Tomcat with Spring

I have a 3-tier application hosted in Tomcat; web, service and DAO layers.

How do you integrate Tomcat and Spring? I need to make use of Spring's dependency injection, transaction management, etc.

I can only think开发者_运维知识库 of instantiating a ClassPathXmlApplicationContext but this way the ApplicationContext singleton instance is not visible across layers.

If you are creating web application you don't use ClassPathXmlApplicationContext. Instead of that you use features of web-container.

You define application context in web.xml.

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

For details take a look into documentation Convenient ApplicationContext instantiation for web applications.

If a bean needs instance of application context, use ApplicationContextAware interface.