spring boot過濾器FilterRegistrationBean

有2種方式可以實現過濾器

1：通過FilterRegistrationBean實例註冊

2：通過@WebFilter註解生效

這裏選擇第一種，因爲第二種不能設置過濾器之間的優先級

爲了演示優先級，這裏創建2個測試過濾器類：Test1Filter、Test2Filter

通過實現javax.servlet.Filter接口，覆蓋其doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)方法，決定攔截或放行

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("自定義過濾器filter1觸發,攔截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("自定義過濾器filter2觸發,攔截url:"+request.getRequestURI());
        arg2.doFilter(arg0,arg1);
    }

}

通過在springboot的configuration中配置不同的FilterRegistrationBean實例，來註冊自定義過濾器

這裏創建一個configuration類

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(){
        //通過FilterRegistrationBean實例設置優先級可以生效
        //通過@WebFilter無效
        FilterRegistrationBean<Test1Filter> bean = new FilterRegistrationBean<Test1Filter>();
        bean.setFilter(new Test1Filter());//註冊自定義過濾器
        bean.setName("flilter1");//過濾器名稱
        bean.addUrlPatterns("/*");//過濾所有路徑
        bean.setOrder(1);//優先級，最頂級
        return bean;
    }
    @Bean
    public FilterRegistrationBean<Test2Filter> RegistTest2(){
        //通過FilterRegistrationBean實例設置優先級可以生效
        //通過@WebFilter無效
        FilterRegistrationBean<Test2Filter> bean = new FilterRegistrationBean<Test2Filter>();
        bean.setFilter(new Test2Filter());//註冊自定義過濾器
        bean.setName("flilter2");//過濾器名稱
        bean.addUrlPatterns("/test/*");//過濾所有路徑
        bean.setOrder(6);//優先級，越低越優先
        return bean;
    }
}

其中

1第一個bean攔截所有路徑，而第二個只攔截/test/*路徑

2第一個bean優先級設置了1，而第二個設置了6，越低越優先，所以過濾器1應該在過濾器2前面攔截

運行springboot，訪問/test/*請求如下圖，再訪問/v請求如下圖只攔截了過濾器1，而過濾器2路徑不匹配

如果把.addUrlPatterns();中攔截路徑改成一樣/test/*，則所有請求，都會觸發2個過濾器，而且過濾器1永遠在最先攔截