定义一个filter, 实现ApplicationContextAware接口：
public class CacheFilter implements Filter, ApplicationContextAware {
private static ApplicationContext ctx; // 必须声明为static
@Override
public void init(FilterConfig config) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
filterChain.doFilter(servletRequest, servletResponse);
}
@Override
public void destroy() {
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
CacheFilter.ctx = applicationContext; // 保存spring容器到static变量中
}
然后，在spring配置文件中配置该filter，使之成为容器管理的bean:
<beans:bean />
最后，在web.xml中声明过滤器：
<filter>
<filter-name>Cache Filter</filter-name>
<filter-class>com.fh.taolijie.servlet.CacheFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>Cache Filter</filter-name>
<servlet-name>appServlet</servlet-name>
</filter-mapping>
这时，我们就可以在doFilter()方法中直接通过ApplicationContext检索需要的bean了：
StringRedisTemplate redis = (StringRedisTemplate)ctx.getBean("redisTemplate");