创建EntityManager以及持久化

Question

我是 Spring 和 JPA 的新手。我正在创建一个示例并尝试将其转换为 JPA。使用会话工厂它工作正常，但是当我使用 persistence.xml 转换为实体管理器时，它不工作并抛出异常。

ERROR [io.undertow.request] (default task-4) UT005023: Exception handling request to /Spring-hibernate-integration-helloworld/saveUser.html: org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.persistence.TransactionRequiredException: no transaction is in progress
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982) [spring-webmvc-4.2.0.RELEASE.jar:4.2.0.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872) [spring-webmvc-4.2.0.RELEASE.jar:4.2.0.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) [jboss-servlet-api_3.1_spec-1.0.0.Final.jar:1.0.0.Final]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.2.0.RELEASE.jar:4.2.0.RELEASE]

这是我的 dispatcher-servlet.xml

    <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <context:property-placeholder location="classpath:jdbc.properties" />
    <context:component-scan base-package="com.beingjavaguys" />

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

    <bean id="jpaVendorAdapter"
        class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="database" value="HSQL" />
        <property name="databasePlatform" value="org.hibernate.dialect.HSQLDialect" />
    </bean>

    <bean id="jpaDialect" class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />

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

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

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

    <bean id="jspViewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/view/" />
        <property name="suffix" value=".jsp" />
    </bean>



    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${database.driver}" />
        <property name="url" value="${database.url}" />
        <property name="username" value="${database.user}" />
        <property name="password" value="${database.password}" />
    </bean>

    <!-- <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="annotatedClasses">
            <list>
                <value>com.beingjavaguys.domain.User</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
            </props>
        </property>
    </bean>

    <bean id="hibernateTransactionManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean> -->
</beans>

这是我的 persistence.xml 文件：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    version="1.0">
    <persistence-unit name="personPersistenceUnit"  transaction-type="RESOURCE_LOCAL">
        <class>com.beingjavaguys.domain.User</class>
    </persistence-unit>
</persistence>

这是我的道课：

public class UserDaoImpl implements UserDao {
    @PersistenceContext
    private EntityManager entityManager;

    @Override
    public void saveUser(User user) {
        entityManager.persist(user);
        entityManager.flush();
    }

    @Override
    public List<User> getUser() {
        return new ArrayList<User>();
    }

}

我错过了什么？

Answer 1

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

这个配置只是奖牌的一面，你在课堂上也需要另一面：

public class UserDaoImpl implements UserDao {
    @PersistenceContext
    private EntityManager entityManager;

    @Transactional // <-- this is new
    @Override
    public void saveUser(User user) {
        entityManager.persist(user);
        entityManager.flush();
    }

    @Override
    public List<User> getUser() {
        return new ArrayList<User>();
    }

}