如何使用 Spring @Configuration 而不是 XML 配置检索 JNDI

Question

我已经开始开发一个新的 Spring 3.2.4 应用程序，并尝试使用基于 Java 的配置，而不是我过去使用的 XML 文件。但是，我在过渡时遇到了麻烦。

使用 XML，我将其编码如下：

<!-- application datasource -->
<bean id="dataSource.jndi" class="org.springframework.jndi.JndiObjectFactoryBean" scope="singleton" lazy-init="true">
    <property name="jndiName" value="java:comp/env/jdbc/liment" />
</bean>

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

<tx:annotation-driven mode="aspectj" transaction-manager="transactionManager"/>
<bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" id="entityManagerFactory">
    <property name="persistenceUnitName" value="persistenceUnit"/>
    <property name="dataSource" ref="dataSource.jndi"/>
</bean>

但是，我非常想弄清楚如何在 Java 中做到这一点。我正在尝试复制配置，但遇到了麻烦：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages={"com.ia"})
public class AppConfigJPA {
    @Bean
    public DataSource dataSource() {
        // configure and return the necessary JDBC DataSource
        JndiObjectFactoryBean dataSource = new JndiObjectFactoryBean();
        dataSource.setJndiName("java:comp/env/jdbc/liment");
        try {
            dataSource.afterPropertiesSet();
        } catch (IllegalArgumentException | NamingException e) {
            // rethrow
            throw new RuntimeException(e);
        }
        return (DataSource)dataSource.getObject();
    }

    @Bean
    public EntityManagerFactory entityManagerFactory(){
        LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
        emf.setPersistenceUnitName("persistenceUnit");
        emf.setDataSource(dataSource());
            emf.afterPropertiesSet
        return emf.getObject();
    }

    @Bean
    public PlatformTransactionManager transactionManager() {
        return new JpaTransactionManager(entityManagerFactory());
    }

}

但是，我收到以下错误消息：

Caused by: java.lang.IllegalStateException: No persistence exception translators found in bean factory. Cannot perform exception translation.
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.detectPersistenceExceptionTranslators(PersistenceExceptionTranslationInterceptor.java:142)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.setBeanFactory(PersistenceExceptionTranslationInterceptor.java:117)
    at org.springframework.data.repository.core.support.PersistenceExceptionTranslationRepositoryProxyPostProcessor.<init>(PersistenceExceptionTranslationRepositoryProxyPostProcessor.java:44)
    at org.springframework.data.repository.core.support.TransactionalRepositoryFactoryBeanSupport.setBeanFactory(TransactionalRepositoryFactoryBeanSupport.java:85)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1502)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1470)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
    ... 33 more

我错过了什么或做错了什么？

编辑

在@SotiriosDelimanolis 回复之后，我修改了我的代码以阅读以下内容：

@Autowired DataSource dataSource;
@Autowired EntityManagerFactory entityManagerFactory;


@Bean
public JndiObjectFactoryBean dataSource() {
    // configure and return the necessary JDBC DataSource
    JndiObjectFactoryBean dataSource = new JndiObjectFactoryBean();
    dataSource.setJndiName("java:comp/env/jdbc/josak");
    return dataSource;
}

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(){
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setPersistenceUnitName("persistenceUnit");
    emf.setDataSource(dataSource);
    return emf;
}

@Bean
public PlatformTransactionManager transactionManager() {
    return new JpaTransactionManager(entityManagerFactory);
}

但是现在我得到了 Autowired 异常：

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: javax.sql.DataSource com.ia.system.configuration.AppConfigJPA.dataSource; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.sql.DataSource] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:514)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
    ... 31 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.sql.DataSource] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:988)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:858)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:486)
    ... 33 more

Answer 1

这是一个奇怪的设计（针对PersistenceExceptionTranslator），我不立即理解，但这是解决方案。

您的LocalContainerEntityManagerFactoryBean 是FactoryBean，但也是PersistenceExceptionTranslator（实现两者）。但是您并没有将 LocalContainerEntityManagerFactoryBean 放入您的上下文中，您只是获取它创建的对象。

代替

@Bean
public EntityManagerFactory entityManagerFactory(){
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setPersistenceUnitName("persistenceUnit");
    emf.setDataSource(dataSource());
        emf.afterPropertiesSet
    return emf.getObject();
}

做

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory(){
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setPersistenceUnitName("persistenceUnit");
    emf.setDataSource(dataSource());
    return emf;
}

@Autowired
private EntityManagerFactory entityManagerFactory;

@Bean
public PlatformTransactionManager transactionManager() {
    return new JpaTransactionManager(entityManagerFactory);
}

Spring 将负责调用 afterPropertiesSet() 和 getObject() 以将 EntityManagerFactory bean 放入上下文中。

基本上你会得到两个 bean，一个 EntityManagerFactory 和一个 LocalContainerEntityManagerFactoryBean。您的 JPA 配置需要在上下文中使用 PersistenceExceptionTranslator bean。 LocalContainerEntityManagerFactoryBean 将满足这一要求。

---

仅供参考，您可以为您的 JndiObjectFactoryBean 或任何其他 FactoryBean 做同样的事情。

Answer 2

请参考以下链接 -

http://forum.spring.io/forum/spring-projects/container/724356-how-to-use-javaconfig-to-declare-a-jndi-datasource

需要像这样创建数据源 -

@Bean
    public DataSource dataSource() {
        final JndiDataSourceLookup dsLookup = new JndiDataSourceLookup();
        dsLookup.setResourceRef(true);
        DataSource dataSource = dsLookup.getDataSource("jdbc/yourJdbcGoesHere");
        return dataSource;
    }