我正在使用Spring和Hibernate来使用MySql数据库。在我的架构中，有一个与其他类有9连接的Acquisition类，我必须检索这个对象。
所以，我将我的所有提取类型设置为EAGER，并将@JsonIgnore放在集合集合上。
问题是性能，我有一个方法可以多次检索Acquisition对象和执行时间
iupr.setAcquisition(acquisitionServices.findById(idAcquisition));
太高了。 是否渴望输入问题？我该如何解决这个问题（使用lazy类型我无法检索类的所有对象，例如Car有CarType引用，我需要这个）。 我想到的唯一方法是在ArrayList中存储我的Acquisition对象，因为我在同一个类中创建它们，但我不喜欢这种方法。 你有建议吗？谢谢
这是实体类（省略的get和set方法）
采集
@Entity
@Table(name = "acquisition", catalog = "ats")
public class Acquisition implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer idAcquisition;
private Car car;
private DpfWeighting dpfWeighting;
private MissionProfile missionProfile;
private OilSample oilSample;
private Shift shift;
private SwVersion swVersion;
private Date date;
private float sessionDuration;
private int beginKm;
private int endKm;
private String driverName;
private String dataset;
private String drChannelsConf;
private String excelRow;
@JsonIgnore
private Set<Rdi> rdis = new HashSet<Rdi>(0);
@JsonIgnore
private Set<SelfLearning> selfLearnings = new HashSet<SelfLearning>(0);
@JsonIgnore
private Set<Iupr> iuprs = new HashSet<Iupr>(0);
SwVersion
@Entity
@Table(name = "swversion", catalog = "ats")
public class SwVersion implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private String idSwVersion;
private String note;
@JsonIgnore
private Set<Acquisition> acquisitions = new HashSet<Acquisition>(0);
RDI
@Entity
@Table(name = "rdi", catalog = "ats")
public class Rdi implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer idRdi;
private Acquisition acquisition;
private DefRdi defRdi;
private String value1;
private Integer value2;
private Float value3;
defRdi
@Entity
@Table(name = "defrdi", catalog = "ats")
public class DefRdi implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer idDefRdi;
private Ecu ecu;
private int sequence;
private String parName;
private String description;
private int valueType;
private String valueNull;
private String excelColumn;
private String note;
@JsonIgnore
private Set<Rdi> rdis = new HashSet<Rdi>(0);
public DefRdi() {
}
public DefRdi(Ecu ecu, int sequence, String parName, String description, int valueType, String excelColumn) {
this.ecu = ecu;
this.sequence = sequence;
this.parName = parName;
this.description = description;
this.valueType = valueType;
this.excelColumn = excelColumn;
}
public DefRdi(Ecu ecu, int sequence, String parName, String description, int valueType, String valueNull,
String excelColumn, String note, Set<Rdi> rdis) {
this.ecu = ecu;
this.sequence = sequence;
this.parName = parName;
this.description = description;
this.valueType = valueType;
this.valueNull = valueNull;
this.excelColumn = excelColumn;
this.note = note;
this.rdis = rdis;
}
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "id_defRdi", unique = true, nullable = false)
public Integer getIdDefRdi() {
return this.idDefRdi;
}
public void setIdDefRdi(Integer idDefRdi) {
this.idDefRdi = idDefRdi;
}
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "id_ecu", nullable = false)
public Ecu getEcu() {
return this.ecu;
}
public void setEcu(Ecu ecu) {
this.ecu = ecu;
}
@Column(name = "sequence", nullable = false)
public int getSequence() {
return this.sequence;
}
public void setSequence(int sequence) {
this.sequence = sequence;
}
@Column(name = "parName", nullable = false, length = 50)
public String getParName() {
return this.parName;
}
public void setParName(String parName) {
this.parName = parName;
}
@Column(name = "description", nullable = false, length = 100)
public String getDescription() {
return this.description;
}
public void setDescription(String description) {
this.description = description;
}
@Column(name = "valueType", nullable = false)
public int getValueType() {
return this.valueType;
}
public void setValueType(int valueType) {
this.valueType = valueType;
}
@Column(name = "valueNull", length = 3)
public String getValueNull() {
return this.valueNull;
}
public void setValueNull(String valueNull) {
this.valueNull = valueNull;
}
@Column(name = "excelColumn", nullable = false, length = 2)
public String getExcelColumn() {
return this.excelColumn;
}
public void setExcelColumn(String excelColumn) {
this.excelColumn = excelColumn;
}
@Column(name = "note", length = 100)
public String getNote() {
return this.note;
}
public void setNote(String note) {
this.note = note;
}
@OneToMany(fetch = FetchType.EAGER, mappedBy = "defRdi")
public Set<Rdi> getRdis() {
return this.rdis;
}
public void setRdis(Set<Rdi> rdis) {
this.rdis = rdis;
}
}
Ecu的
@Entity
@Table(name = "ecu", catalog = "ats")
public class Ecu implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private String idEcu;
private String note;
@JsonIgnore
private Set<DefSelfLearning> defSelfLearnings = new HashSet<DefSelfLearning>(0);
@JsonIgnore
private Set<DefRdi> defRdis = new HashSet<DefRdi>(0);
@JsonIgnore
private Set<DefIupr> defIuprs = new HashSet<DefIupr>(0);
@JsonIgnore
private Set<Fleet> fleets = new HashSet<Fleet>(0);
对于DefIupr和SelfLearning也是如此 懒惰不起作用，因为我使用jackson为我的webservice序列化对象，当我创建它时，我只检索内部对象的代理然后异常。我尝试使用Hibernate.initialize并创建两个方法，一个用于非序列化查询，另一个用于所有相关对象（使用hibernate.initialize），但不能用于相同的异常
@Override
@Transactional
public List<Car> findByFleetIdFleet(int idFleet) {
List<Car> carList= carRepository.findByFleetIdFleet(idFleet);
for (Car car:carList){
Hibernate.initialize(car.getCarType());
Hibernate.initialize(car.getFleet());
}
return carList;
}
例外：
ERROR com.controller.ErrorController - 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.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst6c2_f["handler"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: com.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst6c2_f["handler"])
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:271)
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:100)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:167)
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:100)
at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:166)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:80)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:127)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:806)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:729)
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:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1526)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1482)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
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.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst6c2_f["handler"])
at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:59)
at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:26)
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:505)
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:639)
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:505)
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:639)
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:100)
at com.fasterxml.jackson.databind.ser.impl.IndexedListSerializer.serializeContents(IndexedListSerializer.java:21)
at com.fasterxml.jackson.databind.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:183)
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:505)
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:639)
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:152)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:128)
at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:602)
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:264)
... 37 more
.17:32:45.577 [http-nio-8086-exec-4] WARN o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Handler execution resulted in exception: 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.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst6c2_f["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.model.tablesField.TableUI["data"]->java.util.ArrayList[0]->com.domain.Car["carType"]->com.domain.CarType_$$_jvst6c2_f["handler"])