9.9/jackson-databind-2.9.9.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.9.0/jackson-annotations-2.9.0.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.9.9/jackson-core-2.9.9.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jdk8/2.9.9/jackson-datatype-jdk8-2.9.9.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jsr310/2.9.9/jackson-datatype-jsr310-2.9.9.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/jackson/module/jackson-module-parameter-names/2.9.9/jackson-module-parameter-names-2.9.9.jar:/Users/ranjanasinha/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/2.1.7.RELEASE/spring-boot-starter-tomcat-2.1.7.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.22/tomcat-embed-core-9.0.22.jar:/Users/ranjanasinha/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/9.0.22/tomcat-embed-el-9.0.22.jar:/Users/ranjanasinha/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/9.0.22/tomcat-embed-websocket-9.0.22.jar:/Users/ranjanasinha/.m2/repository/org/hibernate/validator/hibernate-validator/6.0.17.Final/hibernate-validator-6.0.17.Final.jar:/Users/ranjanasinha/.m2/repository/javax/validation/validation-api/2.0.1.Final/validation-api-2.0.1.Final.jar:/Users/ranjanasinha/.m2/repository/org/jboss/logging/jboss-logging/3.3.2.Final/jboss-logging-3.3.2.Final.jar:/Users/ranjanasinha/.m2/repository/com/fasterxml/classmate/1.4.0/classmate-1.4.0.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-web/5.1.9.RELEASE/spring-web-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-beans/5.1.9.RELEASE/spring-beans-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-webmvc/5.1.9.RELEASE/spring-webmvc-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-aop/5.1.9.RELEASE/spring-aop-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-expression/5.1.9.RELEASE/spring-expression-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/kafka/spring-kafka/2.2.8.RELEASE/spring-kafka-2.2.8.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-context/5.1.9.RELEASE/spring-context-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-messaging/5.1.9.RELEASE/spring-messaging-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-tx/5.1.9.RELEASE/spring-tx-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/retry/spring-retry/1.2.4.RELEASE/spring-retry-1.2.4.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/apache/kafka/kafka-clients/2.0.1/kafka-clients-2.0.1.jar:/Users/ranjanasinha/.m2/repository/org/lz4/lz4-java/1.4.1/lz4-java-1.4.1.jar:/Users/ranjanasinha/.m2/repository/org/xerial/snappy/snappy-java/1.1.7.1/snappy-java-1.1.7.1.jar:/Users/ranjanasinha/.m2/repository/org/slf4j/slf4j-api/1.7.26/slf4j-api-1.7.26.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-core/5.1.9.RELEASE/spring-core-5.1.9.RELEASE.jar:/Users/ranjanasinha/.m2/repository/org/springframework/spring-jcl/5.1.9.RELEASE/spring-jcl-5.1.9.RELEASE.jar com.ranjana.demo.kafka.springbootkafkaproducer.SpringBootKafkaProducerApplication

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.1.7.RELEASE)

2019-08-09 12:50:39.250  INFO 14006 --- [           main] d.k.s.SpringBootKafkaProducerApplication : Starting SpringBootKafkaProducerApplication on Egens-MacBook-Pro.local with PID 14006 (/Users/ranjanasinha/ransinha/spring-boot-kafka-producer/target/classes started by ranjanasinha in /Users/ranjanasinha/ransinha/spring-boot-kafka-producer)
2019-08-09 12:50:39.252  INFO 14006 --- [           main] d.k.s.SpringBootKafkaProducerApplication : No active profile set, falling back to default profiles: default
2019-08-09 12:50:39.776  INFO 14006 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.kafka.annotation.KafkaBootstrapConfiguration' of type [org.springframework.kafka.annotation.KafkaBootstrapConfiguration$$EnhancerBySpringCGLIB$$62e8d338] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2019-08-09 12:50:39.964  INFO 14006 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2019-08-09 12:50:39.985  INFO 14006 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2019-08-09 12:50:39.985  INFO 14006 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.22]
2019-08-09 12:50:40.044  INFO 14006 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2019-08-09 12:50:40.044  INFO 14006 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 755 ms
2019-08-09 12:50:40.235  INFO 14006 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2019-08-09 12:50:40.410  INFO 14006 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2019-08-09 12:50:40.415  INFO 14006 --- [           main] d.k.s.SpringBootKafkaProducerApplication : Started SpringBootKafkaProducerApplication in 1.383 seconds (JVM running for 6.925)
2019-08-09 12:50:50.531  INFO 14006 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring DispatcherServlet 'dispatcherServlet'
2019-08-09 12:50:50.531  INFO 14006 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2019-08-09 12:50:50.536  INFO 14006 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed initialization in 5 ms
2019-08-09 12:50:50.565  INFO 14006 --- [nio-8080-exec-1] o.a.k.clients.producer.ProducerConfig    : ProducerConfig values: 
    acks = 1
    batch.size = 16384
    bootstrap.servers = [127.0.0.1:9092]
    buffer.memory = 33554432
    client.id = 
    compression.type = none
    connections.max.idle.ms = 540000
    enable.idempotence = false
    interceptor.classes = []
    key.serializer = class org.apache.kafka.common.serialization.StringSerializer
    linger.ms = 0
    max.block.ms = 60000
    max.in.flight.requests.per.connection = 5
    max.request.size = 1048576
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
    receive.buffer.bytes = 32768
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    retries = 0
    retry.backoff.ms = 100
    sasl.client.callback.handler.class = null
    sasl.jaas.config = null
    sasl.kerberos.kinit.cmd = /usr/bin/kinit
    sasl.kerberos.min.time.before.relogin = 60000
    sasl.kerberos.service.name = null
    sasl.kerberos.ticket.renew.jitter = 0.05
    sasl.kerberos.ticket.renew.window.factor = 0.8
    sasl.login.callback.handler.class = null
    sasl.login.class = null
    sasl.login.refresh.buffer.seconds = 300
    sasl.login.refresh.min.period.seconds = 60
    sasl.login.refresh.window.factor = 0.8
    sasl.login.refresh.window.jitter = 0.05
    sasl.mechanism = GSSAPI
    security.protocol = PLAINTEXT
    send.buffer.bytes = 131072
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
    ssl.endpoint.identification.algorithm = https
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLS
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    transaction.timeout.ms = 60000
    transactional.id = null
    value.serializer = class com.fasterxml.jackson.databind.JsonSerializer

2019-08-09 12:50:50.572  INFO 14006 --- [nio-8080-exec-1] o.a.k.clients.producer.KafkaProducer     : [Producer clientId=producer-1] Closing the Kafka producer with timeoutMillis = 0 ms.
2019-08-09 12:50:50.581 ERROR 14006 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.kafka.common.KafkaException: Failed to construct kafka producer] with root cause

java.lang.InstantiationException: null
    at java.base/jdk.internal.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48) ~[na:na]
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
    at org.apache.kafka.common.utils.Utils.newInstance(Utils.java:306) ~[kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.common.config.AbstractConfig.getConfiguredInstance(AbstractConfig.java:302) ~[kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:370) ~[kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:289) ~[kafka-clients-2.0.1.jar:na]
    at org.springframework.kafka.core.DefaultKafkaProducerFactory.createKafkaProducer(DefaultKafkaProducerFactory.java:318) ~[spring-kafka-2.2.8.RELEASE.jar:2.2.8.RELEASE]
    at org.springframework.kafka.core.DefaultKafkaProducerFactory.createProducer(DefaultKafkaProducerFactory.java:305) ~[spring-kafka-2.2.8.RELEASE.jar:2.2.8.RELEASE]
    at org.springframework.kafka.core.KafkaTemplate.getTheProducer(KafkaTemplate.java:448) ~[spring-kafka-2.2.8.RELEASE.jar:2.2.8.RELEASE]
    at org.springframework.kafka.core.KafkaTemplate.doSend(KafkaTemplate.java:378) ~[spring-kafka-2.2.8.RELEASE.jar:2.2.8.RELEASE]
    at org.springframework.kafka.core.KafkaTemplate.send(KafkaTemplate.java:193) ~[spring-kafka-2.2.8.RELEASE.jar:2.2.8.RELEASE]
    at com.ranjana.demo.kafka.springbootkafkaproducer.resource.UserResource.post(UserResource.java:32) ~[classes/: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:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.22.jar:9.0.22]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

而 pom.xml 是:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.egen.demo.kafka</groupId>
    <artifactId>spring-boot-kafka-producer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-kafka-producer</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.kafka</groupId>
            <artifactId>spring-kafka-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Answer 1

来自您的控制台日志value.serializer = class com.fasterxml.jackson.databind.JsonSerializer

使用 org.springframework.kafka.support.serializer.JsonSerializer 代替 jackson 的序列化器

尝试构造与 VALUE_SERIALIZER_CLASS_CONFIG 属性对应的类的实例时发生异常。

VALUE_SERIALIZER_CLASS_CONFIG 的值必须是实现了 org.apache.kafka.common.serialization.Serializer 接口(interface)的类。

jackson.databind.JsonSerializer 不满足此条件并导致 InstantiationException。所以使用实现上述 Serializer 接口(interface)的 org.springframework.kafka.support.serializer.JsonSerializer。