每次运行Junit测试时，实体管理器都为null

Question

我是Spring和JPA的新手。我使用Spring4，spring scheduler和JPA开发了一个项目，现在我想使用Junit测试用例来测试我的代码。我开始测试我的DAO方法。这是源代码：

此类执行调度程序的触发任务

public class TriggerTask {


@Autowired
private TriggerDaoBean triggerDaoBean;

public void executeDailyTask() {

    try{
    List<User> users=triggerDaoBean.getClients();
    if (null != users && users.size()>0){

        //do some task
    }

    }catch(Exception e){

    }
}}

DAO bean是：

@Stateless
public class TriggerDaoBean implements Serializable {

    private static final long serialVersionUID = 1L;


    @PersistenceContext
    private EntityManager em;

    public List<User> getUsers() {      
        List<User> userList = new ArrayList<User>();            
        Query query = em.createQuery(
                "SELECT user FROM USER user");
        userList = (List<User>)query.getResultList();
        if (null != userList && userList.size() > 0) {
            return userList;
        } else {
            return null;
        }
    }

    ....
}

我写了下面的测试用例：

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "/spring-quartz-test.xml" })
@TransactionConfiguration(defaultRollback=true)
@Transactional
public class TriggerTest {

    @Autowired
    TriggerDaoBean triggerDaoBean;

    @Test
    public void getUserListTest() {      
        triggerDaoBean.getUsers();
    }
}

spring-quartz-test.xml的内容如下：

<bean id="triggerTask" class="com.test.service.TriggerTask">
    <property name="triggerDaoBean" ref="triggerDaoBean"/>
</bean>

<bean id="triggerDaoBean"
    class="com.test.service.TriggerDaoBean">
</bean>

<bean id="runsrJobDaily" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
    <property name="targetObject" ref="triggerTask" />
    <property name="targetMethod" value="executeDailyTask" />
</bean>

而persistence.xml如下：

<persistence xmlns="http://java.sun.com/xml/ns/persistence"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
    <persistence-unit name="forge-default" transaction-type="JTA" >
     <description>Forge Persistence Unit</description>
     <provider>org.hibernate.ejb.HibernatePersistence</provider>
     <jta-data-source>java:/MySqlDS</jta-data-source>


    <class>com.test.persistence.entity.User</class>

    <properties>
     <!--  <property name="hibernate.hbm2ddl.auto" value="create-drop"/> -->
      <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
      <!--
      <property name="hibernate.ejb.cfgfile" value="modified.hibernate.cfg.xml"/>
      --> 
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.format_sql" value="true"/>
      <property name="hibernate.transaction.flush_before_completion" value="true"/>
    </properties>

  </persistence-unit>
</persistence>

java:/MySqlDS是数据源的JNDI名称。每次运行我的测试时，NullPointerException都会出现在EntityManager中。

难道我做错了什么？

Answer 1

我是我的情况，你需要在你的测试类上附加两个注释。

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = SpringBootApplicationClass.class)

Answer 2

你必须在spring中定义你的entityManager，我没有在你发布的代码中看到entityManager，你可以这样做

<tx:annotation-driven transaction-manager="txManager"/>

<bean id="txManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceUnitName" value="example" />
</bean>

<bean id="entityManager" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

请注意，您在persistence.xml中将事务类型定义为JTA，您真的需要全局事务吗？如果没有，删除persistence.xml中的transaction-type="JTA"

另一件事，出于测试目的，最好使用像H2这样的测试数据库。您可以在src/test/resources中的测试弹簧上下文中定义它

<bean id="txManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="persistenceXmlLocation" value="classpath:META-INF/persistence-test.xml"/>
        <property name="persistenceUnitName" value="example-test" />
        <property name="dataSource" ref="dataSourceTest"/>
</bean>

<bean id="entityManager" class="org.springframework.orm.jpa.support.SharedEntityManagerBean">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<bean id="dataSourceTest" class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
        <property name="driverClass" value="org.h2.Driver"/>
        <property name="url" value="jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE"/>
        <property name="username" value="sa"/>
        <property name="password" value=""/>
</bean>

<bean id="org.h2.tools.Server-WebServer" class="org.h2.tools.Server"
        factory-method="createWebServer" init-method="start" lazy-init="true">
        <constructor-arg value="-web,-webAllowOthers,-webPort,11111" />
</bean>

这样你可以控制数据库状态，每个测试都会在内存中创建一个数据库，你可以在import.sql中定义一个src/test/resource，以便用测试数据填充你的表。您必须在pom.xml中添加de h2依赖项

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.3.174</version>
    <scope>test</scope>
</dependency>