我有一个小问题,我不知道该如何解决。请问你能帮帮我吗?当我尝试保留实体时,出现下一个异常:
12:47:39,398 ERROR [org.black.dmitriy.entityHome.ScheduleHome] (http--127.0.0.1-8080-1) javax.persistence.EntityExistsException: a different object with the same identifier value was already associated with the session: [org.black.dmitriy.entity.Schedule#1]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1333) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1289) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1295) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:859) [hibernate-entitymanager-4.0.1.Final.jar:4.0.1.Final]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.seam.persistence.EntityManagerInvocationHandler.invoke(EntityManagerInvocationHandler.java:46) [jboss-seam.jar:2.3.0.Final]
at $Proxy81.persist(Unknown Source) at org.jboss.seam.framework.EntityHome.persist(EntityHome.java:84) [jboss-seam.jar:2.3.0.Final]
at org.black.dmitriy.entityHome.ConversationHome.tryPersist(ConversationHome.java:147) [ejb.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.RollbackInterceptor.aroundInvoke(RollbackInterceptor.java:28) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.core.ConversationInterceptor.aroundInvoke(ConversationInterceptor.java:65) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.TransactionInterceptor$1.work(TransactionInterceptor.java:97) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.util.Work.workInTransaction(Work.java:61) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.transaction.TransactionInterceptor.aroundInvoke(TransactionInterceptor.java:91) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:186) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:104) [jboss-seam.jar:2.3.0.Final]
at org.black.dmitriy.entityHome.ScheduleHome_$$_javassist_seam_8.tryPersist(ScheduleHome_$$_javassist_seam_8.java) [ejb.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_04]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_04]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_04]
at java.lang.reflect.Method.invoke(Method.java:601) [rt.jar:1.7.0_04]
at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:335) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.util.ReflectionUtil.invokeMethod(ReflectionUtil.java:348) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.parser.AstPropertySuffix.invoke(AstPropertySuffix.java:58) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.parser.AstValue.invoke(AstValue.java:96) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at org.jboss.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276) [jboss-el-1.0_02.CR6.jar:1.0_02.CR6]
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.component.UICommand.broadcast(UICommand.java:315) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.1.7-jbossorg-2.jar:]
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) [jsf-impl-2.1.7-jbossorg-2.jar:]
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) [jboss-jsf-api_2.1_spec-2.0.1.Final.jar:2.0.1.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) [jboss-seam.jar:2.3.0.Final]
at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158) [jboss-seam.jar:2.3.0.Final]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:161) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:397) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.jpa.interceptor.WebNonTxEmCloserValve.invoke(WebNonTxEmCloserValve.java:50) [jboss-as-jpa-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:153) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:368) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877) [jbossweb-7.0.13.Final.jar:]
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:671) [jbossweb-7.0.13.Final.jar:]
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:930) [jbossweb-7.0.13.Final.jar:]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_04]
我使用接缝2.3,进入休眠状态。我的import.sql文件中有一个插入语句:
INSERT INTO Schedules (id, name, dayCount, lessonCount, firstTermSize, secondTermSize, subgroupSize) VALUES(1, '2012/2013', 5, 8, 9, 9, 18)
它在表Schedule中插入一个实体。
然后,我使用EntityHome创建新的Schedule实体投放网页
@Name("scheduleHome")
@Scope(ScopeType.CONVERSATION)
public class ScheduleHome extends ConversationHome<Schedule> {
private static final long serialVersionUID = 1L;
public ScheduleHome() {
}
@Override
protected boolean isUnique() {
Schedule schedule = getInstance();
Schedule foundSchedule = ScheduleDAO.instance().getByName(schedule.getName());
if ((foundSchedule != null) && (!foundSchedule.equals(schedule))) {
showExistsErrorMessage(getInstance().getName());
return false;
}
return true;
}
@Override
protected Schedule createInstance() {
return new Schedule();
}
@Override
public String getEditOutcome() {
return "scheduleEdit";
}
@Override
protected void prepareEntityForSaving() {
}
}
和超类
public abstract class ConversationHome<T> extends EntityHome<T> {
private static final long serialVersionUID = 1L;
private String parentView;
public boolean isParentViewExists() {
return parentView != null && parentView.length() > 0;
}
public void setParentView(String parentView) {
this.parentView = parentView;
}
public String getParentView() {
return parentView;
}
public abstract String getEditOutcome();
protected abstract void prepareEntityForSaving();
protected abstract boolean isUnique();
@Override
@Create
public void create() {
create(false);
}
protected void create(boolean createNestedConversation) {
Conversation conversation = Conversation.instance();
if (!createNestedConversation && conversation.isLongRunning()) {
getLog().debug("conversation already started, nested will not create(isLongRunning = #0, isNested = #1)", conversation.isLongRunning(), conversation.isNested());
} else {
conversation.begin(false, conversation.isLongRunning());
conversation.changeFlushMode(FlushModeType.MANUAL);
getLog().debug("create(isLongRunning = #0, isNested = #1, id = #2)", conversation.isLongRunning(), conversation.isNested(), conversation.getId());
}
super.create();
}
private boolean init(Long id) {
FacesContext context = FacesContext.getCurrentInstance();
setParentView(Pages.getViewId(context));
if (id != null) {
setId(id);
try {
getInstance();
getLog().debug("instance initialized #0", getInstance());
} catch (EntityNotFoundException e) {
getLog().error(e);
return false;
}
}
return true;
}
public String startEdit(Long id) {
getLog().debug("start editing #0", id);
if (init(id)) {
return getEditOutcome();
} else {
return cancel();
}
}
public String cancel() {
if (isManaged()) {
getEntityManager().refresh(getInstance());
}
return returnToParent();
}
@End
protected String returnToParent() {
if (isParentViewExists()) {
Conversation conversation = Conversation.instance();
getLog().debug("end conversation(id = #0, isLongRunning = #1, isNested = #2)",
conversation.getId(), conversation.isLongRunning(), conversation.isNested());
conversation.end(true);
return getParentView();
} else {
clearInstance();
return null;
}
}
public String tryPersist() {
if (isUnique()) {
try {
prepareEntityForSaving();
String outcome = persist();
if (!"failed".equals(outcome)) {
return returnToParent();
}
} catch (Exception e) {
getLog().error(getInstance(), e);
showSaveErrorMessage(e);
}
}
return "failed";
}
}
当我尝试坚持下去时,我得到了这个例外。和网页上的消息
使用消息保存错误:具有相同标识符值的另一个对象已与该会话关联:[org.black.dmitriy.entity.Schedule#1]
它使休眠将id属性设置为1,但是我已经有了的实体id = 1
,因为我手动创建了它,并抛出了import.sql。
这是我的Schedule实体:
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
@Entity
@Table(name = "Schedules")
public class Schedule {
@Id
@GeneratedValue
@Column(name = "id", nullable = false)
private Long id;
@NotNull
@Column(name = "name", nullable = false, length = 40)
private String name;
@Column(name = "dayCount")
private int dayCount = 5;
@Column(name = "lessonCount")
private int lessonCount = 8;
@Column(name = "firstTermSize")
private int firstTermSize = 9;
@Column(name = "secondTermSize")
private int secondTermSize = 9;
@Column(name = "subgroupSize")
private int subgroupSize = 18;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, targetEntity = Faculty.class)
private List<Faculty> faculties = new ArrayList<>();
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, targetEntity = Building.class)
private List<Building> buildings = new ArrayList<>();
public Schedule() {
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getDayCount() {
return dayCount;
}
public void setDayCount(int dayCount) {
this.dayCount = dayCount;
}
public int getLessonCount() {
return lessonCount;
}
public void setLessonCount(int lessonCount) {
this.lessonCount = lessonCount;
}
public int getFirstTermSize() {
return firstTermSize;
}
public void setFirstTermSize(int firstTermSize) {
this.firstTermSize = firstTermSize;
}
public int getSecondTermSize() {
return secondTermSize;
}
public void setSecondTermSize(int secondTermSize) {
this.secondTermSize = secondTermSize;
}
public int getSubgroupSize() {
return subgroupSize;
}
public void setSubgroupSize(int subgroupSize) {
this.subgroupSize = subgroupSize;
}
public List<Faculty> getFaculties() {
return faculties;
}
public void setFaculties(List<Faculty> faculties) {
this.faculties = faculties;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof Schedule)) {
return false;
}
Schedule other = (Schedule) obj;
if (id == null) {
if (other.id != null) {
return false;
}
} else if (!id.equals(other.id)) {
return false;
}
return true;
}
@Override
public String toString() {
return this.name;
}
}
如您所见,id属性上有@GeneratedValue批注,所以我认为hibernate应该自己生成id,hibernate应该知道数据库中有id =
1的实体,并在newEntity = 2中设置了id。但是Hibernate设置了id在新实体中加入1.。能否请我停顿一下?
问题是hibernate如何生成您id
的,它从1开始。当它将1分配给对象之前,将其保存到数据库中时,它会看到数据库中已经存在具有相同ID的行,并导致异常。这个问题的简单自然的解决方案就是限制休眠,以便它不能1
作为ID分配给相关类的任何对象(在您的情况下)。
mySql的解决方案:
如果使用的是mySql,则可以手动创建表并设置自动增量,例如:
CREATE TABLE IF NOT EXISTS `testTable` (
`id` number(11) NOT NULL AUTO_INCREMENT,
...,
...,
...,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2; //assigning id by hibernate, will start from 2.
并且在您的域类中,您可以像下面这样对id进行注释:
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "ID")
public long getId() {
....
}
GenerationType.AUTO
默认情况下,在mySql中使用自动递增。并在设置AUTO_INCREMENT=2
休眠状态后开始分配ID的来源2
(因此1
被跳过)。
Oracle解决方案:
如果您限制休眠使用“序列”,并将序列的初始点设置为您希望的值,则对于oracle可以完成相同的操作。您可以像下面这样创建一个从头开始2
并递增的序列1
:
create sequence idSequence
start with 2
increment by 1
maxvalue 9999999999999;
您可以指定要用来生成域类对象的ID的序列,例如波纹管:
@Id
@SequenceGenerator(name = "idGeneratorSeq", sequenceName = "idSequence")
@GeneratedValue(strategy = GenerationType.AUTO, generator = "idGeneratorSeq")
@Column(name = "ID")
public long getId() {
....
}
这样您的问题就解决了。
问题内容: 在使用Spring和Hibernate的应用程序中,我解析CSV文件,并在每次从CSV文件中读取记录时通过调用来填充db 。 我的域模型: “家庭”有很多“子家庭” “子家庭”有很多“位置” “ Locus”属于“ Species” 都是双向映射。 码: 使用以下方法将物种分配给场所,该方法仅访问DAO层: Hibernate给出以下错误: 有小费吗? 问题答案: 使用。该异常表示当前
问题内容: 我有两个用户对象,而在尝试使用以下方法保存对象时 我收到以下错误: 我正在使用创建会话 我还尝试过在保存之前进行操作,但仍然没有运气。 这是我第一次在用户请求到来时获取会话对象,因此我要为什么要说该对象存在于会话中。 有什么建议么? 问题答案: 我已经多次发生此错误,很难追踪… 基本上,hibernate是指您有两个具有相同标识符(相同主键)但不是相同对象的对象。 我建议您分解代码,即
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此方法以事务开头 这是一个映射器类,我在其中创建DB帐户实体并映射地址和联系人。 当我不在地图内调用下面的方法时,一切都正常工作。但是当我调用它时,我得到了标题中描述的错误。 最后的方法是 异常堆栈跟踪 null
我有以下问题: 有人对此有解释吗?我考虑从我的业务服务中的hibernate会话中重新加载对象,并从Struts HTTP会话中复制实体对象中的数据。 Hibernate映射
null 对于我的数据,我有时会遇到这样的问题:A有一组不同的B对象,而这些B对象引用同一个C对象。 当我调用时,我会得到一个hibernate错误:。我知道hibernate不能在同一个会话中插入/更新/删除同一个对象两次,但是有什么方法可以解决这个问题吗?这似乎并不是一种罕见的情况。 在我研究这个问题的过程中,我看到有人建议使用,但当我这样做时,任何“冲突”对象都会作为所有值都设置为null的