@Entity
@NamedQuery(name = "findAllCustomer", query = "SELECT i FROM Customer i")
public class Customer implements Serializable {
private static final long serialVersionUID = 1L;
@Id
private int id;
private String firstName;
private String lastName;
private String address;
@OneToMany(cascade=ALL, mappedBy="customer")
private Collection<Rent> rent;
public Customer(){
}
public Customer(int id,String firstName, String lastName, String address){
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.address = address;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getFirstName(){
return firstName;
}
public void setFirstName(String firstName){
this.firstName = firstName;
}
public String getLastName(){
return lastName;
}
public void setLastName(String lastName){
this.lastName = lastName;
}
public String getAddress(){
return address;
}
public void setAddress(String address){
this.address = address;
}
public Collection<Rent> getRent() {
return rent;
}
public void setRent(Collection<Rent> rent) {
this.rent = rent;
}
public void addRent(Rent rent) {
this.getRent().add(rent);
}
}
*
@Entity
@NamedQuery(name = "findAllRent", query = "SELECT i FROM Rent i")
public class Rent implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String item;
private int days;
private int rDate;
@JoinColumn(name="VENDORID")
@ManyToOne
private Customer customer;
public Rent(){
}
public Rent(String item, int days, int rDate){
this.item = item;
this.days = days;
this.rDate= rDate;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getItem() {
return item;
}
public void setItem(String item) {
this.item = item;
}
public int getDays() {
return days;
}
public void setDays(int days ) {
this.days = days;
}
public int getRDate() {
return rDate;
}
public void setRDate(int rDate ) {
this.rDate = rDate;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
}
public void createRent (int currentCustomer,String item, int days, int rDate ){
Customer customer = em.find(Customer.class, currentCustomer);
Rent rent = new Rent(item, days, rDate);
customer.addRent(rent);
rent.setCustomer(customer);
em.merge(customer);
}
//currentCustomer has the id of the customer for whom the rent is being created//
public int getCurrentCustomer() {
return currentCustomer;
}
public void setCurrentCustomer(int currentCustomer) {
this.currentCustomer = currentCustomer;
}
public String doCreateRent() {
System.out.println(""+currentCustomer);
try {
customerEJB.createRent(this.currentCustomer, this.item, this.days, this.rDate);
} catch (Exception e) {
System.out.printf( "Problem adding line items to order ID {0}");
}
return "listRent.xhtml";
}
<h:head>
<title>List all the customer</title>
</h:head>
<h:body>
<h1>List all the customer</h1>
<hr/>
<h:dataTable value="#{customerController.customerList}" var="it" border="1">
<h:column>
<f:facet name="header">
<h:outputText value="Id"/>
</f:facet>
我认为这是我搞乱应用程序的地方
<h:form>
<h:commandLink id="customer_Id_link" action="newRent.xhtml">
<h:outputText value="#{it.id}"/>
<f:setPropertyActionListener target="#{customerController.currentCustomer}" value="#{it.id}" />
</h:commandLink>
</h:form>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="FirstName"/>
</f:facet>
<h:outputText value="#{it.firstName}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="LastName"/>
</f:facet>
<h:outputText value="#{it.lastName}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Address"/>
</f:facet>
<h:outputText value="#{it.address}"/>
</h:column>
</h:dataTable>
<h:form>
<h:link outcome="index.xhtml" value="mainpage"/>
</h:form>
<hr/>
<i>APress - Beginning Java EE 6</i>
</h:body>
</html>
<h:head>
<title>Creates a new rent</title>
</h:head>
<h:body>
<h1>Create a new rent</h1>
<hr/>
<h:form>
<table border="0">
<tr>
<td>
<h:outputLabel value="Item : "/>
</td>
<td>
<h:inputText value="#{customerController.item}"/>
</td>
</tr>
<tr>
<td>
<h:outputLabel value="days : "/>
</td>
<td>
<h:inputText value="#{customerController.days}"/>
</td>
</tr>
<tr>
<td>
<h:outputLabel value="Date : "/>
</td>
<td>
<h:inputText value="#{customerController.RDate}"/>
</td>
</tr>
</table>
<h:commandButton value="Create a rent" action="#{customerController.doCreateRent()}"/>
</h:form>
<hr/>
<i>APress - Beginning Java EE 6</i>
</h:body>
</html>
INFO: currentcustomer0
WARNING: EJB5184:A system exception occurred during an invocation on EJB CustomerEJB, method: public void shoeb.CustomerEJB.createRent(int,java.lang.String,int,int)
WARNING: javax.ejb.EJBException
at com.sun.ejb.containers.BaseContainer.processSystemException(BaseContainer.java:5215)
at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:5113)
at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4901)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2045)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1994)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:222)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:89)
at com.sun.proxy.$Proxy185.createRent(Unknown Source)
at shoeb.__EJB31_Generated__CustomerEJB__Intf____Bean__.createRent(Unknown Source)
at shoeb.CustomerController.doCreateRent(CustomerController.java:57)
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:606)
at javax.el.BeanELResolver.invokeMethod(BeanELResolver.java:779)
at javax.el.BeanELResolver.invoke(BeanELResolver.java:528)
at javax.el.CompositeELResolver.invoke(CompositeELResolver.java:257)
at com.sun.el.parser.AstValue.invoke(AstValue.java:248)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:302)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
at shoeb.CustomerEJB.createRent(CustomerEJB.java:45)
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:606)
at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1052)
at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1124)
at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:5388)
at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:619)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:800)
at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:571)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doAround(SystemInterceptorProxy.java:162)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:144)
at sun.reflect.GeneratedMethodAccessor78.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:861)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:800)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:370)
at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:5360)
at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:5348)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:214)
... 47 more
INFO: Problem adding line items to order ID {0}
答案 0 :(得分：0)
试试这个：
public void createRent (int currentCustomer,String item, int days, int rDate ){
try{
Customer customer = em.find(Customer.class, currentCustomer);
Rent rent = new Rent(item, days, rDate);
customer.addRent(rent);
rent.setCustomer(customer);
em.merge(customer);
} catch (Exception e) {
throw new EJBException(e.getMessage());
}
}
由于关系是双向的，因此您需要为彼此指定实体。 这是：
If the OneToMany uses a foreign key in the target object's table JPA
requires that the relationship be bi-directional
(inverse ManyToOne relationship must be defined in the target object),
and the source object must use the mappedBy attribute to define the mapping
和链接： http://en.wikibooks.org/wiki/Java_Persistence/OneToMany