Spring：在bean中获取ServletContext

通过ServletContext可以获取到有关当前程序的很多信息，比如web目录的绝对路径等

Spring中有一个很有用的接口，使得bean能够很方便的引用ServletContext，这个接口就是：ServletContextAware

public interface ServletContextAware extends Aware {/** * Set the ServletContext that this object runs in. * <p>Invoked after population of normal bean properties but before an init * callback like InitializingBean's <code>afterPropertiesSet</code> or a * custom init-method. Invoked after ApplicationContextAware's * <code>setApplicationContext</code>. * @param servletContext ServletContext object to be used by this object * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet * @see org.springframework.context.ApplicationContextAware#setApplicationContext */void setServletContext(ServletContext servletContext);}

当系统中有ServletContext被初始化时，Spring框架会调用实现了ServletContextAware接口实例的setServletContext()方法，你可以在这个方法里面做任何操作。

我实现这个接口的初衷就是为了解决获取web目录的绝对路径，列取某个目录下的文件信息：

@Servicepublic class PicsManagerImpl implements PicsManager, ServletContextAware {    private static ServletContext servletContext;    private static String picsRealPath;    @Override    public void setServletContext(ServletContext servletContext) {        PicsManagerImpl.servletContext = servletContext;        PicsManagerImpl.picsRealPath = servletContext                .getRealPath("WEB-INF/pics") + File.separator;    }}