Glassfish 应用程序没有使用 entityManager 注入服务类答案

【问题标题】：Glassfish application didn't inject service class with entityManagerGlassfish 应用程序没有使用 entityManager 注入服务类
【发布时间】：2014-08-12 15:53:48
【问题描述】：

我有一个使用 Maven 构建并具有以下模块结构的应用程序

<modules>
        <module>ProjectMonkeybutler-ear</module>
        <module>ProjectMonkeybutler-ejb</module>
        <module>ProjectMonkeybutler-web</module>
        <module>ProjectMonkeybutler-persistence</module>
 </modules>

我想@Inject 我的 BoothService 类，它有一个 EntityManager 来保存我的对象。 BoothService 类始终为 null，并且从不被应用程序服务器 (GF 4.0) 注入。

package com.skb.monkeybutler.persistence.service;

import com.skb.monkeybutler.persistence.entity.Booth;
import java.io.Serializable;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ejb.Stateless;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@Stateless
@Named("BoothService")
public class BoothService  implements Serializable {

    private static final Logger LOGGER = Logger.getLogger(BoothService.class.getName());

    @PersistenceContext
    protected EntityManager entityManager;

    public BoothService() {

        if(entityManager == null){
            LOGGER.info("EntityManger is null");
        }
    }

    protected EntityManager getEntityManager() {
       return entityManager;
    }

    public void persist(final Booth entity) {
        LOGGER.log(Level.INFO, "Persist {0}", entity);
        this.getEntityManager().persist(entity);
        LOGGER.log(Level.INFO, "Persisted");

    }

}

Web项目中我的Controller类：

package com.skb.monkeybutler.web;

import java.io.Serializable;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.enterprise.context.SessionScoped;
import javax.inject.Inject;
import javax.inject.Named;

@SessionScoped
@Named
public class CompanyRegistrationController implements Serializable {


    @Inject
    private @Named("BoothService") BoothService bs;

        public CompanyRegistrationController() {
            if(bs == null){ LOGGER.info("BoothService is null"); } 
    }
}

我的持久化xml：

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
  <persistence-unit name="com.skb_ProjectMonkeybutler-persistence_ejb_1.0-SNAPSHOTPU" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>jdbc/jeedb</jta-data-source>
    <class>com.skb.monkeybutler.persistence.entity.Companydata</class>
    <class>com.skb.monkeybutler.persistence.entity.CompanyEquipment</class>
    <class>com.skb.monkeybutler.persistence.entity.Studycourse</class>
    <class>com.skb.monkeybutler.persistence.entity.Booth</class>
    <class>com.skb.monkeybutler.persistence.entity.Setuptimeslot</class>
    <class>com.skb.monkeybutler.persistence.entity.Company</class>
    <class>com.skb.monkeybutler.persistence.entity.Volunteer</class>
    <class>com.skb.monkeybutler.persistence.entity.Servicepackage</class>
    <class>com.skb.monkeybutler.persistence.entity.Billingaddress</class>
    <class>com.skb.monkeybutler.persistence.entity.Equipment</class>
    <class>com.skb.monkeybutler.persistence.entity.Faculty</class>
    <class>com.skb.monkeybutler.persistence.entity.Team</class>
    <class>com.skb.monkeybutler.persistence.entity.Vacancy</class>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="javax.persistence.schema-generation.database.action" value="none"/>
      <property name="eclipselink.ddl-generation" value="none"/>
      <property name="eclipselink.logging.level" value="FINE"/>
      <property name="eclipselink.ddl-generation.output-mode" value="both"/>
      <!--  turn on fine logging: -->
      <property name="eclipselink.logging.level.sql" value="FINE"/>
      <property name="eclipselink.logging.parameters" value="true"/>
      <property name="eclipselink.logging.exceptions" value="true"/>
    </properties>
  </persistence-unit>
</persistence>

【问题讨论】：

标签： jakarta-ee jpa dependency-injection glassfish cdi

【解决方案1】：

从BoothService 类中创建一个接口。 CDI 只会从 EJB 注入接口（BoothService 是一个 EJB）

【讨论】：

【解决方案2】：

在构造函数中注入的字段将为空。它们是在创建对象后注入的。使用 @PostConstruct 注释定义方法并在那里测试注入的字段。
你也可以尝试用@EJB 注解注入BoothService。

【讨论】：