【spring boot】FilterRegistrationBean介绍

前言

以往的javaee配置过滤器是在web.xml中配置的，如下代码

<filter>
     <filter-name>TestFilter</filter-name>
        <filter-class>com.cppba.filter.TestFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>TestFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <init-param>
       <param-name>paramName</param-name>
       <param-value>paramValue</param-value>
    </init-param>
</filter-mapping>

而spring boot 是没有这个配置的，怎么办？

解决办法

定义一个自定义的过滤器，类似原来的模式

package com.cppba.filter;

import javax.servlet.*;
import java.io.IOException;

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 {
        System.out.println("TestFilter");
    }

    @Override
    public void destroy() {

    }
}

主程序启动文件，增加

@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;
    }

总结：

Spring Boot针对Servlet、Filter等，有几种注册方法

1. 使用@WebFilter、@WebServlet、@WebListener注解来标识类
2. 使用FilterRegistrationBean、ServletRegistrationBean来对Filter、Servlet进行自定义注册
3. 使用@Bean来自动添加，添加后默认的过滤路径为 /*