我正在尝试通过注释将无状态EJB注入我的JAX-RS Web服务.不幸的是,EJB是公正的null,NullPointerException当我尝试使用它时,我得到了它.
@Path("book")
public class BookResource {
@EJB
private BookEJB bookEJB;
public BookResource() {
}
@GET
@Produces("application/xml")
@Path("/{bookId}")
public Book getBookById(@PathParam("bookId") Integer id)
{
return bookEJB.findById(id);
}
}
我究竟做错了什么？
以下是有关我的机器的一些信息:
你们能展示一些有用的例子吗？
在我的Web应用程序中,我在Apache Tomcat(TomEE)/7.0.37服务器上使用OpenJPA.我使用Netbeans自动生成类("实体类来自数据库......"和"会话Bean来自实体类......").在SessionBean(例如UserFacade)我想获得EntityManager:
@Stateless
public class UserFacade extends AbstractFacade<User> {
@PersistenceContext(unitName = "CollDocPU")
private EntityManager em;
@Override
protected EntityManager getEntityManager() {
return em;
}
}
但是当我通过上面的方式得到它时,我得到了null.当我通过:
@Override
protected EntityManager getEntityManager() {
EntityManagerFactory emf = Persistence.createEntityManagerFactory("CollDocPU");
EntityManager ecm = emf.createEntityManager();
return ecm;
}
ecm不是null,没关系
我的persistence.xml:
<?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="CollDocPU" transaction-type="RESOURCE_LOCAL">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<class>model.entity.StudentAddSolution</class>
<class>model.entity.Lecturer</class>
<class>model.entity.Solution</class>
<class>model.entity.Student</class>
<class>model.entity.Course</class>
<class>model.entity.File</class>
<class>model.entity.CourseHasLecturer</class>
<class>model.entity.Mail</class>
<class>model.entity.StudentAtCourse</class>
<class>model.entity.Roles</class>
<class>model.entity.Task</class>
<class>model.entity.User</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:11080/myBase?zeroDateTimeBehavior=convertToNull"/>
<property name="javax.persistence.jdbc.password" value="pass,"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property …我在tomcat 7上使用Hibernate和Weld CDI运行一个项目.我已经编写了一个ServletContextListener来在应用程序启动期间创建EntityManagerFactory和EntityManager.
public class PersistenceListener implements ServletContextListener {
private static EntityManagerFactory entityManagerFactory;
public void contextInitialized(ServletContextEvent sce){
ServletContext context = sce.getServletContext();
entityManagerFactory = Persistence.createEntityManagerFactory("hibernate-test");
}
public void contextDestroyed(ServletContextEvent sce) {
entityManagerFactory.close();
}
public static EntityManager createEntityManager() {
if (entityManagerFactory == null) {
throw new IllegalStateException("Context is not initialized yet.");
}
return entityManagerFactory.createEntityManager();
}
}
我可以通过以下代码创建它,在我的测试类(它是一个arquillian测试类)中使用我的entityManager
EntityManager em = PersistenceListener.createEntityManager();
em.getTransaction().begin();
em.createQuery("delete from Game").executeUpdate();
em.getTransaction().commit();
这是我的测试类的完整代码
@RunWith(Arquillian.class)
public class HibernateTestSample {
@Deployment
public static WebArchive createTestArchive()
{
MavenDependencyResolver resolver = DependencyResolvers.use( …这是我的ApplicationContext.xml的代码提示
<context:spring-configured />
<context:annotation-config />
<context:component-scan base-package="com.apsas.jpa" />
<tx:annotation-driven />
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
<property name="persistenceUnitName" value="testjpa" />
</bean>
<bean id="entityManager"
class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
这是我的Dao实现
public class TeacherDaoImpl implements TeacherDao {
@Autowired
private EntityManager entityManager;
@Transactional
public Teacher addTeacher(Teacher teacher) {
entityManager.persist(teacher);
return teacher;
}
}
这是我的主班
public class TestApp {
public static void main(String[] args) {
ApplicationContext applicationContext = new ClassPathXmlApplicationContext(
"config/ApplicationContext.xml");
TeacherDao teacherDao = new TeacherDaoImpl();
Teacher teacher1 = teacherDao.addTeacher(new Teacher("First Teacher"));
}
} …
我正在尝试将我的项目与db连接.我有一个已经连接并在此数据库上运行的项目.我需要第二个并使用jms在它们之间进行通信.我配置secon连接到同一个数据库,它不工作.好的连接还可以.当我创建Entity类然后在db中我看到新表.很好.但我写的控制器应该注入实体管理器,它总是为空.我不知道为什么.这是我的配置.
@Configuration
@ComponentScan(basePackages = { "**.*****.**********" })
public class CalculationWorkerRootConfig {
@Bean
public static PropertyPlaceholderConfigurer propertyPlaceholderConfigurer() {
PropertyPlaceholderConfigurer ppc = new PropertyPlaceholderConfigurer();
ppc.setLocation(new ClassPathResource("/persistence.properties"));
return ppc;
}
}
这是经理配置器:
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories
public class CalculationWorkerPersistenceConfig implements TransactionManagementConfigurer {
@Value("${dataSource.driverClassName}")
private String driver;
@Value("${dataSource.url}")
private String url;
@Value("${dataSource.username}")
private String username;
@Value("${dataSource.password}")
private String password;
@Value("${hibernate.dialect}")
private String dialect;
@Value("${hibernate.hbm2ddl.auto}")
private String hbm2ddlAuto;
@Bean
public DataSource configureDataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(driver);
dataSource.setUrl(url);
dataSource.setUsername(username);
dataSource.setPassword(password);
return dataSource;
}
@Bean …