Spring Hibernate不总是获取子数据
我有两个表设备和规则,一个设备可以有n个规则,所以它们存在于一对多的关联中,反之亦然 我使用的是Spring+Hibernate+REST,当我获取设备数据时,我从不想获取规则数据,当我使用lazy fetch时,我获取的是lazy初始化异常。我正在通过注释进行hibernate映射。请建议一些方法,在检索设备数据时可以跳过规则数据的检索 请在下面查找我的课程:Spring Hibernate不总是获取子数据,hibernate,jpa,spring-data,lazy-loading,one-to-many,Hibernate,Jpa,Spring Data,Lazy Loading,One To Many,我有两个表设备和规则,一个设备可以有n个规则,所以它们存在于一对多的关联中,反之亦然 我使用的是Spring+Hibernate+REST,当我获取设备数据时,我从不想获取规则数据,当我使用lazy fetch时,我获取的是lazy初始化异常。我正在通过注释进行hibernate映射。请建议一些方法,在检索设备数据时可以跳过规则数据的检索 请在下面查找我的课程: @Entity @Table(name="device") @DynamicUpdate @SelectBeforeUpdate pu
@Entity
@Table(name="device")
@DynamicUpdate
@SelectBeforeUpdate
public class Devices implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@Column(name="DEVICE_ID")
private Integer deviceId;
@Column(name="DEVICE_DESC")
private String deviceDesc;
@Column(name="DEVICE_NAME")
private String deviceName;
@OneToMany(mappedBy="device",fetch = FetchType.LAZY)
@JsonIgnore
private List<Rules> rules;
public Devices() {
}
public Integer getDeviceId() {
return this.deviceId;
}
public void setDeviceId(Integer deviceId) {
this.deviceId = deviceId;
}
public List<Rules> getRules() {
return this.rules;
}
public void setRules(List<Rules> rules) {
this.rules = rules;
}
}
请在下面查找异常:
SEVERE: Servlet.service() for servlet [mvc-dispatcher] in context with path [/MyWork] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.beans.Devices.rules, no session or session was closed] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.beans.Devices.rules, no session or session was closed
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:393)
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:385)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:378)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:112)
at org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:266)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:95)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:99)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:219)
at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:99)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:219)
at com.google.gson.Gson.toJson(Gson.java:600)
at com.google.gson.Gson.toJson(Gson.java:579)
at org.springframework.http.converter.json.GsonHttpMessageConverter.writeInternal(GsonHttpMessageConverter.java:199)
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:100)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:222)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:153)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:165)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:80)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
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:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
您正在事务中读取
设备
,此时规则
被代理。阅读
当您尝试device.getRules()
(位于com.google.gson.gson.toJson(gson.java:579)
在堆栈跟踪中)事务已经完成,并且Rule
仍然未提取,无法再提取
您需要确保在事务完成之前初始化规则,或使其立即加载
另请阅读您得到了什么异常?@正如在上面的问题中找到异常日志一样……您可以在序列化之前取消固定对象,只需排除Hibernate.initialize(实体);避免收集的线路init@StanislavL你能告诉我在哪里必须调用unproxy方法吗?或者它是一个被重写的方法吗?我问这个问题是因为我正在使用Spring+hibernateCheck谢谢你的回答,这是否可能使devices.getRules()在Json转换期间不被调用。i、 e通过任何注释避免结果Json中设备的规则部分??顺便说一句,我试过使用@JsonIgnore,这对我没有帮助。我没有使用GSON库的经验,但你可以看看。令人惊讶的是,格森似乎没有类似于杰克逊的东西,我可能错了,这很好。您使用的是JPA@Transient还是GSON注释(如果有的话)?
SEVERE: Servlet.service() for servlet [mvc-dispatcher] in context with path [/MyWork] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.beans.Devices.rules, no session or session was closed] with root cause
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.beans.Devices.rules, no session or session was closed
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:393)
at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:385)
at org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:378)
at org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:112)
at org.hibernate.collection.internal.PersistentBag.iterator(PersistentBag.java:266)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:95)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:99)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:219)
at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:99)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:219)
at com.google.gson.Gson.toJson(Gson.java:600)
at com.google.gson.Gson.toJson(Gson.java:579)
at org.springframework.http.converter.json.GsonHttpMessageConverter.writeInternal(GsonHttpMessageConverter.java:199)
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:100)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:222)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:153)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:165)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:80)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:126)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
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:621)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)