登录
当前位置： 首页 > 知识库问答 >
问题：

在大多数基本示例中，无法使用@PersistenceContext注入EntityManager

容俊豪
2023-03-14

为了使用实体管理器的PersistenceContext注入来测试JPA，我有一个基本的示例项目，其结构如下：Person entity：

@Entity
public class Person {

    @Id
    @GeneratedValue
    private long id;
    private String name;
    private String surname;

    public Person() {
    }

    public Person(String name, String surname) {
        this.name = name;
        this.surname = surname;
    }

    public long getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        if (id != person.id) return false;
        if (name != null ? !name.equals(person.name) : person.name != null) return false;
        return surname != null ? surname.equals(person.surname) : person.surname == null;
    }

    @Override
    public int hashCode() {
        int result = (int) (id ^ (id >>> 32));
        result = 31 * result + (name != null ? name.hashCode() : 0);
        result = 31 * result + (surname != null ? surname.hashCode() : 0);
        return result;
    }

    @Override
    public String toString() {
        return "Person{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", surname='" + surname + '\'' +
                '}';
    }
}

Rest配置：

@ApplicationPath("/api")
public class RestConfig extends Application {
}

测试restendpoint：

@Path("/test")
//@Vetoed
public class TestResource {

    @PersistenceContext(unitName = "pu")
    private EntityManager entityManager;

    @GET
    @Path("/dbtest")
    public Response testDb() {
        System.out.println("DBG Invocation of dbtest");
        Person person=new Person("tomas","bisciak");
        entityManager.persist(person); //ALWAYS NULL
        System.out.println("Persisted");
        Person retrievedEntity= entityManager.find(Person.class,1);
        System.out.println("Retrieved entity:"+retrievedEntity);
        return Response.status(Response.Status.OK).build();
    }

}

persistence.xml

<persistence 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"
             version="2.1">

    <persistence-unit name="pu" transaction-type="JTA">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <jta-data-source>java:jboss/datasources/MySqlDS2</jta-data-source>

        <class>Person</class>

        <properties>

            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.user" value="root" />
            <property name="javax.persistence.jdbc.password" value="root" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/xchange" />

            <property name="eclipselink.logging.level" value="FINE"/>
            <property name="eclipselink.target-database" value="MySQL"/>
            <property name="eclipselink.ddl-generation" value="create-tables" />
        </properties>
    </persistence-unit>
</persistence>

在我的wildfly Standalone.xml中定义的数据源：

 <datasource jndi-name="java:jboss/datasources/MySqlDS2" pool-name="MySqlDS2" enabled="true" use-java-context="true">
                    <connection-url>jdbc:mysql://localhost:3306/xchange</connection-url>
                    <driver-class>com.mysql.jdbc.Driver</driver-class>
                    <driver>mysql-connector-java-5.1.45-bin.jar_com.mysql.jdbc.Driver_5_1</driver>
                    <security>
                        <user-name>root</user-name>
                        <password>root</password>
                    </security>
                </datasource>

具有war结构的项目结构：

并在我的pom.xml中执行以下操作：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.bisciak.jpa</groupId>
    <artifactId>jpatest</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>


    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
        <java.version>1.8</java.version>

        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>

        <failOnMissingWebXml>false</failOnMissingWebXml>
    </properties>


    <dependencies>

        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
        </dependency>



        <!-- https://mvnrepository.com/artifact/org.eclipse.persistence/eclipselink -->
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>eclipselink</artifactId>
            <version>2.7.1</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>6.0.6</version>
        </dependency>

        <!--Testing dependencies-->

        <!-- https://mvnrepository.com/artifact/org.mockito/mockito-core -->
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>2.13.0</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

    </dependencies>


</project>

所有这些都运行在最新的稳定的Wildfly上，我得到的输出是：

Connected to server
[2018-01-29 03:17:37,085] Artifact jpatest:war exploded: Artifact is being deployed, please wait...
15:17:37,168 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-2) WFLYSRV0027: Starting deployment of "jpatest-1.0-SNAPSHOT" (runtime-name: "jpatest-1.0-SNAPSHOT.war")
15:17:38,312 INFO  [org.jboss.weld.deployer] (MSC service thread 1-5) WFLYWELD0003: Processing weld deployment jpatest-1.0-SNAPSHOT.war
15:17:38,351 INFO  [org.hibernate.validator.internal.util.Version] (MSC service thread 1-5) HV000001: Hibernate Validator 5.3.5.Final
15:17:38,516 INFO  [org.jboss.as.connector.deployers.jdbc] (MSC service thread 1-5) WFLYJCA0005: Deploying non-JDBC-compliant driver class com.mysql.cj.jdbc.Driver (version 6.0)
15:17:38,537 INFO  [org.jboss.weld.Version] (MSC service thread 1-5) WELD-000900: 2.4.3 (Final)
15:17:38,574 INFO  [org.jboss.as.connector.deployers.jdbc] (MSC service thread 1-1) WFLYJCA0018: Started Driver service with driver-name = jpatest-1.0-SNAPSHOT.war_com.mysql.cj.jdbc.Driver_6_0
15:17:38,896 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-6) MSC000001: Failed to start service jboss.deployment.unit."jpatest-1.0-SNAPSHOT.war".WeldStartService: org.jboss.msc.service.StartException in service jboss.deployment.unit."jpatest-1.0-SNAPSHOT.war".WeldStartService: Failed to start service
    at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1978)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: WFLYWELD0037: Error injecting persistence unit into CDI managed bean. Can't find a persistence unit named 'pu' in deployment jpatest-1.0-SNAPSHOT.war for injection point private javax.persistence.EntityManager TestResource.entityManager
    at org.jboss.as.weld.services.bootstrap.WeldJpaInjectionServices.getScopedPUName(WeldJpaInjectionServices.java:114)
    at org.jboss.as.weld.services.bootstrap.WeldJpaInjectionServices.registerPersistenceContextInjectionPoint(WeldJpaInjectionServices.java:77)
    at org.jboss.weld.injection.ResourceInjectionFactory$PersistenceContextResourceInjectionProcessor.getResourceReferenceFactory(ResourceInjectionFactory.java:350)
    at org.jboss.weld.injection.ResourceInjectionFactory$PersistenceContextResourceInjectionProcessor.getResourceReferenceFactory(ResourceInjectionFactory.java:338)
    at org.jboss.weld.injection.ResourceInjectionFactory$ResourceInjectionProcessor.createFieldResourceInjection(ResourceInjectionFactory.java:216)
    at org.jboss.weld.injection.ResourceInjectionFactory$ResourceInjectionProcessor.createResourceInjections(ResourceInjectionFactory.java:188)
    at org.jboss.weld.injection.ResourceInjectionFactory.discoverType(ResourceInjectionFactory.java:448)
    at org.jboss.weld.injection.ResourceInjectionFactory.getResourceInjections(ResourceInjectionFactory.java:96)
    at org.jboss.weld.injection.producer.ResourceInjector.<init>(ResourceInjector.java:59)
    at org.jboss.weld.injection.producer.ResourceInjector.of(ResourceInjector.java:49)
    at org.jboss.weld.injection.producer.BeanInjectionTarget.<init>(BeanInjectionTarget.java:63)
    at org.jboss.weld.injection.producer.BeanInjectionTarget.createDefault(BeanInjectionTarget.java:47)
    at org.jboss.weld.manager.InjectionTargetFactoryImpl.chooseInjectionTarget(InjectionTargetFactoryImpl.java:113)
    at org.jboss.weld.manager.InjectionTargetFactoryImpl.createInjectionTarget(InjectionTargetFactoryImpl.java:86)
    at org.jboss.weld.bean.ManagedBean.<init>(ManagedBean.java:100)
    at org.jboss.weld.bean.ManagedBean.of(ManagedBean.java:80)
    at org.jboss.weld.bootstrap.AbstractBeanDeployer.createManagedBean(AbstractBeanDeployer.java:261)
    at org.jboss.weld.bootstrap.BeanDeployer.createClassBean(BeanDeployer.java:226)
    at org.jboss.weld.bootstrap.ConcurrentBeanDeployer$2.doWork(ConcurrentBeanDeployer.java:74)
    at org.jboss.weld.bootstrap.ConcurrentBeanDeployer$2.doWork(ConcurrentBeanDeployer.java:71)
    at org.jboss.weld.executor.IterativeWorkerTaskFactory$1.call(IterativeWorkerTaskFactory.java:62)
    at org.jboss.weld.executor.IterativeWorkerTaskFactory$1.call(IterativeWorkerTaskFactory.java:55)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    at org.jboss.threads.JBossThread.run(JBossThread.java:320)

15:17:38,896 ERROR [org.jboss.as.controller.management-operation] (management-handler-thread - 3) WFLYCTL0013: Operation ("deploy") failed - address: ([("deployment" => "jpatest-1.0-SNAPSHOT")]) - failure description: {"WFLYCTL0080: Failed services" => {"jboss.deployment.unit.\"jpatest-1.0-SNAPSHOT.war\".WeldStartService" => "Failed to start service
    Caused by: java.lang.IllegalArgumentException: WFLYWELD0037: Error injecting persistence unit into CDI managed bean. Can't find a persistence unit named 'pu' in deployment jpatest-1.0-SNAPSHOT.war for injection point private javax.persistence.EntityManager TestResource.entityManager"}}
15:17:38,911 ERROR [org.jboss.as.server] (management-handler-thread - 3) WFLYSRV0021: Deploy of deployment "jpatest-1.0-SNAPSHOT.war" was rolled back with the following failure message: 
{"WFLYCTL0080: Failed services" => {"jboss.deployment.unit.\"jpatest-1.0-SNAPSHOT.war\".WeldStartService" => "Failed to start service
    Caused by: java.lang.IllegalArgumentException: WFLYWELD0037: Error injecting persistence unit into CDI managed bean. Can't find a persistence unit named 'pu' in deployment jpatest-1.0-SNAPSHOT.war for injection point private javax.persistence.EntityManager TestResource.entityManager"}}
15:17:38,911 INFO  [org.jboss.as.connector.deployers.jdbc] (MSC service thread 1-8) WFLYJCA0019: Stopped Driver service with driver-name = jpatest-1.0-SNAPSHOT.war_com.mysql.cj.jdbc.Driver_6_0
15:17:38,963 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-6) WFLYSRV0028: Stopped deployment jpatest-1.0-SNAPSHOT (runtime-name: jpatest-1.0-SNAPSHOT.war) in 62ms
[2018-01-29 03:17:39,010] Artifact jpatest:war exploded: Error during artifact deployment. See server log for details.
[2018-01-29 03:17:39,010] Artifact jpatest:war exploded: java.lang.Exception: {"WFLYCTL0080: Failed services" => {"jboss.deployment.unit.\"jpatest-1.0-SNAPSHOT.war\".WeldStartService" => "Failed to start service
    Caused by: java.lang.IllegalArgumentException: WFLYWELD0037: Error injecting persistence unit into CDI managed bean. Can't find a persistence unit named 'pu' in deployment jpatest-1.0-SNAPSHOT.war for injection point private javax.persistence.EntityManager TestResource.entityManager"}}

将持久性单元注入CDI托管bean时出错。找不到名为“pu”的持久性单元

或者在TestResource类上使用@Vetoed时,entityManager上的指针为空。

我到底做错了什么，我不能用@PersistenceContext注入容器管理的entityManager？

我试图理解这一点，因为对其他人来说，这似乎是有效的。

请不要告诉我使用应用程序管理的事务，我可以使工作芽我需要容器管理的实体mnanager，所以我需要注入它

@PersistenceContext(UnitName=“”）

备注和编辑：

我使用的:Intellij、Wildfly、eclipselink、Java EE7、Maven、MySQL

此外，我的beans.xml中没有任何内容，只是将bean发现模式设置为ALL：

<?xml version="1.0" encoding="UTF-8"?>
<beans
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
                      http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
    bean-discovery-mode="all">
</beans>

共有1个答案

裴畅
2023-03-14

由于您没有使用支持EntityManager注入的EJB，因此必须使用EntityManagerFactory来创建和销毁EntityManager。

EntityManagerFactory factory = Persistence.createEntityManagerFactory("pu");
EntityManager entityManager = factory.createEntityManager();

使用后，请始终关闭“EntityManager”

entityManager.close();

否则，将资源转换为EJB，添加@stateless。

 类似资料：
  • 用CDI注入PersistenceContext

    问题内容： 当前，我正在使用PersistenceContext注入EntityManager。EM被完美注入。 现在，我尝试装饰Bean，然后突然没有注入em。我得到一个NullPointerException。 我知道EJB和CDI是2个完全不同的管理器，所以一个都不知道另一个。我期望@PersistenceContext是EJB注入点，而@Inject是CDI。我应该怎么做才能解决这个问题并

  • 在JAR库中注入PersistenceContext

    在包含DAO的第三部分jar库中，我在使用@PersistenceUnit注入EntityManagerFactory时遇到问题。 这是我的多模块maven项目结构。 我用CDI把所有的东西连接起来== 但是当我把@PersistenceUnit注释放在核心项目中时，它就不起作用了。（该字段为空） 当我在EJB项目中使用@PersistenceUnit时，一切正常。 我的坚持。xml文件位于EJB

  • PersistenceContext EntityManager注入NullPointerException

    问题内容： 我的战争包含以下内容： persistence.xml： web.xml： 我的TestServlet类如下： package com.test.service; 调用get（）方法时，我得到一个NullPointerException; 尚未注入EntityManager。关于我可能缺少的或如何诊断的任何建议？服务器日志中几乎没有。 我确定我在没有jboss-web.xml或web.

  • 如何使用@ EJB，@ PersistenceContext，@ Inject，@ Autowired注入@FacesValidator

    问题内容： 我怎样才能像注入的依赖，，，，等的？在我的特定情况下，我需要通过以下方式注入Spring托管的： 但是，它没有注入，而是保留了null，导致。似乎，并且t也不起作用。 如何在验证器中注入服务依赖项，以便可以访问数据库？ 问题答案： 在不被注入容器管理。你需要使其成为托管bean。使用Spring ，CDI @Named或JSF 代替，以便使其成为托管bean，从而有资格进行依赖项注入。

  • 使用AxonIq在Quarkus中无法注入CommandGateway

    我在Quarkus有一个微服务，它使用AxonIq框架实现CQRS/事件来源。我已经用Spring Boot做了，一切都没问题。我想在Quarkus中迁移它，但我在maven编译过程中出错，可能是因为Ioc。当CDI尝试创建服务时，我认为他可以注入Axon CommandGateway和QueryGateway。 配置 服务： 控制器： 屬地

  • JS函数基本定义与用法示例

    本文向大家介绍JS函数基本定义与用法示例，包括了JS函数基本定义与用法示例的使用技巧和注意事项，需要的朋友参考一下 本文实例讲述了JS函数基本定义与用法。分享给大家供大家参考，具体如下： 运行结果： 函数调用时，没有参数限制，定义函数时，即使调用了参数个数不足，也不会报错，因为参数默认为undefined类型。 上面的三种函数的定义方法虽然不同，但是其对应的底层思想是相同的，其都相当于一个变量封装

相关问答

无法从Spring Security HTTP基本身份验证示例注销？为什么？无法制作Serde Serialize工作的基本示例无法注入组件？[副本]@测试方法无法在TestNG类中注入多个类无法注册多个eureka实例

相关文章

为什么大多数示例都使用ArrayListjQuery中过滤器的基本用法示例Dapper.NET 基本多个结果示例PHP抽象类基本用法示例Python中atexit模块的基本使用示例

相关阅读

Java多对多关系示例JSF应用程序入门示例4.5.1 Intent的基本使用Struts2 <s:textfield>文本示例Lua 基本语法

相关工具

SQLite的基本使用多多输入法生成器测试用例注解testcase-annotationAndroid 繁体中文输入法一站式代码示例库

相关文档

Java 示例教程大全大数据入门指南OpenLayers 示例 中文版Python 入门基础数据挖掘十大算法
快捷导航： 新手教程 算法原理 架构设计 Java进阶 数据库进阶 大厂专栏 面试经验 编程笔记 编程问答 所有专题 文档资料 工具软件 电子书籍 小牛导航
在线工具： 房贷计算器 个税计算器 Linux命令查询 Json格式化 正则表达式 颜色转换 AES加解密 SHA1加密 MD5加密 毒鸡汤 字数统计 随机密码生成 进制转换 Base64编解码 励志句子
Copyright © 2019-2024 小牛知识库@xnip.cn. All Rights Reserved.