创建 三个类
分别实现 Filter ServletContextListener HttpServlet
在springboot 启动类中@bean加入
2 ，实现 ServletContextIntializer接口
@SpringBootApplication
public class DemoApplication implements ServletContextInitializer{ public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
} @Override
public void onStartup(ServletContext servletContext) throws ServletException {
servletContext.addServlet("customServlet", new CustomServlet()).addMapping("/root");
servletContext.addFilter("customfilter", new CustomFilter())
.addMappingForServletNames(EnumSet.of(DispatcherType.REQUEST), true, "customServlet");
servletContext.addListener(new CustomListener());
}
}
3. 注解方式 主类加上@ServletComponentScan 给三个分别加上注解
@WebServlet(urlPatterns="/index", name="customServlet")
public class CustomServlet extends HttpServlet{
....
}@WebListener
public class CustomListener implements ServletContextListener{
....
}@WebFilter(urlPatterns="/*")
public class CustomFilter implements Filter{
...
}
4. 自定义注解 实现 主类上加上此注解
@Target(value = {ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(value = {FirstFilterConfiguration.class})
public @interface EnableFirstFilter {}
注册配置的bean（
FirstFilterConfiguration.class
）
public class FirstFilterConfiguration { public static final Integer ORDER = Integer.MIN_VALUE; @Bean
public FilterRegistrationBean firstFilter(){
// 默认不需要的但是为了拦截过滤固定的页面
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new FirstFilter());
registration.addUrlPatterns("/*");
registration.setName("firstFilter");
registration.setOrder(ORDER);
return registration;
}
}
public class FirstFilter implements Filter { @Override
public void destroy() { } @Override
public void doFilter(ServletRequest srst, ServletResponse srsp, FilterChain chain)
throws IOException, ServletException {
chain.doFilter(srst, srsp);
} @Override
public void init(FilterConfig arg0) throws ServletException { }}
@Configuration
@EnableWebMvc
public class WebMvcConfig extends WebMvcConfigurerAdapter{ @Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
//addResourceHandler 对外暴露的路径 addResourceLocations 对内暴露路径
registry.addResourceHandler("/aaserts/**").addResourceLocations("classpath:/assets/");
}
@Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/ws").setViewName("/ws");
registry.addViewController("/login").setViewName("/login");
registry.addViewController("/chat").setViewName("/chat");
} @Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(demoInterceptor());
} @Bean
public DemoInterceptor demoInterceptor() {
return new DemoInterceptor();
} //自定义拦截器
public class DemoInterceptor extends HandlerInterceptorAdapter{ @Override //请求发生前执行
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
return true;
} @Override // 请求发生后执行
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
ModelAndView modelAndView) throws Exception {
super.postHandle(request, response, handler, modelAndView);
}
}
}
拦截器
