没有使用@PersistenceUnit注入EntityManagerFactory [英] EntityManagerFactory not being injected using @PersistenceUnit
问题描述
我是Java初学者.我在使用JTA事务配置持久性单元时遇到麻烦.
我需要使用已经定义，配置和填充的PostgreSQL数据库.使用netbeans，我创建了persistance.xml和glassfish-resources.xml作为休假:
I'm a java beginner. I'm in trouble to configure a persistance unit using JTA transactions.
I need to use a PostgreSQL database that is already defined, configured and populated. Using netbeans, i created the persistance.xml and glassfish-resources.xml as fallows:
<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="WellWatcherPU" transaction-type="JTA">
<jta-data-source>WellWatcherDB</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="eclipselink.logging.logger" value="org.eclipse.persistence.logging.DefaultSessionLog"/>
<property name="eclipselink.logging.level" value="FINE"/>
</properties>
</persistence-unit>
</persistence>
和
<resources>
<jdbc-connection-pool allow-non-component-callers="false" associate-with-thread="false" connection-creation-retry-attempts="0" connection-creation-retry-interval-in-seconds="10" connection-leak-reclaim="false" connection-leak-timeout-in-seconds="0" connection-validation-method="auto-commit" datasource-classname="org.postgresql.ds.PGSimpleDataSource" fail-all-connections="false" idle-timeout-in-seconds="300" is-connection-validation-required="false" is-isolation-level-guaranteed="true" lazy-connection-association="false" lazy-connection-enlistment="false" match-connections="false" max-connection-usage-count="0" max-pool-size="32" max-wait-time-in-millis="60000" name="post-gre-sql_geowellex_geowellexPool" non-transactional-connections="false" pool-resize-quantity="2" res-type="javax.sql.DataSource" statement-timeout-in-seconds="-1" steady-pool-size="8" validate-atmost-once-period-in-seconds="0" wrap-jdbc-objects="false">
<property name="serverName" value="localhost"/>
<property name="portNumber" value="5432"/>
<property name="databaseName" value="DBNAME"/>
<property name="User" value="USER"/>
<property name="Password" value="PASSWORD"/>
<property name="URL" value="jdbc:postgresql://localhost:5432/DBNAME"/>
<property name="driverClass" value="org.postgresql.Driver"/>
</jdbc-connection-pool>
<jdbc-resource enabled="true" jndi-name="WellWatcherDB" object-type="user" pool-name="post-gre-sql_geowellex_geowellexPool"/>
</resources>
这就是我获取EntityManagerFactory和EntityManager的方式(如在netBeans示例中使用的那样)
And this is how i get the EntityManagerFactory and EntityManager (as used in the netBeans example)
public class EUserDao {
@Resource
private UserTransaction utx = null;
@PersistenceUnit(unitName = "WellWatcherPU")
private EntityManagerFactory emf = null;
public EntityManager getEntityManager() {
return emf.createEntityManager(); <-------- NullPointerException here
}
public EUser getOne(long userId){
EntityManager em = getEntityManager();
try {
return em.find(EUser.class, userId);
} finally {
em.close();
}
}
这是我的glassfish部署日志:
And here is my glassfish deploy log:
信息:[EL配置]:2012-05-10 12:01:13.534--ServerSession(2017352940)-连接(1901223982)-线程(Thread [admin-thread-pool-4848(5)，5 ，grizzly-kernel])-连接(DatabaseLogin( platform =>数据库平台 用户名=>" connector => JNDIConnector数据源名称=> null ))
Informações: [EL Config]: 2012-05-10 12:01:13.534--ServerSession(2017352940)--Connection(1901223982)--Thread(Thread[admin-thread-pool-4848(5),5,grizzly-kernel])--connecting(DatabaseLogin( platform=>DatabasePlatform user name=> "" connector=>JNDIConnector datasource name=>null ))
信息:[EL配置]:2012-05-10 12:01:13.534--ServerSession(2017352940)-连接(1462281761)-线程(Thread [admin-thread-pool-4848(5)，5 ，grizzly-kernel])-已连接:jdbc:postgresql://localhost:5432/geowellex?loginTimeout = 0& prepareThreshold = 0 用户:geowellex 数据库:PostgreSQL版本:9.1.3 驱动程序:PostgreSQL本机驱动程序版本:带SSL的PostgreSQL 8.3 JDBC3(内部版本603)
Informações: [EL Config]: 2012-05-10 12:01:13.534--ServerSession(2017352940)--Connection(1462281761)--Thread(Thread[admin-thread-pool-4848(5),5,grizzly-kernel])--Connected: jdbc:postgresql://localhost:5432/geowellex?loginTimeout=0&prepareThreshold=0 User: geowellex Database: PostgreSQL Version: 9.1.3 Driver: PostgreSQL Native Driver Version: PostgreSQL 8.3 JDBC3 with SSL (build 603)
信息:[EL配置]:2012-05-10 12:01:13.534--ServerSession(2017352940)-连接(766700859)-线程(Thread [admin-thread-pool-4848(5)，5 ，grizzly-kernel])-连接(DatabaseLogin( platform => PostgreSQL平台 用户名=>" connector => JNDIConnector数据源名称=> null ))
Informações: [EL Config]: 2012-05-10 12:01:13.534--ServerSession(2017352940)--Connection(766700859)--Thread(Thread[admin-thread-pool-4848(5),5,grizzly-kernel])--connecting(DatabaseLogin( platform=>PostgreSQLPlatform user name=> "" connector=>JNDIConnector datasource name=>null ))
怎么了?
推荐答案
最可能的问题是您的EUserDao只是常规类.注入仅适用于容器管理的类.对于普通类，不会处理诸如@PersistenceUnit和@Resource之类的注释.
Most likely problem is that your EUserDao is just regular class. Injection works only for container managed classes. Annotations like @PersistenceUnit and @Resource are not processed for normal classes.
以下类的类型是容器管理的类(在那些@PersistenceUnit中可以使用):
Following types of classes are container managed classes (and in those @PersistenceUnit can be used):
- Servlet:Servlet，Servlet过滤器，事件监听器
- JSP:标记处理程序，标记库事件侦听器
- JSF:范围内的受管bean
- JAX-WS:服务端点，处理程序
- EJB:bean，拦截器
- 托管豆:托管豆
- CDI:CDI风格的托管bean，装饰器
- Java EE平台:主类(静态)，登录回调处理程序
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