Spring Boot中过滤器Filter具体实现

Spring Boot中过滤器Filter具体实现

1.通过 @Bean 注解来配置

实现Filter接口

package com.lay.spring.filter.demo01;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

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

/**
 * @Description:
 * @Author: lay
 * @Date: Created in 10:00 2019/1/14
 * @Modified By:IntelliJ IDEA
 */
@Component
public class MyFilter1 implements Filter {
    private static final Logger log= LoggerFactory.getLogger(MyFilter1.class);
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request= (HttpServletRequest) servletRequest;
        log.info("MyFilter1过滤器，url：{}",request.getRequestURI());
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

配置类

package com.lay.spring.filter.demo01;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.Filter;

/**
 * @Description: filter过滤器注册，如没有FilterRegistrationBean进行注册，则默认全部路径
 * @Author: lay
 * @Date: Created in 10:06 2019/1/14
 * @Modified By:IntelliJ IDEA
 */
@Configuration
@ServletComponentScan(basePackages = "com.lay.spring.filter.demo01")
public class MyFilterConfig {
    /**
     *
     * @Description: 采用spring注入的方式，myFilter1添加@Component注解
     * @param:
     * @param myFilter1
     * @return: org.springframework.boot.web.servlet.FilterRegistrationBean
     * @auther: lay
     * @date: 11:04 2019/1/14
     */
    @Bean
    public FilterRegistrationBean filterRegistrationBean(@Autowired Filter myFilter1){
        FilterRegistrationBean filterRegistrationBean=new FilterRegistrationBean();
        filterRegistrationBean.setFilter(myFilter1);//注册过滤器
        filterRegistrationBean.setOrder(0);//设置过滤器顺序
        filterRegistrationBean.addUrlPatterns("/filter/*");//匹配路径/filter/*
        return filterRegistrationBean;
    }


    /**
     *
     * @Description: 采用new方式进行注册
     * @param:
     * @return: org.springframework.boot.web.servlet.FilterRegistrationBean
     * @auther: lay
     * @date: 11:05 2019/1/14
     */
    @Bean
    public FilterRegistrationBean filterRegistrationBean2(){
        FilterRegistrationBean filterRegistrationBean=new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new MyFilter2());//注册过滤器
        filterRegistrationBean.setOrder(1);//设置过滤器顺序
        filterRegistrationBean.addUrlPatterns("/*");//匹配路径，全部
        return filterRegistrationBean;
    }
}

配置FilterRegistrationBean类来进行Filter过滤器的注册，addUrlPatterns方法匹配路径，如果有多个过滤器，可以使用setOrder方法进行顺序设置，数字越小优先级越高。

注：如果没有对FilterRegistrationBean进行配置注册，但是过滤器添加了@Component组件注解 ，同时启动类开启了@ServletComponentScan组件扫描，那么过滤器也会生效，匹配路径默认是/*全部。

2.通过 @WebFilter来配置

同样实现Filter接口

package com.lay.spring.filter.demo02;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

/**
 * @Description:
 * @Author: lay
 * @Date: Created in 10:49 2019/1/14
 * @Modified By:IntelliJ IDEA
 */
@WebFilter(urlPatterns = "/*",filterName = "my-filter3",displayName = "my-filter3")
public class MyFilter3 implements Filter {
    private static final Logger log= LoggerFactory.getLogger(MyFilter3.class);
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request= (HttpServletRequest) servletRequest;
        log.info("MyFilter3过滤器，url：{}",request.getRequestURI());
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

@WebFilter 的属性

属性名	类型	描述
filterName	String	指定过滤器的 name 属性，等价于
value	String[]	该属性等价于 urlPatterns 属性。但是两者不应该同时使用。
urlPatterns	String[]	指定一组过滤器的 URL 匹配模式。等价于 标签。
servletNames	String[]	指定过滤器将应用于哪些 Servlet。取值是 @WebServlet 中的 name 属性的取值，或者是 web.xml 中 的取值。
dispatcherTypes	DispatcherType	指定过滤器的转发模式。具体取值包括： ASYNC、ERROR、FORWARD、INCLUDE、REQUEST。
initParams	WebInitParam[]	指定一组过滤器初始化参数，等价于 标签。
asyncSupported	boolean	声明过滤器是否支持异步操作模式，等价于 标签。
description	String	该过滤器的描述信息，等价于 标签。
displayName	String	该过滤器的显示名，通常配合工具使用，等价于 标签。

然后在启动类上添加@ServletComponentScan注解使@WebFilter注解生效

package com.lay.spring.filter.demo02;

import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Configuration;

/**
 * @Description:
 * @Author: lay
 * @Date: Created in 11:16 2019/1/14
 * @Modified By:IntelliJ IDEA
 */
@Configuration
@ServletComponentScan(basePackages = "com.lay.spring.filter.demo02")
public class MyFilterConfig2 {
}

对于多个由@WebFilter注解注册的过滤器，其顺序是由类名决定的，根据A~Z进行排序。