在JAR中使用Tomcat连接池（来自Web应用程序的共享conf，春季配置）

Question

我在Tomcat上部署了一些Web应用程序，它们都使用来自Tomcat连接池的相同数据库访问配置：

<bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
  <property name="jndiName" value="java:comp/env/jdbc/postgres"/>
  <property name="lookupOnStartup" value="true"/>
  <property name="proxyInterface" value="javax.sql.DataSource"/>
</bean>

（每个项目中的web.xml和Tomcat中的context.xml均已正确设置，因为一切正常：））。

我也想对在同一服务器上运行的JAR文件使用此连接。 在JAR中，我也使用Spring，但是如果在这样的代码中使用上述dataSource定义，则会出现以下错误：

    String[] springConfig = { "file:/var/pro/conf/data-access.xml"};        

    context = new ClassPathXmlApplicationContext(springConfig);

我收到以下错误：

Exception in thread "main" java.lang.ExceptionInInitializerError
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:247)
        at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in URL [file:/var/pro/conf/data-access.xml]: Invocation of init method failed; nested exception is javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file:  java.naming.factory.initial
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1482)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:610)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:93)
        at com.proj.job.Start.<clinit>(Start.java:73)
        ... 3 more
Caused by: javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file:  java.naming.factory.initial
        at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:645)
        at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288)
        at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:325)
        at javax.naming.InitialContext.lookup(InitialContext.java:392)
        at org.springframework.jndi.JndiTemplate$1.doInContext(JndiTemplate.java:154)
        at org.springframework.jndi.JndiTemplate.execute(JndiTemplate.java:87)
        at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:152)
        at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:178)
        at org.springframework.jndi.JndiLocatorSupport.lookup(JndiLocatorSupport.java:95)
        at org.springframework.jndi.JndiObjectLocator.lookup(JndiObjectLocator.java:105)
        at org.springframework.jndi.JndiObjectTargetSource.afterPropertiesSet(JndiObjectTargetSource.java:97)
        at org.springframework.jndi.JndiObjectFactoryBean$JndiObjectProxyFactory.createJndiObjectProxy(JndiObjectFactoryBean.java:285)
        at org.springframework.jndi.JndiObjectFactoryBean$JndiObjectProxyFactory.access$000(JndiObjectFactoryBean.java:274)
        at org.springframework.jndi.JndiObjectFactoryBean.afterPropertiesSet(JndiObjectFactoryBean.java:177)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1541)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1479)
        ... 15 more

Answer 1

如果您是在main之外的Tomcat外部运行此代码，则该代码将不起作用。 Tomcat为JNDI提供了初始上下文工厂。