在我的项目中，我在持久层中使用JSF + JPA + CDI + WildFly 8.2。我有一个BasicDao，像这样：
public class BasicDao<M, K> {
private org.jboss.logging.Logger logger = org.jboss.logging.Logger
.getLogger("BasicDao");
@Inject
@Primary
protected EntityManager em;
Class<M> mclass;
public EntityManager getEm() {
return em;
}
public void setEm(EntityManager em) {
this.em = em;
}
@Transactional(value=TxType.NOT_SUPPORTED)
public M find(K id){
return em.find(mclass, id);
}
@Transactional(value=TxType.REQUIRED)
public void insert(M inst){
this.em.persist(inst);
}
@SuppressWarnings("unchecked")
@Transactional(value=TxType.REQUIRED)
public K insertWithAutoId(M inst){
this.em.persist(inst);
return (K) this.em.getEntityManagerFactory().getPersistenceUnitUtil().getIdentifier(inst);
}
@Transactional(value=TxType.REQUIRED)
public M update(M updated){
return this.em.merge(updated);
}
@Transactional(value=TxType.REQUIRED)
public void delete(M nonUsed){
this.em.remove(nonUsed);
}
}
和其他DAO一样：
@RequestScoped
public class UserDao extends BasicDao<User, Integer>{
@Transactional(value = TxType.NOT_SUPPORTED)
public User find(Integer id) {
return em.find(User.class, id);
}
@Transactional(value = TxType.REQUIRED)
public void insert(User inst) {
this.em.persist(inst);
}
@Transactional(value = TxType.REQUIRED)
public Integer insertWithAutoId(User inst) {
this.em.persist(inst);
return (Integer) this.em.getEntityManagerFactory()
.getPersistenceUnitUtil().getIdentifier(inst);
}
@Transactional(value = TxType.REQUIRED)
public User update(User updated) {
return this.em.merge(updated);
}
@Transactional(value = TxType.REQUIRED)
public void delete(User nonUsed) {
this.em.remove(nonUsed);
}
@SuppressWarnings("unchecked")
@Transactional(value = TxType.NOT_SUPPORTED)
public User findByName(String loginName) {
Query query = em.createQuery("select u from User u where u.loginName=:loginName");
List<User> users = (List<User>) query.setParameter("loginName",
loginName).getResultList();
return users.isEmpty() ? null : users.get(0);
}
}
在我的ManageredBean中，代码喜欢这个：
@Inject
private UserDao userDao;
但它经常引发异常，并非总是如此。我很困惑。像这样的异常堆栈：
09:50:59,945 FATAL [javax.enterprise.resource.webcontainer.jsf.context] (default task-27) JSF1073：在 RENDER_RESPONSE 6 的处理过程中捕捉到 com.sun.faces.mgbean.ManagedBeanCreationException：UIComponent-ClientId=，Message=对受管 bean resumeAudit 执行资源注入 (resource injection) 时发生错误
09:50:59,946 FATAL [javax.enterprise.resource.webcontainer.jsf.context] (default task-27) 对受管 bean resumeAudit 执行资源注入 (resource injection) 时发生错误: com.sun.faces.mgbean.ManagedBeanCreationException: 对受管 bean resumeAudit 执行资源注入 (resource injection) 时发生错误
at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:227) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:103) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:257) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:117) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:116) [javax.el-3.0.1-b05.jar:]
at com.sun.el.parser.AstValue.getBase(AstValue.java:151) [javax.el-3.0.1-b05.jar:]
at com.sun.el.parser.AstValue.getValue(AstValue.java:200) [javax.el-3.0.1-b05.jar:]
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:226) [javax.el-3.0.1-b05.jar:]
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.el.WeldValueExpression.getValue(WeldValueExpression.java:50) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109) [jsf-impl-2.2.8-jbossorg-1.jar:]
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIOutput.getValue(UIOutput.java:174) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.renderkit.html_basic.LabelRenderer.encodeBegin(LabelRenderer.java:120) [jsf-impl-2.2.8-jbossorg-1.jar:]
at javax.faces.component.UIComponentBase.encodeBegin(UIComponentBase.java:864) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:302) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.renderkit.html_basic.GridRenderer.renderRow(GridRenderer.java:185) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.renderkit.html_basic.GridRenderer.encodeChildren(GridRenderer.java:129) [jsf-impl-2.2.8-jbossorg-1.jar:]
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.render.Renderer.encodeChildren(Renderer.java:176) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1856) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1859) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:456) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133) [jsf-impl-2.2.8-jbossorg-1.jar:]
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) [jsf-impl-2.2.8-jbossorg-1.jar:]
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219) [jsf-impl-2.2.8-jbossorg-1.jar:]
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647) [jboss-jsf-api_2.2_spec-2.2.8.jar:2.2.8]
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:130) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at com.wangyin.hzcrp.auth.AuthFilter.doFilter(AuthFilter.java:109) [classes:]
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:132) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:85) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:61) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:56) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:63) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:58) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:70) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:76) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:261) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:247) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:76) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:166) [undertow-servlet-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:197) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:759) [undertow-core-1.1.0.Final.jar:1.1.0.Final]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_75]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_75]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_75]
Caused by: com.sun.faces.spi.InjectionProviderException: java.lang.IllegalStateException: JBAS011048: Failed to construct component instance
at org.jboss.as.jsf.injection.JSFInjectionProvider.invokePostConstruct(JSFInjectionProvider.java:63) [wildfly-jsf-injection-8.2.0.Final.jar:8.2.0.Final]
at com.sun.faces.mgbean.BeanBuilder.invokePostConstruct(BeanBuilder.java:221) [jsf-impl-2.2.8-jbossorg-1.jar:]
... 70 more
Caused by: java.lang.IllegalStateException: JBAS011048: Failed to construct component instance
at org.jboss.as.ee.component.BasicComponent.constructComponentInstance(BasicComponent.java:162)
at org.jboss.as.ee.component.BasicComponent.constructComponentInstance(BasicComponent.java:133)
at org.jboss.as.ee.component.BasicComponent.createInstance(BasicComponent.java:100)
at org.jboss.as.ee.component.ComponentRegistry$ComponentManagedReferenceFactory.getReference(ComponentRegistry.java:171)
at org.jboss.as.ee.component.ComponentRegistry.createInstance(ComponentRegistry.java:87)
at org.jboss.as.web.common.WebInjectionContainer.newInstance(WebInjectionContainer.java:77)
at org.jboss.as.jsf.injection.JSFInjectionProvider.invokePostConstruct(JSFInjectionProvider.java:61) [wildfly-jsf-injection-8.2.0.Final.jar:8.2.0.Final]
... 71 more
Caused by: org.jboss.weld.exceptions.WeldException: WELD-000049: Unable to invoke public void com.wangyin.hzcrp.controller.ResumeAudit.init() on com.wangyin.hzcrp.controller.ResumeAudit@628e5ac9
at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.invokeMethods(DefaultLifecycleCallbackInvoker.java:100) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.postConstruct(DefaultLifecycleCallbackInvoker.java:81) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.BasicInjectionTarget.postConstruct(BasicInjectionTarget.java:126) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.BeanInjectionTarget.postConstruct(BeanInjectionTarget.java:70) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.as.weld.deployment.processors.WeldComponentIntegrationProcessor$3.run(WeldComponentIntegrationProcessor.java:196) [wildfly-weld-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.as.weld.deployment.processors.WeldComponentIntegrationProcessor$AbstractInjectionTargetDelegatingInterceptor.processInvocation(WeldComponentIntegrationProcessor.java:260) [wildfly-weld-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.as.weld.injection.WeldInjectionInterceptor.processInvocation(WeldInjectionInterceptor.java:53) [wildfly-weld-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.as.ee.component.AroundConstructInterceptorFactory$1.processInvocation(AroundConstructInterceptorFactory.java:28)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.as.weld.injection.WeldInterceptorInjectionInterceptor.processInvocation(WeldInterceptorInjectionInterceptor.java:56) [wildfly-weld-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.as.weld.injection.WeldInjectionContextInterceptor.processInvocation(WeldInjectionContextInterceptor.java:43) [wildfly-weld-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.as.ee.concurrent.ConcurrentContextInterceptor.processInvocation(ConcurrentContextInterceptor.java:45) [wildfly-ee-8.2.0.Final.jar:8.2.0.Final]
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.invocation.ContextClassLoaderInterceptor.processInvocation(ContextClassLoaderInterceptor.java:64)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:326)
at org.jboss.invocation.PrivilegedWithCombinerInterceptor.processInvocation(PrivilegedWithCombinerInterceptor.java:80)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:61)
at org.jboss.as.ee.component.BasicComponent.constructComponentInstance(BasicComponent.java:160)
... 77 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.7.0_75]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.7.0_75]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.7.0_75]
at java.lang.reflect.Method.invoke(Method.java:606) [rt.jar:1.7.0_75]
at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.invokeMethods(DefaultLifecycleCallbackInvoker.java:98) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
... 100 more
Caused by: java.lang.IllegalArgumentException: Can not set javax.persistence.EntityManager field com.wangyin.hzcrp.storage.dao.BasicDao.em to com.wangyin.hzcrp.storage.dao.ResumeDao$Proxy$_$$_WeldSubclass
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:164) [rt.jar:1.7.0_75]
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:168) [rt.jar:1.7.0_75]
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:55) [rt.jar:1.7.0_75]
at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:75) [rt.jar:1.7.0_75]
at java.lang.reflect.Field.set(Field.java:741) [rt.jar:1.7.0_75]
at org.jboss.weld.injection.FieldInjectionPoint.inject(FieldInjectionPoint.java:94) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.util.Beans.injectBoundFields(Beans.java:370) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.util.Beans.injectFieldsAndInitializers(Beans.java:381) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.ResourceInjector$1.proceed(ResourceInjector.java:70) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.InjectionContextImpl.run(InjectionContextImpl.java:48) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.ResourceInjector.inject(ResourceInjector.java:72) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.injection.producer.BasicInjectionTarget.inject(BasicInjectionTarget.java:121) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.bean.ManagedBean.create(ManagedBean.java:150) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.context.AbstractContext.get(AbstractContext.java:96) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.bean.proxy.ContextBeanInstance.getInstance(ContextBeanInstance.java:98) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:78) [weld-core-impl-2.2.6.Final.jar:2014-10-03 10:05]
at com.wangyin.hzcrp.storage.dao.ResumeDao$Proxy$_$$_WeldClientProxy.find(Unknown Source) [crp-storage-1.0.0-SNAPSHOT.jar:]
at com.wangyin.hzcrp.controller.ResumeAudit.init(ResumeAudit.java:81) [classes:]
... 105 more
有人能帮助我吗？万分感谢。
答案 0 :(得分：19)
将持久化上下文注入托管Bean的适当方法如下：
@PersistenceContext(unitName = "my-pu-name")
private EntityManager em;
请注意，这只能在托管bean上完成，即由容器创建/销毁的bean。
最佳做法是将其添加为生产者，以便您可以在托管bean中使用@Inject：
@ApplicationScoped
public class ApplicationResources {
@Produces
@PersistenceContext(unitName = "my-pu-name")
private EntityManager em;
}
然后，您可以将其注入JAX-RS端点，EJB和容器管理的任何其他bean：
@Stateless
public class FooService {
@Inject
EntityManager em;
}