Question

我正在创建一个基本的spring-maven项目，它应该作为java应用程序运行（在进程中，而不是在Web服务器上运行）。

我的应用程序上下文位于我的类路径中的resources文件夹下：

<?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:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:ox="http://www.springframework.org/schema/oxm"
    xsi:schemaLocation="
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
   http://www.springframework.org/schema/oxm http://www.springframework.org/schema/oxm/spring-oxm-3.1xsd">


<!-- Root Context: defines shared resources visible to all other web components -->

<!-- Context -->
<context:component-scan base-package="me.co.nutrition" />

<!-- Properties -->
<context:property-placeholder
    location="classpath:/nutrition.accumulation.properties" />

<!-- DB -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    <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="persistenceUnitManager"
    class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager">
    <property name="defaultPersistenceUnitName" value="nutrition-pu"/>
    <property name="persistenceXmlLocation" value="classpath:META-INF/persistence.xml"/>
    <property name="defaultDataSource" ref="dataSource" />
</bean>

<!-- JPA -->
<bean id="entityManager"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="persistenceUnitManager" ref="persistenceUnitManager" />
    <property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
</bean>

<!-- jpaVendorAdapter (works in conjunction with the persistence.xml) -->
<bean id="jpaVendorAdapter"
    class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
    <property name="database" value="${jpa.database}" />
    <property name="showSql" value="${jpa.showSql}" />
    <property name="databasePlatform" value="${jpa.dialect}" />
    <property name="generateDdl" value="${jpa.generateDdl}" />
</bean>

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

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

<bean id="persistenceAnnotation" class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

</beans>

我创建了一个META-INF文件夹作为源文件夹，并将此文件夹添加到我的类路径中。我在这个文件夹下创建了我的persistence.xml文件。

这是我的persistence.xml：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
    version="2.0">

<persistence-unit name="nutrition-pu" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
</persistence-unit>
</persistence>

如上所述，它位于我的类路径中的META-INF文件夹下。这是我的.classpath文件：

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry kind="src" output="target/classes" path="src/main/java"/>
    <classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
    <classpathentry kind="src" path="META-INF"/>
    <classpathentry kind="src" path="resources"/>
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
    <classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER"/>
    <classpathentry kind="output" path="target/classes"/>
</classpath>

你可以看到META-INF文件夹在那里。我创建了一个简单的main运行：

public static void main(String[] args) throws Exception {

            ApplicationContext context = new ClassPathXmlApplicationContext("accumulationApplicationContext.xml");

...
}

当我运行它时，在尝试加载应用程序上下文时，我得到一个异常，说明无法找到或解析persistence.xml：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'persistenceUnitManager' defined in class path resource [accumulationApplicationContext.xml]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Cannot parse persistence unit from class path resource [META-INF/persistence.xml]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322)
    ... 30 more
Caused by: java.lang.IllegalArgumentException: Cannot parse persistence unit from class path resource [META-INF/persistence.xml]
    at org.springframework.orm.jpa.persistenceunit.PersistenceUnitReader.readPersistenceUnitInfos(PersistenceUnitReader.java:141)
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.readPersistenceUnitInfos(DefaultPersistenceUnitManager.java:380)
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:341)
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:326)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452)
    ... 37 more
Caused by: java.io.FileNotFoundException: class path resource [META-INF/persistence.xml] cannot be opened because it does not exist
    at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:158)
    at org.springframework.orm.jpa.persistenceunit.PersistenceUnitReader.readPersistenceUnitInfos(PersistenceUnitReader.java:129)

我无法理解这个问题。我很确定我有right结构，为什么我的persistence.xml不能加载？

提前致谢！

更新：

感谢Boris我得到了它的工作。似乎我在错误的路径下创建了META-INF。这件事发生在我错过了解Eclipse项目结构的东西。 This是正确的结构。我希望这有助于某人......

Answer 1

您的META-INF文件夹应直接位于源文件夹下，而不是单独作为源文件夹。

请参阅Where do I put META-INF in Eclipse?

更新 From JPA 2.0 Specification

8.2＆lt; ...＆gt;持久性单元由persistence.xml文件定义。 jar文件或目录   META-INF目录包含persistence.xml文件，称为持久性单元的根。   在Java EE环境中，持久性单元的根必须是以下之一：


EJB-JAR文件

WAR文件的WEB-INF / classes目录

WAR文件的WEB-INF / lib目录中的jar文件

EAR库目录中的jar文件

应用程序客户端jar文件

8.2.1＆lt; ...＆gt; persistence.xml文件定义了持久性单元。 persistence.xml文件位于持久性单元根目录的 META-INF 目录。

因此，如何配置项目没有任何区别，只有生成的jar才重要。如果您使用的是maven，通常的做法是使用META-INF的 src / main / resources 文件夹。

无法打开META-INF / persistence.xml，因为它不存在

1 个答案: