在带有Wildfly的Jersey上使用@PersistenceUnit注入EntityManagerFactory [英] Inject EntityManagerFactory using @PersistenceUnit on Jersey with Wildfly

问题描述

我正在尝试使用@PersistenceUnit注入EntityManagerFactory，但它始终为null.

I'm trying to inject EntityManagerFactory using @PersistenceUnit, but it's always null.

我认为我的persistence.xml可以，因为我可以使用以下代码获取EntityManager:

I think my persistence.xml is OK, since I can get the EntityManager with this code:

EntityManager em = Persistence.createEntityManagerFactory("myPersistenceUnit").createEntityManager();

因此，我想知道我是否做错了什么，或者在使用Jersey(2.23)和Wildfly 10(JBoss EAP 7)时是否无法做到这一点.

So, I would like to know if I'm doing something wrong, or if this is not possible when using Jersey (2.23) and Wildfly 10 (JBoss EAP 7).

这是我到目前为止所做的:

Here is what I've done so far:

• 在eclipse上创建了Jersey-quickstart-webapp maven项目；

• 向我的pom.xml添加了以下依赖项:

• Created a jersey-quickstart-webapp maven project on eclipse;

• Added the following dependencies to my pom.xml:

<dependency>
  <groupId>javax</groupId>
  <artifactId>javaee-api</artifactId>
  <version>7.0</version>
</dependency>
<dependency>
  <groupId>org.hibernate.javax.persistence</groupId>
  <artifactId>hibernate-jpa-2.1-api</artifactId>
  <version>1.0.0.Final</version>
</dependency>
<dependency>
  <groupId>org.hibernate</groupId>
  <artifactId>hibernate-entitymanager</artifactId>
  <version>5.2.2.Final</version>
</dependency>
<dependency>
  <groupId>com.hynnet</groupId>
  <artifactId>oracle-driver-ojdbc6</artifactId>
  <version>12.1.0.1</version>
</dependency>

创建了persistence.xml:

Created the persistence.xml:

<persistence-unit name="myPersistenceUnit"
  transaction-type="RESOURCE_LOCAL">
  <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
  <!-- All persistence classes must be listed -->
  <class>com.mps.classes.TermosPesquisados</class>
  <properties>
    <!-- Provider-specific connection properties -->
    <property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver" />
    <property name="javax.persistence.jdbc.url" value="JDBC_URL" />
    <property name="javax.persistence.jdbc.user" value="USER" />
    <property name="javax.persistence.jdbc.password" value="PASSWORD" />
    <property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
    <property name="hibernate.show_sql" value="false" />
    <property name="hibernate.connection.release_mode" value="after_transaction" />
    <property name="hibernate.connection.isolation" value="2" />
  </properties>
</persistence-unit>

修改了MyResource.java:

Modified the MyResource.java:

@ManagedBean
@Path("myresource")
public class MyResource {

  @PersistenceUnit(unitName= "myPersistenceUnit")
  private EntityManagerFactory emf;

  @GET
  @Produces(MediaType.TEXT_PLAIN)
  public String getIt() {
    if(emf == null)
      return "emf is null";
    return "emf is not null";
  }
}

添加了一个空的beans.xml(不确定是否有必要)；

Added an empty beans.xml (not sure if it's necessary);

推荐答案

泽西岛似乎与Resteasy发生冲突.这样，我有2个选择:

It seems that Jersey conflicts with Resteasy. This way, I had 2 options:

• 在JBoss/Wildfly上关闭Resteasy(我知道这是可能的，但是我不知道如何)；
• 删除球衣并改用Resteasy；

我最终选择了第二个选项，因为它比较容易，而且我没有理由专门使用球衣.

I ended up choosing the 2nd option because it was easier and I have no reasons to use specifically Jersey.

这样，我不得不更改我的web.xml，替换为:

This way, I had to change my web.xml, replacing this:

<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
...
<servlet-mapping>
  <servlet-name>Jersey Web Application</servlet-name>
  <url-pattern>/webapi/*</url-pattern>
</servlet-mapping>

为此:

<servlet-name>javax.ws.rs.core.Application</servlet-name>
...
<servlet-mapping>
  <servlet-name>javax.ws.rs.core.Application</servlet-name>
  <url-pattern>/webapi/*</url-pattern>
</servlet-mapping>

*另一个选择是创建一个扩展Application类的类.

*Another option was to create a class extending Application class.

* beans.xml不是必需的.

*beans.xml was not necessary.

然后，我用@Stateless注释了资源类，并且能够正确注入EntityManager:

Then, I annotated my resource class with @Stateless and I was able to inject EntityManager properly:

@Path("myresource")
@Stateless
public class MyResource {

  @PersistenceContext(unitName="myPersistenceUnit")
  private EntityManager em; 
...

在这一点上，EntityManager还可以，但是不知何故它正在使用JBoss h2内存数据库(ExampleDS). 因此，我在JBoss(OracleDS)上配置了一个oracle数据源，并更新了persistence.xml以使用OracleDS和JTA而不是"RESOURCE_LOCAL":

At this point, EntityManager was OK, but somehow it was using JBoss h2 in-memmory database (ExampleDS). So, I configured an oracle datasource on JBoss (OracleDS) and updated my persistence.xml to use OracleDS and JTA instead of "RESOURCE_LOCAL":

<persistence-unit name="myPersistenceUnit" transaction-type="JTA">
  <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
  <jta-data-source>java:jboss/datasources/OracleDS</jta-data-source>
...

通过这些步骤，我能够注入EntityManager并成功进行CRUD操作.

With those steps I was able to inject EntityManager and make my CRUD operations successfully.

这篇关于在带有Wildfly的Jersey上使用@PersistenceUnit注入EntityManagerFactory的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！