Java 如何在没有persistence.xml的情况下配置Spring？

How to configure Spring without persistence.xml?

提问by membersound

I'm trying to set up spring xml configuration without having to create a futher persistence.xml. But I'm constantly getting the following exception, even though I included the database properties in the spring.xml

我正在尝试设置 spring xml 配置，而无需创建进一步的persistence.xml. 但是我不断收到以下异常，即使我在spring.xml

    Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in file [C:\Users\me\workspace\app\src\main\webapp\WEB-INF\applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: No persistence units parsed from {classpath*:META-INF/persistence.xml}

spring.xml:

弹簧.xml：

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

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
     <property name="jpaProperties">
         <props>
            <prop key="hibernate.dialect">${hibernate.dialect}</prop>
            <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
            <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
            <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
         </props>
      </property>
    </bean>

What am I missing here?

我在这里缺少什么？

采纳答案by Zaki

Specify the "packagesToScan" & "persistenceUnitName" properties in the entityManagerFactory bean definition.

在 entityManagerFactory bean 定义中指定“packagesToScan”和“persistenceUnitName”属性。

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

        <property name="persistenceUnitName" value="myPersistenceUnit" />
        <property name="packagesToScan" >
            <list>
                <value>org.mypackage.*.model</value>
            </list>
        </property>

        <property name="jpaProperties">
            <props>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
            </props>
        </property>
    </bean>

Note that this is for Spring version > 3.1

请注意，这是针对 Spring 版本 > 3.1

回答by MariuszS

From Spring Guide Accessing Data with JPA

来自 Spring Guide使用 JPA 访问数据

@Configuration
@EnableJpaRepositories
public class Application {

    @Bean
    public DataSource dataSource() {
        return new EmbeddedDatabaseBuilder().setType(H2).build();
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource, JpaVendorAdapter jpaVendorAdapter) {
        LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
        lef.setDataSource(dataSource);
        lef.setJpaVendorAdapter(jpaVendorAdapter);
        lef.setPackagesToScan("hello");
        return lef;
    }

    @Bean
    public JpaVendorAdapter jpaVendorAdapter() {
        HibernateJpaVendorAdapter hibernateJpaVendorAdapter = new HibernateJpaVendorAdapter();
        hibernateJpaVendorAdapter.setShowSql(false);
        hibernateJpaVendorAdapter.setGenerateDdl(true);
        hibernateJpaVendorAdapter.setDatabase(Database.H2);
        return hibernateJpaVendorAdapter;
    }

Spring Boot

弹簧靴

With Spring Boot enabled application this is even easier:

使用启用 Spring Boot 的应用程序，这更容易：

Sample application.yaml

样本 application.yaml

spring:
    datasource:
        url: jdbc:h2:mem:test
        username: sa
        password: sa
        driver-class-name: org.h2.Driver
    jpa:
        database: H2
        show-sql: false
        hibernate:
            format_sql: true
            ddl-auto: auto

回答by Mustafa

MariuszS' answer is good except that the entityManagerFactorymethod should return EntityManagerFactory. To do that it can be written like this:

MariuszS 的回答很好，只是该entityManagerFactory方法应该返回 EntityManagerFactory。为此，它可以这样写：

@Bean
public EntityManagerFactory entityManagerFactory(DataSource dataSource, JpaVendorAdapter jpaVendorAdapter) {
    LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
    lef.setDataSource(dataSource);
    lef.setJpaVendorAdapter(jpaVendorAdapter);
    lef.setPackagesToScan("hello");
    return lef.object();
}

For future audience: below code worked:

对于未来的观众：以下代码有效：

@Bean (name = "entityManagerFactory")
public EntityManagerFactory entityManagerFactory(DataSource dataSource, JpaVendorAdapter jpaVendorAdapter)
{
    LocalContainerEntityManagerFactoryBean lef = new LocalContainerEntityManagerFactoryBean();
    lef.setDataSource(dataSource);
    lef.setJpaVendorAdapter(jpaVendorAdapter);
    lef.setPackagesToScan("*.models*");
    lef.afterPropertiesSet(); // It will initialize EntityManagerFactory object otherwise below will return null
    return lef.getObject();
}

回答by Vlad Mihalcea

Assuming that you have a PersistenceProviderimplementation (e.g. org.hibernate.jpa.HibernatePersistenceProvider), you can use the PersistenceProvider#createContainerEntityManagerFactory(PersistenceUnitInfo info, Map map)method to bootstrap an EntityManagerFactorywithout needing a persistence.xml.

假设您有一个PersistenceProvider实现（例如org.hibernate.jpa.HibernatePersistenceProvider），您可以使用PersistenceProvider#createContainerEntityManagerFactory(PersistenceUnitInfo info, Map map)方法来引导 anEntityManagerFactory而不需要persistence.xml.

However, it's annoying that you have to implement the PersistenceUnitInfointerface, so you are better off using Spring or Hibernate which both support bootstrapping JPA without a persistence.xmlfile:

但是，您必须实现PersistenceUnitInfo接口很烦人，因此最好使用 Spring 或 Hibernate，它们都支持在没有persistence.xml文件的情况下引导 JPA ：

this.nativeEntityManagerFactory = provider.createContainerEntityManagerFactory(
    this.persistenceUnitInfo, 
    getJpaPropertyMap()
);

Where the PersistenceUnitInfois implemented by the Spring-specific MutablePersistenceUnitInfoclass.

凡PersistenceUnitInfo是由Spring特定的实施MutablePersistenceUnitInfo类。

Check out this articlefor a nice demonstration of how you can achieve this goal with Hibernate.

查看这篇文章，以很好地演示如何使用 Hibernate 实现这一目标。