使用jackson json、spring和hibernate时出现java.lang.StackOverflowError错误

Question

使用jackson json、spring和hibernate时出现java.lang.StackOverflowError错误

10

我有两个双向的一对多关系，但是我遇到了stackoverflow异常，不知道出现问题的具体原因和位置在哪里？每个事件包含一个位置和多个会话。

@Entity
@Table(name = "session")
public class Session {
    @Id
    @Column(name = "idsession")
    int idsession;


 @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "idevent")
    Event event ;

.
.
.
}

event.java

@Entity
    @Table(name="event")
    public class Event {

        @Column(name = "idevent")
        @Id
        private int idevent;

      @OneToMany(cascade = CascadeType.ALL)
        @JoinColumn(name = "idevent")
        private List<Session> sessions = new ArrayList<Session>();
               }

location.java

@Entity
@Table(name="location")
public class Location {

    @Id
    @Column(name = "idlocation" )

    @OneToOne
    @JoinColumn(name = "idevent")
    private Event event;
}

控制器

@RequestMapping(value="/events", method=RequestMethod.GET)
public @ResponseBody
List<Event> events() {


    return  eventService.getAllEvents() ;
}

编辑：

EventDaoImpl that eventService uses it. 
    @Repository
    @Transactional(readOnly = true)
    public class EventDaoImpl implements  EventDao {

        @Autowired
        private SessionFactory sessionFactory;

        @Override
        public List<Event> getAllEvents() {
            Session session = sessionFactory.openSession();
            String hql = "FROM Event";
            Query query = session.createQuery(hql);
            List<Event> eventList = query.list();
            System.err.print("lengthhh" + eventList.size());
            return eventList;
        }
}

异常跟踪：

 Handling of [org.springframework.http.converter.HttpMessageNotWritableException] resulted in Exception
java.lang.IllegalStateException
    at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:501)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.sendServerError(DefaultHandlerExceptionResolver.java:313)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleHttpMessageNotWritable(DefaultHandlerExceptionResolver.java:370)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.doResolveException(DefaultHandlerExceptionResolver.java:140)
    at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:138)
    at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1167)
    at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1004)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
    at java.lang.Thread.run(Thread.java:745)
]]

[2016-10-11T22:40:22.158+0330] [glassfish 4.1] [WARNING] [] [org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver] [tid: _ThreadID=27 _ThreadName=http-listener-1(1)] [timeMillis: 1476213022158] [levelValue: 900] [[
  Handling of [org.springframework.http.converter.HttpMessageNotWritableException] resulted in Exception
java.lang.IllegalStateException
    at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:501)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.sendServerError(DefaultHandlerExceptionResolver.java:313)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleHttpMessageNotWritable(DefaultHandlerExceptionResolver.java:370)
    at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.doResolveException(DefaultHandlerExceptionResolver.java:140)
    at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:138)
    at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1167)
    at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1004)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
    at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:415)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:282)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:201)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:175)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:561)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:565)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:545)
    at java.lang.Thread.run(Thread.java:745)
]]

[2016-10-11T22:40:22.162+0330] [glassfish 4.1] [WARNING] [] [javax.enterprise.web] [tid: _ThreadID=27 _ThreadName=http-listener-1(1)] [timeMillis: 1476213022162] [levelValue: 900] [[
  StandardWrapperValve[mvc-dispatcher]: Servlet.service() for servlet mvc-dispatcher threw exception
java.lang.StackOverflowError
    at java.lang.Exception.<init>(Exception.java:66)
    at java.io.IOException.<init>(IOException.java:58)
    at com.fasterxml.jackson.core.JsonProcessingException.<init>(JsonProcessingException.java:27)
    at com.fasterxml.jackson.core.JsonProcessingException.<init>(JsonProcessingException.java:46)
    at com.fasterxml.jackson.databind.JsonMappingException.<init>(JsonMappingException.java:149)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:658)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:541)
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:644)

问题解决：

通过为具有双向关系的两个字段添加“JsonIgnore”来解决问题....@onetoOne和@OneToMany。

- faraa

你能发布完整的错误日志和eventService类吗？ - Sundararaj Govindasamy

@AliDehghani 我在事件类中添加了getSessions()方法...但我仍然遇到异常...我真的使用它吗？;) - faraa

1

将堆栈跟踪添加到您的问题中可能会有所帮助。 - Nicolas Filotto

@SundararajGovindasamy我添加了。 - faraa

@SundararajGovindasamy 不，我已经添加了所有相关的代码...我没有。 - faraa

显示剩余2条评论

2个回答

5

你的错误（你的堆栈跟踪证实了这一点）是由于 jackson序列化试图解决一个引用循环 在你的Event和Session类之间。大多数序列化框架需要一些提示才能解决这些循环引用，否则它们最终会:

序列化事件"A"
序列化事件"A"的所有会话
序列化第一个会话的父级，即事件"A"
再次序列化事件"A" ...

你应该通过指示序列化器忽略父对象来打破这个循环，你可以使用:

@JsonIgnore

以下是一篇关于同样主题的stackoverflow问题：
Json 和 Java - 循环引用

- Gergely Bacso

非常感谢您...您的意思是我应该在事件类中的getSessions()方法之前添加@JsonIgnore吗？ - faraa

根据Jackson版本的不同，您可能需要尝试调整注释的位置。可以在字段上或getter上使用。如果不起作用，请阅读我包含的链接。 - Gergely Bacso

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可以查看英文原文，
原文链接

- hetec · Accepted Answer

我认为在json序列化过程中存在循环引用。当您开始将包含事件字段的会话对象序列化为json时，Jackson也会尝试将被引用的事件对象进行序列化。问题在于事件对象本身引用会话对象。因此，如果jackson到达事件对象中的会话字段，它会再次尝试对会话对象进行序列化。这将导致无限循环并导致堆栈溢出错误。

因此，您需要使用@JsonIgnore注解或类似的方法排除其中一个字段（会话或事件）不参与序列化过程。哪个类中的哪个字段应该被排除取决于您的应用程序需求，因为它会影响生成的json结构。