无法在persistence.xml文件中调用JNDI资源

Question

虽然看起来很多用户都面临同样的问题，但我必须发布自己的问题，考虑到现在，没有任何来自已有人的建议对我有用。或者我错过了什么？

这里是我的persistence.xml文件（位于纳resources/META-INF/目录，在Maven项目）：

<?xml version="1.0" encoding="UTF-8"?> 
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd "> 
    <persistence-unit name="brass-unit" transaction-type="RESOURCE_LOCAL"> 
     <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> 
    <properties> 
       <property name="hibernate.connection.datasource" value="java:/comp/env/jdbc/BrassDB"/> 
    </properties> 
</persistence-unit> 

resources/META-INF下，我也有context.xml文件：

<?xml version="1.0" encoding="UTF-8"?> 
<Context> 
    <Resource name="jdbc/BrassDB" auth="Container" type="javax.sql.DataSource" 
       driverClassName="org.postgresql.Driver" 
       url="jdbc:postgresql://localhost:5432/mydb" username="usr" password="pwd" 
       maxActive="20" maxIdle="10" maxWait="-1"/> 
</Context> 

在web.xml文件我有：

在web.xml中

<?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> 
<display-name>brass_directory_business</display-name> 
<welcome-file-list> 
    <welcome-file>index.html</welcome-file> 
    <welcome-file>index.htm</welcome-file> 
    <welcome-file>index.jsp</welcome-file> 
    <welcome-file>default.html</welcome-file> 
    <welcome-file>default.htm</welcome-file> 
    <welcome-file>default.jsp</welcome-file> 
</welcome-file-list> 
<resource-ref> 
    <description>db connection</description> 
    <res-ref-name>jdbc/BrassDB</res-ref-name> 
    <res-type>javax.sql.DataSource</res-type> 
    <res-auth>Container</res-auth> 
</resource-ref> 

注：有时我评论resource-ref标签，但相同的行为结果。

现在，在我的servlet，当我运行它，一切正常：

InitialContext ctx = null; 
try { 
    ctx = new InitialContext(); 
    if (ctx == null) { 
     throw new Exception("no context!"); 
    } 
    DataSource ds = (DataSource)ctx.lookup("java:/comp/env/jdbc/BrassDB"); 
    if (ds == null) { 
     throw new Exception("data source not found!"); 
    } 
    Connection conn = ds.getConnection(); 
    ResultSet rs = conn.createStatement().executeQuery("SELECT * FROM person"); 
    int n = 0; 
    while (rs.next()) { 
     n++; 
    } 
    System.out.println("rs length is: " + n); 
} catch (Exception e) { 
    e.printStackTrace(); 
} 

但是当我运行此：

EntityManagerFactory emf = Persistence.createEntityManagerFactory("brass-unit"); 
EntityManager em = emf.createEntityManager();  
em.createNamedQuery("Person.findAll", Person.class).getResultList(); 

我得到这个异常：

Mar 04, 2014 4:48:56 PM org.apache.catalina.core.StandardWrapperValve invoke 
SEVERE: Servlet.service() for servlet [com.banco.Test] in context with path [/brass_directory_business] threw exception 
javax.persistence.PersistenceException: Unable to build entity manager factory 
    at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:81) 
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54) 
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55) 
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39) 
    at com.banco.Test.doPost(Test.java:34) 
    at com.banco.Test.doGet(Test.java:27) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:620) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) 
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) 
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) 
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) 
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at java.lang.Thread.run(Thread.java:744) 
Caused by: org.hibernate.engine.jndi.JndiException: Unable to lookup JNDI name [java:/comp/env/jdbc/BrassDB] 
    at org.hibernate.engine.jndi.internal.JndiServiceImpl.locate(JndiServiceImpl.java:117) 
    at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.configure(DatasourceConnectionProviderImpl.java:115) 
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:89) 
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:206) 
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:178) 
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:260) 
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:94) 
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:89) 
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:206) 
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:178) 
    at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885) 
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843) 
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:850) 
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843) 
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:399) 
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842) 
    at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:73) 
    ... 26 more 
Caused by: javax.naming.NameNotFoundException: Name [java:/comp/env/jdbc/BrassDB] is not bound in this Context. Unable to find [java:]. 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:819) 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:153) 
    at javax.naming.InitialContext.lookup(InitialContext.java:415) 
    at org.hibernate.engine.jndi.internal.JndiServiceImpl.locate(JndiServiceImpl.java:114) 
    ... 42 more 

我的pom.xml的样子：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 
    //...... 
    <dependencies> 
     <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate-core</artifactId> 
      <version>4.3.1.Final</version> 
     </dependency> 
     <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate-entitymanager</artifactId> 
      <version>4.3.1.Final</version> 
     </dependency> 
     //... 
    </dependencies> 
    <build> 
     <plugins> 
      <plugin> 
     //... 
      </plugin> 
     </plugins> 
    </build> 
</project> 

我使用tomcat 7.0.52作为服务器。 有没有人有任何建议如何解决我的问题？

Answer 1

对我来说，这似乎是一个休眠问题。我只是将hibernate版本更改为4.2.7，并且运行良好。

Answer 2

我有另一个想法：

1.增加<exclude-unlisted-classes>false</exclude-unlisted-classes>您的persistence.xml，<persistence-unit> elemet

2.添加以下到您的persistence.xml，<persistence-unit>/<properties>元素：

<property name="javax.persistence.jdbc.driver" value="org.hsqldb.jdbcDriver"/> 
<property name="javax.persistence.jdbc.url" value="jdbc:hsqldb:mem:standalone"/> 
<property name="javax.persistence.jdbc.user" value="sa"/> 
<property name="javax.persistence.jdbc.password" value=""/> 

此外，请尝试从您的pom.xml中删除hibernate-core依赖项。

现在你应该可以使用entitymanager。如果您需要JDBC连接，只需从EntityManager实例中获取它（而不是通过JNDI获取它的方式）。