JBoss7.1.0:无法在子部署中找到名为null的持久性单元

Question

我有一个项目，里面有三个模块:工厂-ear，工厂-ejb和工厂-web.它以EAR的形式部署到JBoss7中，内部有ejb.jar和web.war。当我试图在我的EJB类中获得EntityManager时

@PersistenceContext(unitName = "manager1")
private EntityManager em;

我搞错了

JBAS011440:在部署"factory.ear“的”工厂-EJB1.0-SNAPSHOT.jar“子部署中找不到一个名为manager1的持久性单元

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="manager1" transaction-type="JTA">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>java:jboss/datasources/PostgresDS</jta-data-source>
        <class>com.test.model.Car</class>
        <class>com.test.model.Engine</class>
        <class>com.test.model.Body</class>
        <class>com.test.model.Transmission</class>
        <properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
         <property name="hibernate.show_sql" value="true" />
         <property name="hibernate.hbm2ddl.auto" value="update"/>
        </properties>
    </persistence-unit>
</persistence>

persistence.xml位于app_name/factory_ear/META中。

我读到过，这可能是类加载器的问题。我有相同的JPA API依赖关系，并在ear和web模块中提供了作用域。

  <dependency>
     <groupId>org.hibernate.javax.persistence</groupId>
     <artifactId>hibernate-jpa-2.0-api</artifactId>
     <scope>provided</scope>
  </dependency> 

但我没能移除其中的一个。两者都是构建所必需的。

Body.java

@Entity
@Table(name = "body")
public class Body {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "type")
    private String type;

    @Column(name = "color")
    private String color;

    @Column(name = "doors_num")
    private Integer doorsNumber;

    @Column(name = "vin")
    private Integer vin;

    @OneToMany(mappedBy = "body")
    private Set<Car> cars;

    /**
     * @return the id
     */
    public Integer getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(Integer id) {
        this.id = id;
    }

    /**
     * @return the type
     */
    public String getType() {
        return type;
    }

    /**
     * @param type the type to set
     */
    public void setType(String type) {
        this.type = type;
    }

    /**
     * @return the color
     */
    public String getColor() {
        return color;
    }

    /**
     * @param color the color to set
     */
    public void setColor(String color) {
        this.color = color;
    }

    /**
     * @return the doorsNumber
     */
    public Integer getDoorsNumber() {
        return doorsNumber;
    }

    /**
     * @param doorsNumber the doorsNumber to set
     */
    public void setDoorsNumber(Integer doorsNumber) {
        this.doorsNumber = doorsNumber;
    }

    /**
     * @return the vin
     */
    public Integer getVin() {
        return vin;
    }

    /**
     * @param vin the vin to set
     */
    public void setVin(Integer vin) {
        this.vin = vin;
    }

    /**
     * @return the cars
     */
    public Set<Car> getCars() {
        return cars;
    }

    /**
     * @param cars the cars to set
     */
    public void setCars(Set<Car> cars) {
        this.cars = cars;
    }
}

Car.java

public class Car {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "model")
    private String model;

    @ManyToOne
    @JoinColumn(name = "engine_id")
    private Engine engine;

    @ManyToOne
    @JoinColumn(name = "body_id")
    private Body body;

    @ManyToOne
    @JoinColumn(name = "transmission_id")
    private Transmission transmission;

    /**
     * @return the id
     */
    public Integer getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(Integer id) {
        this.id = id;
    }

    /**
     * @return the model
     */
    public String getModel() {
        return model;
    }

    /**
     * @param model the model to set
     */
    public void setModel(String model) {
        this.model = model;
    }

    /**
     * @return the engine
     */
    public Engine getEngine() {
        return engine;
    }

    /**
     * @param engine the engine to set
     */
    public void setEngine(Engine engine) {
        this.engine = engine;
    }

    /**
     * @return the body
     */
    public Body getBody() {
        return body;
    }

    /**
     * @param body the body to set
     */
    public void setBody(Body body) {
        this.body = body;
    }

    /**
     * @return the transmission
     */
    public Transmission getTransmission() {
        return transmission;
    }

    /**
     * @param transmission the transmission to set
     */
    public void setTransmission(Transmission transmission) {
        this.transmission = transmission;
    }
}

Answer 1

此问题不是由maven依赖关系引起的。

EAR文件中META目录的内容通常是任何类加载程序都无法访问的。

因此，您不能将persistence.xml文件放在EAR文件的META目录中。将其移到EJB文件的META目录中。