java - 测试中没有 EntityManager 的持久性提供程序

Question

我是 JavaEE 新手，现在正在阅读“Goncalves A. Beginning Java EE 7”一书。我在为实体编写单元测试时遇到问题。我正在使用 NetBeans 8.2、Hibernate 4.3 和 PostgreSQL 10.2。

该项目是通过新建项目 -> Java Web -> Web 应用程序使用 JSF 和 Hibernate 库创建的。

这是我的代码:

Book.java

@Entity
public class Book implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @NotNull
    private String title;
    private Integer price;

    public Book(String title, Integer price) {
        this.title = title;
        this.price = price;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public Integer getPrice() {
        return price;
    }

    public void setPrice(Integer price) {
        this.price = price;
    }



    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Book)) {
            return false;
        }
        Book other = (Book) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "epic.Book[ id=" + id + " ]";
    }

}

BookTest.java

public class BookTest {

    private static EntityManagerFactory emf = Persistence.createEntityManagerFactory("EpicWebAppTestPU");
    private EntityManager em;
    private EntityTransaction tx;

    @Before
    public void initEntityManager() throws Exception {
        em = emf.createEntityManager();
        tx = em.getTransaction();
    }

    @After
    public void closeEntityManager() throws Exception {
        if (em != null) {
            em.close();
        }
    }

    @Test
    public void shouldCreateBook() throws Exception {

        Book book = new Book("EpicBook", 9999);

        tx.begin();
        em.persist(book);
        tx.commit();
        Assert.assertNotNull( book.getId());
    }
}

\src\conf\persistence.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="EpicWebAppPU" transaction-type="JTA">
  <provider>org.hibernate.ejb.HibernatePersistence</provider>        


    <class>com.epic.Book</class>
    <properties>
        <property name="javax.persistence.schema-generation-action" value="drop-and-create"/>
        <property name="javax.persistence.schema-generation-target" value="database"/>
        <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/cosuket;create=true"/>
                <property name="javax.persistence.jdbc.user" value="root"/>
        <property name="javax.persistence.jdbc.password" value="toor"/>
    </properties>
  </persistence-unit>

  <persistence-unit name="EpicWebAppTestPU" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>com.epic.Book</class>
    <properties>
        <property name="javax.persistence.schema-generation-action" value="drop-and-create"/>
        <property name="javax.persistence.schema-generation-target" value="database"/>
        <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/cosuketTest;create=true"/>
                <property name="javax.persistence.jdbc.user" value="root"/>
        <property name="javax.persistence.jdbc.password" value="toor"/>
    </properties>
</persistence-unit>

</persistence>

但是测试失败并显示消息:

Null Test: Caused an ERROR null java.lang.ExceptionInInitializerError at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:264) Caused by: javax.persistence.PersistenceException: No Persistence provider for EntityManager named EpicWebAppTestPU atjavax.persistence.Persistence.createEntityManagerFactory(Persistence.java:61) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39) at epic.BookTest.(BookTest.java:20)

我尝试使用 <provider>org.hibernate.ejb.HibernatePersistence</provider>和<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> ，但结果是相同的:未找到 EpicWebAppTestPU。我做错了什么？

已更新。我用maven重新创建了项目。

pom.xml

<?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.epic</groupId>
    <artifactId>EpicWebMaven</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>EpicWebMaven</name>

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

    <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>4.3.1.Final</version>
        </dependency>
        <dependency>
            <groupId>unknown.binary</groupId>
            <artifactId>hibernate-jpamodelgen-4.3.1.Final</artifactId>
            <version>SNAPSHOT</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-core</artifactId>
            <version>1.3</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.2.jre7</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <compilerArguments>
                        <endorseddirs>${endorsed.dir}</endorseddirs>
                    </compilerArguments>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <phase>validate</phase>
                        <goals>
                            <goal>copy</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${endorsed.dir}</outputDirectory>
                            <silent>true</silent>
                            <artifactItems>
                                <artifactItem>
                                    <groupId>javax</groupId>
                                    <artifactId>javaee-endorsed-api</artifactId>
                                    <version>7.0</version>
                                    <type>jar</type>
                                </artifactItem>
                            </artifactItems>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>unknown-jars-temp-repo</id>
            <name>A temporary repository created by NetBeans for libraries and jars it could not identify. Please replace the dependencies in this repository with correct ones and delete this repository.</name>
            <url>file:${project.basedir}/lib</url>
        </repository>
    </repositories>
</project>

现在我在构建项目时遇到了另一个错误。哪里BookTest.java:29是 em = emf.createEntityManager();

java.lang.NullPointerException
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus(JtaStatusHelper.java:76)
    at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.isActive(JtaStatusHelper.java:118)
    at org.hibernate.engine.transaction.internal.jta.CMTTransaction.join(CMTTransaction.java:149)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.joinTransaction(AbstractEntityManagerImpl.java:1602)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.postInit(AbstractEntityManagerImpl.java:210)
    at org.hibernate.jpa.internal.EntityManagerImpl.<init>(EntityManagerImpl.java:91)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.internalCreateEntityManager(EntityManagerFactoryImpl.java:345)
    at org.hibernate.jpa.internal.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:313)
    at moe.dk_x86.epicwebmaven.BookTest.initEntityManager(BookTest.java:29)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:53)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:123)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:104)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164)
    at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110)
    at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:175)
    at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:107)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:68)

Answer 1

org.hibernate.ejb.HibernatePersistence 应该可以工作。

尝试使用以下提供程序:

org.hibernate.jpa.HibernatePersistenceProvider

如果仍然无法正常工作，则可能缺少一个 jar。

检查 hibernate-entitymanager jar 是否存在。