Java com.fasterxml.jackson.databind.exc.InvalidDefinitionException:找不到类org.hibernate.proxy.pojo.b的序列化程序

我正在使用SpringBootRESTAPI，在尝试从MySQL数据库检索数据时遇到了这个异常。这个数据库是关于总线的，我可以检索所有总线。但不能通过提供

总线id

乘坐一辆总线。当我尝试它时，它显示以下结果

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.hibernate.proxy.pojo.bytebuddy.ByteBuddyInterceptor and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: com.example.bus.model.Bus$HibernateProxy$TkXYYwsN["hibernateLazyInitializer"])
at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1191) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.DatabindContext.reportBadDefinition(DatabindContext.java:404) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:71) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:33) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:722) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1433) ~[jackson-databind-2.10.1.jar:2.10.1]
at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:921) ~[jackson-databind-2.10.1.jar:2.10.1]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:287) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:104) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:295) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:181) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:124) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_202]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_202]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_202]

正如我在上面所说的，我可以通过调用

http://localhost:8080/buses

endpoint

[
{
    "bus_id": 1,
    "bus_root": "udugama",
    "driver_name": "athula"
},
{
    "bus_id": 2,
    "bus_root": "thawalama",
    "driver_name": "sunil"
}
]

当我调用

http://localhost:8080/bus/1

端点，发生上述错误

Bus.java

package com.example.bus.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Bus {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int bus_id;
    private String bus_root;
    private String driver_name;

    public Bus() {
    }

    public int getBus_id() {
        return bus_id;
    }

    public void setBus_id(int bus_id) {
        this.bus_id = bus_id;
    }

    public String getBus_root() {
        return bus_root;
    }

    public void setBus_root(String bus_root) {
        this.bus_root = bus_root;
    }

    public String getDriver_name() {
        return driver_name;
    }

    public void setDriver_name(String driver_name) {
        this.driver_name = driver_name;
    }
}

package com.example.bus.controller;

import com.example.bus.model.Bus;
import com.example.bus.repository.BusRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import javax.persistence.criteria.CriteriaBuilder;
import java.util.List;

@RestController
public class BusController {

    @Autowired
    BusRepository busRepository;

    @GetMapping("/buses")
    public List<Bus> getAllBus(){
        return busRepository.findAll();
    }

    @GetMapping("/bus/{id}")
    public Bus getOneBus(@PathVariable String id){
        int idNumber = Integer.parseInt(id);
        return busRepository.getOne(idNumber);
    }

    @PostMapping("/bus/add")
    public void addBus(@RequestBody Bus bus){
        busRepository.save(bus);
    }

    @DeleteMapping("/bus/delete/{id}")
    public void deleteBus(@PathVariable String id){
        int idNumber = Integer.parseInt(id);
        busRepository.deleteById(idNumber);
    }

    @PutMapping("bus/update/{id}")
    public void updateBus(@PathVariable String id, @RequestBody Bus bus){
        int number = Integer.parseInt(id);
        Bus bus1 = busRepository.getOne(number);
        bus1.setBus_root(bus.getBus_root());
        bus1.setDriver_name(bus.getDriver_name());
        busRepository.save(bus1);
    }
}

BusController.java

package com.example.bus.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Bus {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int bus_id;
    private String bus_root;
    private String driver_name;

    public Bus() {
    }

    public int getBus_id() {
        return bus_id;
    }

    public void setBus_id(int bus_id) {
        this.bus_id = bus_id;
    }

    public String getBus_root() {
        return bus_root;
    }

    public void setBus_root(String bus_root) {
        this.bus_root = bus_root;
    }

    public String getDriver_name() {
        return driver_name;
    }

    public void setDriver_name(String driver_name) {
        this.driver_name = driver_name;
    }
}

package com.example.bus.controller;

import com.example.bus.model.Bus;
import com.example.bus.repository.BusRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

import javax.persistence.criteria.CriteriaBuilder;
import java.util.List;

@RestController
public class BusController {

    @Autowired
    BusRepository busRepository;

    @GetMapping("/buses")
    public List<Bus> getAllBus(){
        return busRepository.findAll();
    }

    @GetMapping("/bus/{id}")
    public Bus getOneBus(@PathVariable String id){
        int idNumber = Integer.parseInt(id);
        return busRepository.getOne(idNumber);
    }

    @PostMapping("/bus/add")
    public void addBus(@RequestBody Bus bus){
        busRepository.save(bus);
    }

    @DeleteMapping("/bus/delete/{id}")
    public void deleteBus(@PathVariable String id){
        int idNumber = Integer.parseInt(id);
        busRepository.deleteById(idNumber);
    }

    @PutMapping("bus/update/{id}")
    public void updateBus(@PathVariable String id, @RequestBody Bus bus){
        int number = Integer.parseInt(id);
        Bus bus1 = busRepository.getOne(number);
        bus1.setBus_root(bus.getBus_root());
        bus1.setDriver_name(bus.getDriver_name());
        busRepository.save(bus1);
    }
}

BusRepository.java文件

spring.datasource.url=jdbc:mysql://localhost:3306/tution?user=root&password=19940306

package com.example.bus.repository;

import com.example.bus.model.Bus;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface BusRepository extends JpaRepository<Bus, Integer> {
}

package com.example.bus.repository；
导入com.example.bus.model.bus；
导入org.springframework.data.jpa.repository.JpaRepository；
导入org.springframework.stereotype.Repository；
@存储库
公共接口总线存储库扩展了JpaRepository{
}

这是MySql表

---

那么我应该怎么做呢？

——用@JsonIgnoreProperties（{“hibernateLazyInitializer”}）注释实体类，并将最终的serialVersionUID添加到类中。@SiddarthSreeni为什么？这是否回答了您的问题？