spring boot过滤器FilterRegistrationBean

Dear 丶 2023-02-14 05:52 11阅读 0赞

有2种方式可以实现过滤器

1：通过FilterRegistrationBean实例注册

2：通过@WebFilter注解生效

这里选择第一种，因为第二种**不能设置过滤器之间的优先级**

为了演示优先级，这里创建2个测试过滤器类：**Test1Filter**、**Test2Filter**

通过实现**javax.servlet.Filter**接口，覆盖其doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)方法，决定拦截或放行

public class Test1Filter implements Filter {
    
        @Override
        public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
                throws IOException, ServletException {
            // TODO Auto-generated method stub
            HttpServletRequest request=(HttpServletRequest)arg0;
            System.out.println("自定义过滤器filter1触发,拦截url:"+request.getRequestURI());
            arg2.doFilter(arg0,arg1);
        }
    
    }

public class Test2Filter implements Filter {
    
        @Override
        public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
                throws IOException, ServletException {
            // TODO Auto-generated method stub
            HttpServletRequest request=(HttpServletRequest)arg0;
            System.out.println("自定义过滤器filter2触发,拦截url:"+request.getRequestURI());
            arg2.doFilter(arg0,arg1);
        }
    
    }

通过在springboot的configuration中配置不同的FilterRegistrationBean实例，来注册自定义过滤器

这里创建一个configuration类

import org.springframework.boot.web.servlet.FilterRegistrationBean;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import com.example.demo.filter.Test1Filter;
    import com.example.demo.filter.Test2Filter;
    
    @Configuration
    public class DemoConfiguration {
    
        @Bean
        public FilterRegistrationBean<Test1Filter> RegistTest1(){
            //通过FilterRegistrationBean实例设置优先级可以生效
            //通过@WebFilter无效
            FilterRegistrationBean<Test1Filter> bean = new FilterRegistrationBean<Test1Filter>();
            bean.setFilter(new Test1Filter());//注册自定义过滤器
            bean.setName("flilter1");//过滤器名称
            bean.addUrlPatterns("/*");//过滤所有路径
            bean.setOrder(1);//优先级，最顶级
            return bean;
        }
        @Bean
        public FilterRegistrationBean<Test2Filter> RegistTest2(){
            //通过FilterRegistrationBean实例设置优先级可以生效
            //通过@WebFilter无效
            FilterRegistrationBean<Test2Filter> bean = new FilterRegistrationBean<Test2Filter>();
            bean.setFilter(new Test2Filter());//注册自定义过滤器
            bean.setName("flilter2");//过滤器名称
            bean.addUrlPatterns("/test/*");//过滤所有路径
            bean.setOrder(6);//优先级，越低越优先
            return bean;
        }
    }

其中

1第一个bean拦截所有路径，而第二个只拦截/test/\*路径

2第一个bean优先级设置了1，而第二个设置了6，越低越优先，所以过滤器1应该在过滤器2前面拦截

运行springboot，访问/test/\*请求如下图，再访问/v请求如下图只拦截了过滤器1，而过滤器2路径不匹配

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3hpYW96aHUwMzAx_size_16_color_FFFFFF_t_70][]

如果把.addUrlPatterns();中拦截路径改成一样/test/\*，则所有请求，都会触发2个过滤器，而且过滤器1永远在最先拦截

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3hpYW96aHUwMzAx_size_16_color_FFFFFF_t_70 1][]

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