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EJB在服務中始終為空

[英]EJB always null in service

 原文  2016-06-17 21:19:35  9   1    java/ service/ jersey/ ejb

問題描述

我是服務方面的新秀，現在在向其注入EJB時發現一個問題，它始終為null。 我也曾在幾篇新舊文章中看到有這個問題的人，但是他們提出的解決方案要么行不通，要么我不知道如何實現。

我正在使用tomcat v7 + jersey實施v1.8。

到目前為止，我嘗試過的解決方案是：

  1. 使用spi注入，結果實例在那兒，但是我的EntityManager始終為null；

  2. 使服務成為@Stateless，總是也為null；

  3. 像這樣的帖子建議添加交易屬性，仍然為null；

  4. 最后一個我不知道如何實現， 這是在本文中 ，實現一個提供程序

我嘗試注入的Facade是我制造的： 

import javax.annotation.PostConstruct;
import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@LocalBean
@Stateless
public class AutoEntityFacade extends EntityFacade {

    @PersistenceContext(unitName = "myauto-unit")
    private EntityManager manager;

    @PostConstruct
    public void setup() {
        setEntityManager(manager);
    }

}

我的服務類也很簡單，但是注入不能正常工作： 

import br.com.aes.myauto.model.exception.HttpBusinessException;
import br.com.aes.myauto.model.person.Person;
import br.com.aes.myauto.service.facade.AutoEntityFacade;
import br.com.aes.myauto.service.facade.EntityFacade;
import br.com.aes.myauto.service.rest.CrudService;
import javax.ejb.EJB;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.ws.rs.Path;
import javax.ws.rs.QueryParam;
import org.apache.commons.lang3.StringUtils;

@Path("/person")
@Stateless
public class PersonService extends CrudService<Person> {

    @QueryParam(value = "name")
    private String name;
    @QueryParam(value = "lastName")
    private String lastName;
    @QueryParam(value = "email")
    private String email;

    @Override
    protected void setup() throws HttpBusinessException {
        if (StringUtils.isNotBlank(name)) {
            addParameter("name", "%" + name + "%");
        }
        if (StringUtils.isNotBlank(lastName)) {
            addParameter("lastName", "%" + lastName + "%");
        }
        if (StringUtils.isNotBlank(email)) {
            addParameter("email", "%" + email + "%");
        }
    }

    @Override
    protected String buildQuery() {
        return "select obj from Person obj " + getQuery();
    }

    @Override
    protected String buildCountQuery() {
        return "select count(obj) from Priority obj " + getQuery();
    }

    private String getQuery() {
        boolean firstClause = true;
        String result = "";
        String connector = "and";

        if (StringUtils.isNotBlank(name)) {
            if (firstClause) {
                result += "where ";
                firstClause = false;
            } else {
                result += connector;
            }
            result += " obj.name like :name ";
        }
        if (StringUtils.isNotBlank(lastName)) {
            if (firstClause) {
                result += "where ";
                firstClause = false;
            } else {
                result += connector;
            }
            result += " obj.lastName like :lastName ";
        }
        if (StringUtils.isNotBlank(email)) {
            if (firstClause) {
                result += "where ";
                firstClause = false;
            } else {
                result += connector;
            }
            result += " obj.email like :email ";
        }

        return result;
    }

    @PersistenceContext(unitName = "myauto-unit")
    private EntityManager manager;

    @EJB
    private AutoEntityFacade entityFacade;

    @Override
    protected EntityFacade getEntityFacade() {
        return entityFacade;
    }

    @Override
    public EntityManager getEntityManager() {
        return manager;
    }

}

有什么我想念的嗎？ 這是我的項目結構：

項目結構

如您所見，我還在Web和服務層上都提供了bean。 在我的服務中，我有一個測試類，因此我知道jersey正在正常工作並接受參數。

我在這里想念什么？

我更改了容器以查看是否可以有更詳細的異常，因為tomcat並沒有那么有用，這些都是結果，我仍然找不到。 

Warning: javax.ejb.EJBException: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB
    at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:454)
    at com.sun.ejb.containers.BaseContainer.getContext(BaseContainer.java:2547)
    at com.sun.ejb.containers.BaseContainer.preInvoke(BaseContainer.java:1899)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:89)
    at com.sun.proxy.$Proxy253.getBusinessObjectById(Unknown Source)
    at br.com.aes.myauto.service.crud.__EJB31_Generated__PersonService__Intf____Bean__.getBusinessObjectById(Unknown Source)
    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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:185)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:708)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:770)
    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$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:722)
Caused by: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB
    at com.sun.ejb.containers.StatelessSessionContainer$SessionContextFactory.create(StatelessSessionContainer.java:726)
    at com.sun.ejb.containers.util.pool.NonBlockingPool.getObject(NonBlockingPool.java:247)
    at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:449)
    ... 50 more
Caused by: javax.ejb.CreateException: Could not create stateless EJB
    at com.sun.ejb.containers.StatelessSessionContainer.createStatelessEJB(StatelessSessionContainer.java:534)
    at com.sun.ejb.containers.StatelessSessionContainer.access$000(StatelessSessionContainer.java:95)
    at com.sun.ejb.containers.StatelessSessionContainer$SessionContextFactory.create(StatelessSessionContainer.java:724)
    ... 52 more
Caused by: com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl$ComponentProcessorFactoryImpl.get(WebApplicationImpl.java:499)
    at com.sun.jersey.server.impl.ejb.EJBInjectionInterceptor.get(EJBInjectionInterceptor.java:104)
    at com.sun.jersey.server.impl.ejb.EJBInjectionInterceptor.init(EJBInjectionInterceptor.java:71)
    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 com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCallback(SystemInterceptorProxy.java:133)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.init(SystemInterceptorProxy.java:120)
    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 com.sun.ejb.containers.interceptors.CallbackInterceptor.intercept(InterceptorManager.java:964)
    at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:65)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:393)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:376)
    at com.sun.ejb.containers.StatelessSessionContainer.createStatelessEJB(StatelessSessionContainer.java:526)
    ... 54 more

Warning: StandardWrapperValve[MyAuto REST Service]: PWC1406: Servlet.service() for servlet MyAuto REST Service threw exception
com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl$ComponentProcessorFactoryImpl.get(WebApplicationImpl.java:499)
    at com.sun.jersey.server.impl.ejb.EJBInjectionInterceptor.get(EJBInjectionInterceptor.java:104)
    at com.sun.jersey.server.impl.ejb.EJBInjectionInterceptor.init(EJBInjectionInterceptor.java:71)
    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 com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCallback(SystemInterceptorProxy.java:133)
    at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.init(SystemInterceptorProxy.java:120)
    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 com.sun.ejb.containers.interceptors.CallbackInterceptor.intercept(InterceptorManager.java:964)
    at com.sun.ejb.containers.interceptors.CallbackChainImpl.invokeNext(CallbackChainImpl.java:65)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:393)
    at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:376)
    at com.sun.ejb.containers.StatelessSessionContainer.createStatelessEJB(StatelessSessionContainer.java:526)
    at com.sun.ejb.containers.StatelessSessionContainer.access$000(StatelessSessionContainer.java:95)
    at com.sun.ejb.containers.StatelessSessionContainer$SessionContextFactory.create(StatelessSessionContainer.java:724)
    at com.sun.ejb.containers.util.pool.NonBlockingPool.getObject(NonBlockingPool.java:247)
    at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:449)
    at com.sun.ejb.containers.BaseContainer.getContext(BaseContainer.java:2547)
    at com.sun.ejb.containers.BaseContainer.preInvoke(BaseContainer.java:1899)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
    at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:89)
    at com.sun.proxy.$Proxy253.getBusinessObjectById(Unknown Source)
    at br.com.aes.myauto.service.crud.__EJB31_Generated__PersonService__Intf____Bean__.getBusinessObjectById(Unknown Source)
    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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:185)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:708)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:770)
    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:722)

1 個解決方案

解決方案1
 0 已采納  2016-07-09 05:35:02

好吧，終於我找到了一種不錯的方法。

多數人可能知道我所做的工作方式（甚至我自己，也感到羞恥），但是由於這種情況，這似乎並不是最好的方法。

我重新創建了系統的某些部分，在這些部分中，我可以消除EJB並僅使用EntityManager，但這樣做之后，EJB或persistenceContext也不可行，因此我創建了一個新的entityManagerFactory，從而達到了目的。 

private EntityManager manager;
private EntityManagerFactory emf  = null;

public PersonService() {
    if (manager == null){
        emf = Persistence.createEntityManagerFactory("myauto-unit");
        manager = emf.createEntityManager();
    }
}

實現起來並不復雜，並且易於執行測試。

干杯

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