我正在使用hibernate JPA的双向OnetoMany关系。
我得到一个空指针异常，即使我正在使用fetchtype.Eager并且同一段代码在一个rest方法中工作但不在另一个方法中工作？
CODE
用户
public class Users implements Serializable {
/** other fields **/
@OneToMany(cascade = CascadeType.ALL, mappedBy = "users", fetch = FetchType.EAGER)
private Collection<Tokens> tokensCollection;
/** getters and setters for other fields **/
@XmlTransient
public Collection<Tokens> getTokensCollection() {
return tokensCollection;
}
public void setTokensCollection(Tokens token) {
if (!token.getUser().equals(this.Userid)) {
token.setUser(this);
}
this.tokensCollection.add(token);
}
}
令牌
public class Tokens implements Serializable {
/** other fields **/
@JoinColumn(name = "userid", referencedColumnName = "userid")
@ManyToOne(optional = false, fetch = FetchType.EAGER)
private Users users;
/** getters and setters for other fields **/
@XmlTransient
public Users getUsers() {
return users;
}
public void setUsers(Users users) {
if (!users.getTokensCollection().contains(this)) {
users.getTokensCollection().add(this);
}
this.users = users;
}
}
我有两个休息方法，一个有一个JMS队列来设置用户并在插入用户后插入一个临时令牌（不确定因为我在使用setter和getter时得到了NPE所以我试图首先插入用户然后创建一个令牌然后匹配它们，如下所示。另一个是在成功授权时插入令牌的身份验证点。如果这不是最佳实践或性能问题是毁灭性的，我愿意改变我设置实体的方式。
插入方法
Users user = rfl.getUserByUsername(username);
Tokens tkn = new Tokens();
tkn.setJWT(token);
tkn.setUsers(user);
//not sure if this is making a difference cos I read somewhere that lazily loading is only impacted once you iterate over the collection but it doesn't make a difference cos a) im using eager and b) it works in one place but not the other
Collection<Tokens> tokenss = user.getTokensCollection();
for (Tokens token1 : tokenss) {
System.out.println("User:" + token1.getUsers());
}
//rfl is my ejb facade responsible for entity management i.e. merge, persist, remove, find, flush
rfl.edit(user);
LOG
2015-08-24 19:29:31,241 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) java.lang.NullPointerException
2015-08-24 19:29:31,241 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at ejb.Tokens.setUsers(Tokens.java:125)
2015-08-24 19:29:31,242 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at ejb.RegisterUserQueue.onMessage(RegisterUserQueue.java:72)
2015-08-24 19:29:31,242 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2015-08-24 19:29:31,242 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
2015-08-24 19:29:31,243 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
2015-08-24 19:29:31,243 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at java.lang.reflect.Method.invoke(Method.java:483)
2015-08-24 19:29:31,243 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
2015-08-24 19:29:31,244 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,244 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53)
2015-08-24 19:29:31,244 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
2015-08-24 19:29:31,245 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,245 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:407)
2015-08-24 19:29:31,246 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:82)
2015-08-24 19:29:31,246 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.processInvocation(Jsr299BindingsInterceptor.java:93)
2015-08-24 19:29:31,246 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
2015-08-24 19:29:31,247 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,247 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53)
2015-08-24 19:29:31,247 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
2015-08-24 19:29:31,248 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,248 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.invocationmetrics.ExecutionTimeInterceptor.processInvocation(ExecutionTimeInterceptor.java:43)
2015-08-24 19:29:31,248 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,249 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:407)
2015-08-24 19:29:31,249 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:55)
2015-08-24 19:29:31,250 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:83)
2015-08-24 19:29:31,250 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,250 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45)
2015-08-24 19:29:31,251 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,251 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InitialInterceptor.processInvocation(InitialInterceptor.java:21)
2015-08-24 19:29:31,252 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,252 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
2015-08-24 19:29:31,252 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.interceptors.ComponentDispatcherInterceptor.processInvocation(ComponentDispatcherInterceptor.java:53)
2015-08-24 19:29:31,253 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,253 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.pool.PooledInstanceInterceptor.processInvocation(PooledInstanceInterceptor.java:51)
2015-08-24 19:29:31,253 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,254 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInCallerTx(CMTTxInterceptor.java:251)
2015-08-24 19:29:31,254 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:342)
2015-08-24 19:29:31,254 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:239)
2015-08-24 19:29:31,255 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,255 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41)
2015-08-24 19:29:31,255 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,256 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.invocationmetrics.WaitTimeInterceptor.processInvocation(WaitTimeInterceptor.java:43)
2015-08-24 19:29:31,256 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,256 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.security.SecurityContextInterceptor.processInvocation(SecurityContextInterceptor.java:95)
2015-08-24 19:29:31,257 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,257 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.interceptors.ShutDownInterceptorFactory$1.processInvocation(ShutDownInterceptorFactory.java:64)
2015-08-24 19:29:31,258 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,258 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:59)
2015-08-24 19:29:31,258 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,259 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50)
2015-08-24 19:29:31,260 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,260 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:55)
2015-08-24 19:29:31,261 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,262 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.component.messagedriven.MessageDrivenComponentDescription$5$1.processInvocation(MessageDrivenComponentDescription.java:211)
2015-08-24 19:29:31,262 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,263 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.ContextClassLoaderInterceptor.processInvocation(ContextClassLoaderInterceptor.java:64)
2015-08-24 19:29:31,263 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,264 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:326)
2015-08-24 19:29:31,264 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:448)
2015-08-24 19:29:31,264 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.AccessCheckingInterceptor.processInvocation(AccessCheckingInterceptor.java:61)
2015-08-24 19:29:31,265 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,265 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:326)
2015-08-24 19:29:31,266 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.PrivilegedWithCombinerInterceptor.processInvocation(PrivilegedWithCombinerInterceptor.java:80)
2015-08-24 19:29:31,266 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,266 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
2015-08-24 19:29:31,267 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:185)
2015-08-24 19:29:31,267 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:182)
2015-08-24 19:29:31,267 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
2015-08-24 19:29:31,268 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
2015-08-24 19:29:31,268 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ee.component.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:73)
2015-08-24 19:29:31,269 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at ejb.RegisterUserQueue$$$view107.onMessage(Unknown Source)
2015-08-24 19:29:31,269 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
2015-08-24 19:29:31,269 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
2015-08-24 19:29:31,270 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
2015-08-24 19:29:31,270 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at java.lang.reflect.Method.invoke(Method.java:483)
2015-08-24 19:29:31,270 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.inflow.MessageEndpointInvocationHandler.doInvoke(MessageEndpointInvocationHandler.java:139)
2015-08-24 19:29:31,271 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.jboss.as.ejb3.inflow.AbstractInvocationHandler.invoke(AbstractInvocationHandler.java:73)
2015-08-24 19:29:31,271 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at ejb.RegisterUserQueue$$$endpoint19.onMessage(Unknown Source)
2015-08-24 19:29:31,272 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.hornetq.ra.inflow.HornetQMessageHandler.onMessage(HornetQMessageHandler.java:321)
2015-08-24 19:29:31,272 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.hornetq.core.client.impl.ClientConsumerImpl.callOnMessage(ClientConsumerImpl.java:1116)
2015-08-24 19:29:31,272 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.hornetq.core.client.impl.ClientConsumerImpl.access$500(ClientConsumerImpl.java:56)
2015-08-24 19:29:31,273 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.hornetq.core.client.impl.ClientConsumerImpl$Runner.run(ClientConsumerImpl.java:1251)
2015-08-24 19:29:31,273 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at org.hornetq.utils.OrderedExecutorFactory$OrderedExecutor$1.run(OrderedExecutorFactory.java:104)
2015-08-24 19:29:31,273 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
2015-08-24 19:29:31,274 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
2015-08-24 19:29:31,274 ERROR [stderr] (Thread-357 (HornetQ-client-global-threads-934440401)) at java.lang.Thread.run(Thread.java:745)
P.S。我在这里选择了Eager，因为我假设一个用户不会有太多的令牌，我可能会改为Lazy，但我还有其他字段会被Lazily加载，所以这与这个问题无关。
P.P.S我知道用户已被插入，因为我有一行在tkn.setUser(newuser)其他方法之前记录获得用户的用户名