SpringBoot_过滤器、Servlet、监听器

「爱情、让人受尽委屈。」 2021-10-06 03:08 411阅读 0赞

### SpringBoot\_过滤器、Servlet、监听器 ###

*  配置方式
 *   *  过滤器
     *  Servlet
     *  监听器
 *  注解方式
 *   *  过滤器
     *  监听器
     *  Servlet

# 配置方式 #

## 过滤器 ##

（1）自定义过滤器TestFilter

public class TestFilter implements Filter {
    	@Override
    	public void init(FilterConfig filterConfig) throws ServletException {
    	}
    	@Override
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException {
    		chain.doFilter(request, response);
    	}
    	@Override
    	public void destroy() {
    	}
    }

（2）配置

@Bean  
    public FilterRegistrationBean testFilterRegistration() {  
        FilterRegistrationBean registration = new FilterRegistrationBean();  
        registration.setFilter(new TestFilter());  
        registration.addUrlPatterns(”/*”);  
        registration.addInitParameter(”paramName”, “paramValue”);  
        registration.setName(”testFilter”);  
        registration.setOrder(1);  
        return registration;  
    }

## Servlet ##

（1）自定义

public class TestServlet extends HttpServlet {
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        	this.doPost(req, resp);
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            //...
        }
    }

（2）配置

@Bean
     public ServletRegistrationBean test2ServletRegistrationBean(){
          ServletRegistrationBean registration = new ServletRegistrationBean(new TestServlet());
          registration.setEnabled(true);
          registration.addUrlMappings("/servlet/test");
          return registration;
      }

## 监听器 ##

（1）自定义

public class TestListener implements ServletContextListener {
        @Override
        public void contextInitialized(ServletContextEvent sce) {
        }
        @Override
        public void contextDestroyed(ServletContextEvent sce) {
        }
    }

（2）配置

@Bean
      public ServletListenerRegistrationBean servletListenerRegistrationBean(){
        ServletListenerRegistrationBean servletListenerRegistrationBean = new ServletListenerRegistrationBean();
        servletListenerRegistrationBean.setListener(new TestListener());
        return servletListenerRegistrationBean;
      }

# 注解方式 #

入口类添加注解扫描：@ServletComponentScan

## 过滤器 ##

@WebFilter(urlPatterns = "/*", filterName = "testFilter")
      public class TestFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
        }
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
          filterChain.doFilter(servletRequest,servletResponse);
        }
        @Override
        public void destroy() {
        }
      }

## 监听器 ##

@WebListener
      public class TestListener implements ServletContextListener {
        @Override
        public void contextInitialized(ServletContextEvent servletContextEvent) {
        } 
        @Override
        public void contextDestroyed(ServletContextEvent servletContextEvent) {
        }
      }

## Servlet ##

@WebServlet(name = "testServlet",urlPatterns = "/test")
      public class TestServlet extends HttpServlet {
        @Override
        public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          this.doGet(req, resp);
        }
      }