实体经理不要被Guice注入

Question

>我更新了我的createInjector调用以包含我的JPAPersisteModule...

Guice.createInjector(new ApplicationModule(), new JpaPersistModule("simpleRestApplication"));

在我的服务上，我的 DAO 被毫无问题地注入了......

@Path("/users")
public class UserService {
@Inject
private UserDAO dao;
public UserService() {
Application.getInjector().injectMembers(this);
}

}

在我的用户DAOImpl上，提供者不会被注入...

@Inject
private Provider<EntityManager> em;

这将打印到控制台上：

1) Error in custom provider, java.lang.NullPointerException while locating com.google.inject.persist.jpa.JpaPersistService while locating javax.persistence.EntityManager

在我的persistence.xml上，持久性单元声明如下：

<persistence-unit name="simpleRestApplication">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<properties>
<!-- Configuração do driver -->
<property name="hibernate.dialect"
value="org.hibernate.dialect.Oracle10gDialect" />
<property name="hibernate.connection.driver_class"
value="oracle.jdbc.driver.OracleDriver" />
<!-- Configuração de conexão -->
<property name="hibernate.connection.url"
value="jdbc:oracle:thin:@localhost:1521/XE" />
<property name="hibernate.connection.username"
value="system" />
<property name="hibernate.connection.password"
value="myPassword123" />
<property name="hibernate.connection.autocommit"
value="true" />
<!-- Configuração do hibernate -->
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.format_sql" value="true" />
<property name="hibernate.hbm2ddl.auto" value="update" />
<property name="hibernate.connection.release_mode"
value="auto" />
<property name="current_session_context_class"
value="thread" />
<property name="hibernate.connection.autoReconnect"
value="true" />
</properties>
</persistence-unit>

Answer 1

基于此链接，我更改了ApplicationModule上的configure()方法以安装JpaPersistenceModule并启动PersistService...

@Singleton
private static class JPAInitializer {
@Inject
public JPAInitializer(final PersistService service) {
service.start();
}
}
@Override
protected void configure() {
install(new JpaPersistModule("simpleRestApplication"));
bind(JPAInitializer.class).asEagerSingleton();
// another bindings...
}

现在实体管理器被注入了，没有任何错误...

public class UserDAOImpl implements UserDAO {
@Inject
private EntityManager em;
}