我需要帮助我迷失了这个错误。当我点击添加新城市的提交时，我遇到了选择菜单转换器的问题。
这是我的 Facelets
<p:commandButton value="New city" update=":form:display" id="withIcon" onclick="newvilledialog.show()" title="Nouveau"/>
<p:dialog header="Nouveau ville" widgetVar="newvilledialog" resizable="false" id="newvilleDlg"
showEffect="fade" hideEffect="explode" modal="true">
<h:panelGrid id="panel" columns="2" cellpadding="4" style="margin:0 auto;">
<h:outputLabel for="pays" value="Pays :" />
<h:selectOneMenu value="#{villeBean.villeList}">
<f:converter converterId="paysConverter"></f:converter>
<f:selectItem itemLabel="select Pays" itemValue="" />
<f:selectItems value="#{paysBean.paysList}" var="pays" itemLabel="#{pays.nompays}" itemValue="#{pays}"/>
</h:selectOneMenu>
<h:outputLabel for="nomville" value="Nom ville :" />
<p:inputText id="nomville1" value="#{villeBean.nomville}" />
<p:commandButton id="Buttonnew" value="Valider" action="#{villeBean.addVille}" update="form" oncomplete="newvilledialog.hide();"/>
</h:panelGrid>
</p:dialog>
类 Pays.java
package ma.project.sgcheque.model;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
/**
* Pays entity. @author MyEclipse Persistence Tools
*/
@Entity
@Table(name = "pays", catalog = "base_cheque")
public class Pays implements java.io.Serializable {
// Fields
private Integer idpays;
private String nompays;
private Set<Ville> villes = new HashSet<Ville>(0);
// Constructors
/** default constructor */
public Pays() {
}
/** full constructor */
public Pays(String nompays, Set<Ville> villes) {
this.nompays = nompays;
this.villes = villes;
}
// Property accessors
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "idpays", unique = true, nullable = false)
public Integer getIdpays() {
return this.idpays;
}
public void setIdpays(Integer idpays) {
this.idpays = idpays;
}
@Column(name = "nompays", length = 45)
public String getNompays() {
return this.nompays;
}
public void setNompays(String nompays) {
this.nompays = nompays;
}
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "pays")
public Set<Ville> getVilles() {
return this.villes;
}
public void setVilles(Set<Ville> villes) {
this.villes = villes;
}
public boolean equals(Object other) {
return other instanceof Pays && (idpays != null) ? idpays.equals(((Pays) other).idpays) : (other == this);
}
}
转换器：
package com.project.sgcheque.web.converters;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.FacesConverter;
import java.util.List;
import ma.project.sgcheque.model.Pays;
@FacesConverter(forClass=Pays.class, value="paysConverter")
public class PaysConverter implements Converter {
public List<Pays> paysList;
public Object getAsObject(FacesContext context, UIComponent component, String value) {
try{
if (value.trim().equals("")) {
return null;
} else {
for (Pays p : paysList) {
if (p.getIdpays().equals(value)) {
return p;
}
}
}}catch (NullPointerException ex){}
return null;
}
public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
try {
Pays pays = (Pays) value;
return pays.getIdpays() != null ? String.valueOf(pays.getIdpays()) : null;
}catch (NullPointerException exception) {
return null;
}catch (ClassCastException exception) {
return null;
}
}
}
和我的 Bean (PaysManagedBean)
package ma.project.sgcheque.managed.bean;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.RequestScoped;
import org.springframework.dao.DataAccessException;
import ma.project.sgcheque.model.Pays;
import ma.project.sgcheque.model.Ville;
import ma.project.sgcheque.service.interfaces.IVilleService;
@ManagedBean(name="villeBean")
@RequestScoped
public class VilleManagedBean implements Serializable {
private static final long serialVersionUID = 1L;
private static final String SUCCESS = "success";
private static final String ERROR = "error";
//Spring Ville Service is injected...
@ManagedProperty(value="#{VilleService}")
IVilleService villeService;
List<Ville> villeList;
private Ville selectedVille = new Ville();
private int idville;
private String nomville;
private Pays pays = new Pays();
/**
* Add Ville
*
* @return String - Response Message
*/
public String addVille() {
try {
Ville ville = new Ville();
ville.setIdville(getIdville());
ville.setNomville(getNomville());
ville.setPays(getPays());
getVilleService().addVille(ville);
return "ville";
} catch (DataAccessException e) {
e.printStackTrace();
}
return ERROR;
}
/**
* Update Pays
*
* @return String - Response Message
*/
public String updateVille() {
getVilleService().updateVille(selectedVille);
return "ville";
}
public String update(){
villeService.save(selectedVille);
return null;
}
/**
* Delete Pays
*
* @return String - Response Message
*/
public String deleteVille() {
try {
getVilleService().deleteVille(selectedVille);
return "ville";
} catch (DataAccessException e) {
e.printStackTrace();
}
return ERROR;
}
/**
* Reset Fields
*
public void reset() {
this.setIdville(0);
this.setNomville("");
this.setPays(null);
}*/
/**
* Get Ville Service
*
* @return IVilleService - Ville Service
*/
public IVilleService getVilleService() {
return villeService;
}
/**
* Set Ville Service
*
* @param IVilleService - Ville Service
*/
public void setVilleService(IVilleService villeService) {
this.villeService = villeService;
}
public List<Ville> getVilleList() {
villeList = new ArrayList<Ville>();
villeList.addAll(getVilleService().getVille());
return villeList;
}
public void setVilleList(List<Ville> villeList) {
this.villeList = villeList;
}
/**
* Get SelectedVille Id
*
* @return selectedVille
*/
public Ville getSelectedVille() {
return selectedVille;
}
/**
* Set SelectedVille Id
*
* @return selectedVille
*/
public void setSelectedVille(Ville selectedVille) {
this.selectedVille = selectedVille;
}
/**
* Get Ville Id
*
* @return int - Ville Id
*/
public int getIdville() {
return idville;
}
/**
* Set Ville Id
*
* @param int - Ville Id
*/
public void setIdville(int idville) {
this.idville = idville;
}
/**
* Get Ville Name
*
* @return String - Ville Name
*/
public String getNomville() {
return nomville;
}
/**
* Set Ville Name
*
* @param String - Ville Name
*/
public void setNomville(String nomville) {
this.nomville = nomville;
}
/**
* Get Pays Object
*
* @return String - Pays Object
*/
public Pays getPays() {
return pays;
}
/**
* Set Pays Object
*
* @return String - Pays Object
*/
public void setPays(Pays pays) {
this.pays = pays;
}
}
这就是错误
javax.faces.FacesException: #{villeBean.addVille}: org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:85)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:97)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:114)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:308)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:722)
Caused by: javax.faces.FacesException: #{villeBean.addVille}: org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:114)
at javax.faces.component.UICommand.broadcast(UICommand.java:311)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:781)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1246)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:77)
... 15 more
Caused by: javax.faces.el.EvaluationException: org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:98)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:98)
... 19 more
Caused by: org.springframework.dao.InvalidDataAccessApiUsageException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays; nested exception is org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:654)
at org.springframework.orm.hibernate3.HibernateTransactionManager.convertHibernateAccessException(HibernateTransactionManager.java:793)
at org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:664)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:120)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy20.addVille(Unknown Source)
at ma.project.sgcheque.managed.bean.VilleManagedBean.addVille(VilleManagedBean.java:52)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.el.parser.AstValue.invoke(AstValue.java:131)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:102)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:84)
... 20 more
Caused by: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: ma.project.sgcheque.model.Pays
at org.hibernate.engine.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:242)
at org.hibernate.type.EntityType.getIdentifier(EntityType.java:430)
at org.hibernate.type.ManyToOneType.isDirty(ManyToOneType.java:265)
at org.hibernate.type.TypeFactory.findDirty(TypeFactory.java:619)
at org.hibernate.persister.entity.AbstractEntityPersister.findDirty(AbstractEntityPersister.java:3141)
at org.hibernate.event.def.DefaultFlushEntityEventListener.dirtyCheck(DefaultFlushEntityEventListener.java:501)
at org.hibernate.event.def.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:227)
at org.hibernate.event.def.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:150)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:219)
at org.hibernate.event.def.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:99)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:49)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
at org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:656)
... 36 more
当我点击添加新城市的提交时出现错误（谁支付（国家）作为外键）。
对不起我的英语，但我希望你明白我的问题是什么。真的停止了。