春季休息 - 異常生產Json數據

我有一個值對象，我想通過JSON休息調用公開。我在我的項目中有許多其他的休息電話，工作很好，但這1沒有出於某種原因。當我嘗試並返回該對象回來 - 我得到的是我不知道的異常如何解決春季休息 - 異常生產Json數據

值對象的代碼如下（負的存取方法）

package com.test.domain.dao; 

    import java.io.Serializable; 
    import java.util.HashSet; 
    import java.util.Set; 

    import javax.persistence.Column; 
    import javax.persistence.Entity; 
    import javax.persistence.FetchType; 
    import javax.persistence.GeneratedValue; 
    import javax.persistence.GenerationType; 
    import javax.persistence.Id; 
    import javax.persistence.OneToMany; 
    import javax.persistence.Table; 

    import org.hibernate.annotations.Cascade; 
    import org.hibernate.annotations.CascadeType; 

    import com.fasterxml.jackson.annotation.JsonIgnore; 

    @Entity 
    @Table(name = "company") 
    public class CompanyVO extends BaseDAOVO implements Serializable{ 


     /** 
     * 
     */ 
     private static final long serialVersionUID = 4278014816235716721L; 

     @Id 
     @GeneratedValue(strategy = GenerationType.IDENTITY) 
     @Column(name = "id", unique = true, nullable = false) 
     private Integer id; 

     @Column(name = "companyName", unique = true, nullable = false, length = 200) 
     private String companyName; 

     @Column(name = "companyLogo", unique = true, nullable = false, length = 10000) 
     private String companyLogo; 

     @Column(name = "isDefaultCompany",nullable = false) 
     private boolean isDefaultCompany; 

     @OneToMany(fetch = FetchType.LAZY, mappedBy = "company") 
     @Cascade({ CascadeType.DELETE, CascadeType.SAVE_UPDATE }) 
     @JsonIgnore 
     private Set<UserVO> users = new HashSet<UserVO>(0); 

    }

我的休息方法，返回公司通過JSON對象如下

/** 
    * Method to get the company for a particular userId 
    * @param userId 
    * @return 
    */ 
    @RequestMapping(value = { GET_COMPANY_FOR_USER }, method = RequestMethod.GET) 
    public CompanyVO getCompanyForUser(
      @PathVariable(value = RestConstants.USER_ID_PLACEHOLDER) Integer userId) { 

     LOG.info("Entered getCompanyForUser method - userId:{}", userId); 


     CompanyVO companyVO = companyServices.getCompanyForUser(userId); 

     LOG.info("Exiting getCompanyForUser method"); 
     return companyVO; 
    }

當我把這個特定的休息方法，我得到堆棧跟蹤下列錯誤

[2015-03-02 11:12:30,229] [http-bio-8080-exec-8] [INFO] com.test.webapp.controllers.rest.CompanyRestController - Entered getCompanyForUser method - userId:1 
[2015-03-02 11:12:30,248] [http-bio-8080-exec-8] [INFO] com.test.webapp.controllers.rest.CompanyRestController - Exiting getCompanyForUser method 
[2015-03-02 11:12:30,267] [http-bio-8080-exec-8] [INFO] c.t.webapp.controllers.exceptions.GlobalExceptionHandlerController - Entered exception method: e:{} 
org.springframework.http.converter.HttpMessageNotWritableException: Could not write content: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)) (through reference chain: com.test.domain.dao.CompanyVO_$$_jvstb99_6["handler"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)) (through reference chain: com.test.domain.dao.CompanyVO_$$_jvstb99_6["handler"]) 
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:238) ~[spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:208) ~[spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:161) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:101) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:202) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:71) ~[spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:777) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:706) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877) ~[spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966) [spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857) [spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:620) [servlet-api.jar:na] 
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842) [spring-webmvc-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) [servlet-api.jar:na] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.54] 
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat7-websocket.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.54] 
    at org.springframework.orm.hibernate4.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:150) [spring-orm-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.54] 
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:186) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE] 
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE] 
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344) [spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261) [spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.54] 
    at org.springframework.web.multipart.support.MultipartFilter.doFilterInternal(MultipartFilter.java:118) [spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [catalina.jar:7.0.54] 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [catalina.jar:7.0.54] 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [catalina.jar:7.0.54] 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) [catalina.jar:7.0.54] 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [catalina.jar:7.0.54] 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) [catalina.jar:7.0.54] 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) [tomcat-coyote.jar:7.0.54] 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) [tomcat-coyote.jar:7.0.54] 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) [tomcat-coyote.jar:7.0.54] 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_40] 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_40] 
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-coyote.jar:7.0.54] 
    at java.lang.Thread.run(Thread.java:724) [na:1.7.0_40] 
Caused by: com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)) (through reference chain: com.test.domain.dao.CompanyVO_$$_jvstb99_6["handler"]) 
    at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:59) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:26) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:505) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:639) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:114) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:1887) ~[jackson-databind-2.4.3.jar:2.4.3] 
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:231) ~[spring-web-4.1.4.RELEASE.jar:4.1.4.RELEASE] 
    ... 50 common frames omitted

在分揀這個任何援助將非常感激

來源

2015-03-02 Damien Gallagher

的http：//計算器。 com/questions/4362104/strange-jackson-exception-being-thrown-when-serializing-hibernate-object – 2015-03-02 11:19:50

-3

感謝葉夫根提供含有答案詮釋我CompanyVO豆與以下標註的鏈接刪除錯誤 @JsonIgnoreProperties（{「hibernateLazyInitializer」，「處理程序「}）

來源

2015-03-02 11:27:53

除了您已經找到的解決方案之外，您可以考慮兩種解決方案。一個註冊Hibernate4Module與ObjectMapper，這將註冊HibernateProxySerializer，已經配備智能處理代理，您可以檢查代碼不難理解。登記也相當簡單的，形成其文檔：

public class HibernateAwareObjectMapper extends ObjectMapper { 

    public HibernateAwareObjectMapper() { 
     registerModule(new Hibernate4Module()); 
    } 
}

比寄存器

<mvc:annotation-driven> 
     <mvc:message-converters> 
      <!-- Use the HibernateAware mapper instead of the default --> 
      <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> 
       <property name="objectMapper"> 
        <bean class="path.to.your.HibernateAwareObjectMapper" /> 
       </property> 
      </bean> 
     </mvc:message-converters> 
    </mvc:annotation-driven>

另一種解決方案是使用一個DTO對象，把從一個實體複製值時，一些鍋爐板代碼，但給你更多的控制和解耦來自實際實體的表示

來源

2015-03-02 11:34:15

根據masterSlave提供的鏈接和解決方案，我將它用於Spring Boot。我在我的Spring Boot項目中遇到了這個問題，並解決它以創建HibernateAwareObjectMapper並定義如下的自定義新的MappingJackson2HttpMessageConverter。

首先添加dependecy爲hibernate4到pom.xml的

<dependency> 
      <groupId>com.fasterxml.jackson.datatype</groupId> 
      <artifactId>jackson-datatype-hibernate4</artifactId> 
      <version>2.5.3</version> 
     </dependency>

創建HibernateAwareObjectMapper類

/** 
* https://github.com/FasterXML/jackson-datatype-hibernate 
* 
*/ 
public class HibernateAwareObjectMapper extends ObjectMapper { 

    /** 
    * 
    */ 
    private static final long serialVersionUID = 1L; 

    public HibernateAwareObjectMapper() { 
     registerModule(new Hibernate4Module()); 
    } 
}

添加自定義MappingJackson2HttpMessageConverter類Application.java

@Bean 
    public MappingJackson2HttpMessageConverter customJackson2HttpMessageConverter() { 
     MappingJackson2HttpMessageConverter jsonConverter = new MappingJackson2HttpMessageConverter(); 
     HibernateAwareObjectMapper hibernateAwareObjectMapper = new HibernateAwareObjectMapper(); 
     jsonConverter.setObjectMapper(hibernateAwareObjectMapper); 
     return jsonConverter; 
    } 

    @Override 
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { 
     converters.add(customJackson2HttpMessageConverter()); 
     super.addDefaultHttpMessageConverters(converters); 
    }

來源

2016-04-18 21:35:21 erhun

這不提供對發佈的問題的答案;這是一個「謝謝」，針對[以前的答案]（http://stackoverflow.com/a/28808817/1677912）。 [請僅使用Answers來回答問題]（// meta.stackoverflow.com/q/92107）。你已經獲得了足夠的[特權]（// stackoverflow.com/privileges）來支持你喜歡的答案，這就是堆棧溢出的方式來表達謝意。 – Mogsdad 2016-04-19 01:28:45

@Mogsdad根據Hibernate的問題，Spring和Jackson的用法會導致lazy initilization屬性出現一個問題，將其轉換爲傑克遜提供的json。 MasterSlave以Spring MVC的視角給出答案，所以我想作爲Spring Boot的解決方案。因爲我在Spring Boot上添加了一個自定義的MappingJackson2HttpMessageConverter實現用法，值得貢獻。我沒有找到任何其他的答案。如果它沒有得到任何upvote（這意味着對某人有用），我會很高興地刪除:)感謝您的評論。 – erhun 2016-04-19 06:25:53

請不要添加「謝謝」作爲答案。相反，投票答案，你覺得有幫助。 - [來自評論]（/ review/low-quality-posts/12063607） – 2016-04-19 06:59:18

春季休息 - 異常生產Json數據

回答

相關問題