EntityManagerFactory的init方法中的NullPointerException

Question

尝试运行Spring Data JPA项目时出现以下错误。我是Spring的新手，所以我想我做错了什么。

"C:\Program Files\Java\jdk1.8.0_25\bin\java" -Didea.launcher.port=7536 "-Didea.launcher.bin.path=C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.5\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_25\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\rt.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_25\jre\lib\ext\zipfs.jar;D:\dev\workspace\StringJPA_2\target\classes;C:\Users\oanacioara\.m2\repository\org\slf4j\slf4j-log4j12\1.6.1\slf4j-log4j12-1.6.1.jar;C:\Users\oanacioara\.m2\repository\org\slf4j\slf4j-api\1.6.1\slf4j-api-1.6.1.jar;C:\Users\oanacioara\.m2\repository\log4j\log4j\1.2.16\log4j-1.2.16.jar;C:\Users\oanacioara\.m2\repository\org\springframework\data\spring-data-jpa\1.7.1.RELEASE\spring-data-jpa-1.7.1.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\data\spring-data-commons\1.9.1.RELEASE\spring-data-commons-1.9.1.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-core\4.0.7.RELEASE\spring-core-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-beans\4.0.7.RELEASE\spring-beans-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\slf4j\jcl-over-slf4j\1.7.7\jcl-over-slf4j-1.7.7.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-orm\4.0.7.RELEASE\spring-orm-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-jdbc\4.1.1.RELEASE\spring-jdbc-4.1.1.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-tx\4.0.7.RELEASE\spring-tx-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-context\4.0.7.RELEASE\spring-context-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-aop\4.0.7.RELEASE\spring-aop-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\aopalliance\aopalliance\1.0\aopalliance-1.0.jar;C:\Users\oanacioara\.m2\repository\org\springframework\spring-expression\4.0.7.RELEASE\spring-expression-4.0.7.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\aspectj\aspectjrt\1.8.2\aspectjrt-1.8.2.jar;C:\Users\oanacioara\.m2\repository\org\springframework\data\spring-data-commons-core\1.4.0.RELEASE\spring-data-commons-core-1.4.0.RELEASE.jar;C:\Users\oanacioara\.m2\repository\org\hibernate\javax\persistence\hibernate-jpa-2.0-api\1.0.1.Final\hibernate-jpa-2.0-api-1.0.1.Final.jar;C:\Users\oanacioara\.m2\repository\org\hibernate\hibernate-entitymanager\4.3.7.Final\hibernate-entitymanager-4.3.7.Final.jar;C:\Users\oanacioara\.m2\repository\org\jboss\logging\jboss-logging\3.1.3.GA\jboss-logging-3.1.3.GA.jar;C:\Users\oanacioara\.m2\repository\org\jboss\logging\jboss-logging-annotations\1.2.0.Beta1\jboss-logging-annotations-1.2.0.Beta1.jar;C:\Users\oanacioara\.m2\repository\org\hibernate\hibernate-core\4.3.7.Final\hibernate-core-4.3.7.Final.jar;C:\Users\oanacioara\.m2\repository\org\jboss\spec\javax\transaction\jboss-transaction-api_1.2_spec\1.0.0.Final\jboss-transaction-api_1.2_spec-1.0.0.Final.jar;C:\Users\oanacioara\.m2\repository\dom4j\dom4j\1.6.1\dom4j-1.6.1.jar;C:\Users\oanacioara\.m2\repository\xml-apis\xml-apis\1.0.b2\xml-apis-1.0.b2.jar;C:\Users\oanacioara\.m2\repository\org\hibernate\common\hibernate-commons-annotations\4.0.5.Final\hibernate-commons-annotations-4.0.5.Final.jar;C:\Users\oanacioara\.m2\repository\org\hibernate\javax\persistence\hibernate-jpa-2.1-api\1.0.0.Final\hibernate-jpa-2.1-api-1.0.0.Final.jar;C:\Users\oanacioara\.m2\repository\org\javassist\javassist\3.18.1-GA\javassist-3.18.1-GA.jar;C:\Users\oanacioara\.m2\repository\antlr\antlr\2.7.7\antlr-2.7.7.jar;C:\Users\oanacioara\.m2\repository\org\jboss\jandex\1.1.0.Final\jandex-1.1.0.Final.jar;C:\Users\oanacioara\.m2\repository\com\h2database\h2\1.3.176\h2-1.3.176.jar;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 13.1.5\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain hello.Application
log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in file [D:\dev\workspace\StringJPA_2\src\main\resources\applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1554)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:975)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:752)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:140)
    at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:84)
    at hello.Application.main(Application.java:9)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.NullPointerException
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:126)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
    at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1887)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1845)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:852)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:845)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:398)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:844)
    at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:152)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:336)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1613)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1550)
    ... 17 more

Process finished with exit code 1

这是applicationContext.xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:jpa="http://www.springframework.org/schema/data/jpa"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
        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/data/jpa
        http://www.springframework.org/schema/data/jpa/spring-jpa-1.1.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">

    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations" value="classpath*:datasource.properties"/>
    </bean>

    <bean id = "driver"
          class="org.h2.Driver"/>

    <bean id = "dataSource"
          class = "org.springframework.jdbc.datasource.SimpleDriverDataSource"
          p:driver-ref="driver"
          p:username="${dataSource.username}"
          p:url="${dataSource.url}"
          p:password="${dataSource.password}"/>

    <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <property name="showSql" value="true"/>
        <property name="generateDdl" value="true"/>
        <property name="database" value="MYSQL"/>
    </bean>

    <!-- Use this EMF configuration as an alternative to using persistence.xml. -->
    <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
          p:dataSource-ref="dataSource"
          p:packagesToScan="hello"
          p:jpaVendorAdapter-ref="jpaVendorAdapter"
          p:persistenceUnitName="MyPersistanceUnit"/>

    <bean id="transactionManager"
          class="org.springframework.orm.jpa.JpaTransactionManager"
          p:entityManagerFactory-ref="entityManagerFactory" />

    <tx:annotation-driven />

    <jpa:repositories base-package="hello" />
    <context:component-scan base-package="hello" />
</beans>

这是POM的一部分：

<dependencies>
    <!-- SLF4J dependency -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.6.1</version>
    </dependency>
    <!-- Spring Data Dependency -->
    <dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-jpa</artifactId>
        <version>1.7.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.data</groupId>
        <artifactId>spring-data-commons-core</artifactId>
        <version>1.4.0.RELEASE</version>
    </dependency>
    <!--Hibernate Persistence-->
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.0-api</artifactId>
        <version>1.0.1.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>4.3.7.Final</version>
    </dependency>
    <!--The H2 database-->
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <version>1.3.176</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.1.1.RELEASE</version>
    </dependency>

</dependencies>

此行抛出异常：

ApplicationContext context = new FileSystemXmlApplicationContext("src/main/resources/applicationContext.xml");

有什么可能出错的想法吗？