定義一個filter, 實現ApplicationContextAware接口:
public class CacheFilter implements Filter, ApplicationContextAware {
private static ApplicationContext ctx; // 必須聲明為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變量中
}
然後,在spring配置文件中配置該filter,使之成為容器管理的bean:
<beans:bean id="cacheFilter" class="com.fh.taolijie.servlet.CacheFilter" />
最後,在web.xml中聲明過濾器:
<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>
這時,我們就可以在doFilter()方法中直接通過ApplicationContext檢索需要的bean了:
StringRedisTemplate redis = (StringRedisTemplate)ctx.getBean("redisTemplate");