一步一步学springboot （六）集成拦截器和过滤器及监听器

Bertha 。 2022-06-17 11:19 180阅读 0赞

一、实现过滤器Filter

1.新建类(**注意这个类上的注解**@Component,这个注解不可以用,如果不用,就得在springboot的那个标有@SpringBootApplication的类上加上@ServletComponentScan,总之是让spring扫描并管理这个类)

@WebFilter(filterName="myFilter",urlPatterns="/*") //@Component public class MyFilter implements Filter{ @Override public void destroy() { System.out.println("过滤器销毁。。。。。。。"); } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println("CustomFilter指定过滤器操作......"); //执行操作后必须doFilter chain.doFilter(request, response); } @Override public void init(FilterConfig arg0) throws ServletException { System.out.println("CustomFilter初始化......"); } }

二、监听器

**注意这个类上的注解**@Component,这个注解不可以用,如果不用,就得在springboot的那个标有@SpringBootApplication的类上加上@ServletComponentScan,总之是让spring扫描并管理这个类)

@WebListener //@Component public class MyListener implements ServletContextListener{ @Override public void contextDestroyed(ServletContextEvent arg0) { System.out.println("servletContext销毁......"); } @Override public void contextInitialized(ServletContextEvent arg0) { System.out.println("servletContext初始化......"); } }

三、拦截器

1.新建拦截器1

public class MyInterceptor1  implements HandlerInterceptor{
    	@Override  
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object,  
                Exception exception) throws Exception {  
            System.out.println("3.整个请求结束之后被调用......CustomInterceptor1......");  
        }  
      
        @Override  
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object, ModelAndView view)  
                throws Exception {  
            System.out.println("2. 请求处理之后进行调用，但是在视图被渲染之前......CustomInterceptor1......");  
        }  
      
        @Override  
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {  
            System.out.println("1. 在请求处理之前进行调用......CustomInterceptor1......");  
            return true;  
        } 
    	
    }

2.新建拦截器2(多个拦截器可以组成拦截器链)

public class MyInterceptor2 implements HandlerInterceptor{
    	@Override  
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object,  
                Exception exception) throws Exception {  
            System.out.println("3.整个请求结束之后被调用......CustomInterceptor2......");  
        }  
      
        @Override  
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object, ModelAndView view)  
                throws Exception {  
            System.out.println("2. 请求处理之后进行调用，但是在视图被渲染之前......CustomInterceptor2......");  
        }  
      
        @Override  
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {  
            System.out.println("1. 在请求处理之前进行调用......CustomInterceptor2......");  
            return true;  
        } 
    }

3.新建一个拦截器注册类

(注意：@Configuration @Component两个注解选一个就可以,也是让spring管理这个类

//@Configuration
    @Component
    public class MyInterceptorConfig extends WebMvcConfigurerAdapter{
    
    	@Override
    	public void addInterceptors(InterceptorRegistry registry) {
    		//众多的拦截器组成了一个拦截器链  
            /** 
             * 主要方法说明： 
             * addPathPatterns 用于添加拦截规则 
             * excludePathPatterns 用户排除拦截 
             */  
            registry.addInterceptor(new MyInterceptor1()).addPathPatterns("/*");  
            registry.addInterceptor(new MyInterceptor2()).addPathPatterns("/*");  
    		super.addInterceptors(registry);
    	}
    	
    }