基于SpringBoot,SSM的Filter,Servlet,Listener,Interceptor的实现

整理一下,关于Servlet Listener 和Filter 有两种注册方式:

    1.基于注解

    2.Java Config的形式

PS:本人的Spring版本是5.x 非4.x

先说第一种形式:SpringBoot:  注意要在启动类上加上@ServletComponentScan注解 不然Servlet,Listener,Filter都不会启作用

    Servlet:

@WebServlet(name="servletTest1",urlPatterns="/servlet/test")
public class ServletTest1 extends HttpServlet
{
    private static final long serialVersionUID = -5310239197651527329L;
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        System.out.println("this is my servlet get way");
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
    {
        System.out.println("this is my servlet post way");
    }
}

    Listener:

@WebListener
public class ListenerTest1 implements ServletContextListener
{
    @Override
    public void contextDestroyed(ServletContextEvent arg0)
    {
        System.out.println("dddddd");
    }

    @Override
    public void contextInitialized(ServletContextEvent arg0)
    {
        System.out.println("this is listener,configured by annotation");

    }
}

   Filter:

@WebFilter(urlPatterns="/annotation/test1")
public class AnnotationFilterTest1 implements Filter
{
    @Override
    public void init(FilterConfig filterConfig) throws ServletException
    {
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException
    {
        System.out.println("this is filter by annotation");
        chain.doFilter(request, response);
    }
    @Override
    public void destroy()
    {
    }
}

Interceptor:

    SpringBoot不提供基于注解的形式注册Interceptor,所以只能手动注册啦

 

public class MyInterceptorTest1 implements HandlerInterceptor
{
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
    {
        System.out.println("在controller之前执行,只有这个返回true,postHandler才会执行");
        return HandlerInterceptor.super.preHandle(request, response, handler);
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception
    {
        System.out.println("controller之后,在渲染页面之前执行");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception
    {
        System.out.println("渲染页面之后执行");
    }
}
@Configuration
public class InterceptroConfiguration implements WebMvcConfigurer
{
    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        registry.addInterceptor(new MyInterceptorTest1()).addPathPatterns("/interceptor/*");
    }

}

我的版本是Spring5.x WebMvcConfigurer 提供了默认的接口的实现方式,所以只需要implements即可,5.x以下的版本需要extends WebMvcConfigurerAdapter 即可

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------第二种形式:基于Java Config

Servlet: Servlet类的写法:只需要继承HttpServlet即可

    

        @Bean
    public ServletRegistrationBean servletRegistrationBean()
    {
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean<>();
        servletRegistrationBean.setServlet(new ServletTest1());
        servletRegistrationBean.addUrlMappings("/servlet/test2");
        return servletRegistrationBean;
    }
    @Bean
    public ServletRegistrationBean servletRegistrationBean3()
    {
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean<>();
        servletRegistrationBean.setServlet(new ServletJavaConfigTest3());
        servletRegistrationBean.addUrlMappings("/servlet/test3");
        return servletRegistrationBean;
    }

Filter:实现了Filter接口即可,Filter之间的执行顺序通过order来实现,order的值越低越先执行

@Bean
public FilterRegistrationBean filterRegistrationBean1()
{
    FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean<>();
    filterRegistrationBean.setFilter(new FilterJavaConfigTest2());
    filterRegistrationBean.setUrlPatterns(Arrays.asList("/filter/test/*"));
    filterRegistrationBean.setOrder(1);
    return filterRegistrationBean;
}

@Bean
public FilterRegistrationBean filterRegistrationBean2()
{
    FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean<>();
    filterRegistrationBean.setFilter(new FilterJavaConfigTest3());
    filterRegistrationBean.setUrlPatterns(Arrays.asList("/filter/test/*"));
    filterRegistrationBean.setOrder(2);
    return filterRegistrationBean;
}

Listener: 根据需求实现不同的listener接口即可

@Bean
public ServletListenerRegistrationBean servletListenerRegistrationBean()
{
    ServletListenerRegistrationBean servletListenerRegistrationBean = new ServletListenerRegistrationBean<>();
    servletListenerRegistrationBean.setListener(new ListenerTest1());
    return servletListenerRegistrationBean;
}

Interceptor:与上面写的那种Interceptor相同

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------至于常见的SSM项目,重点是在web.xml,除了Interceptor 

PS:因为本人搭建SSM项目更喜欢于采用JavaConfig的形式,怕麻烦,哈哈(不不不,该说SSM项目搭建有点烦),所以此处直接随意新建了个web.xml来代替

Servlet:

    test3
    class>com.test.servlet.ServletJavaConfigTest3class>



    test3
    /*

Listener:

    

        class>com.test.listener.ListenerTest1class>

Filter:

    ss
    class>com.test.filter.AnnotationFilterTest1class>


    ss
    /*

Interceptor是特殊的存在,他是基于SpringMVC的,所以要在Spring的配置文件中配置,但是本人更喜欢JavaConfig的形式,所以更喜欢:

@Configuration
public class InterceptroConfiguration implements WebMvcConfigurer
{
    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        registry.addInterceptor(new MyInterceptorTest1()).addPathPatterns("/interceptor/*");
        registry.addInterceptor(new MyInterceptorTest2()).addPathPatterns("/interceptor/33");
    }
}

而非: (随个人喜好!!!!!!!!!!!!!!!!!!!!!!!!!)

          "/admin"/>
          class="com.test.blog.Interceptor.SecurityInterceptor"/>


          "/admin/**"/>
          class="com.test.blog.Interceptor.SecurityInterceptor"/>