WEB中多个过滤器的执行顺序

冷不防 2023-06-08 06:34 82阅读 0赞

**首先配置两个过滤器：**

**过滤器1：**

package com.bjsxt.filter;
    
    import javax.servlet.*;
    import java.io.IOException;
    
    public class Filter1 implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.println("init1");
        }
    
        @Override
        public void destroy() {
            System.out.println("destroy1");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            System.out.println("do1");
            filterChain.doFilter(servletRequest,servletResponse);
            System.out.println("do after1");
        }
    }

**过滤器二：**

package com.bjsxt.filter;
    
    import javax.servlet.*;
    import java.io.IOException;
    
    public class Filter2 implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.println("in2");
        }
    
        @Override
        public void destroy() {
            System.out.println("des2");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            System.out.println("do2");
            filterChain.doFilter(servletRequest,servletResponse);
            System.out.println("do after2");
        }
    }

**然后再web.xml中进行配置：（这里需要注意过滤器的执行顺序按照xml的配置顺序来执行的）**

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
             version="4.0">
        <servlet>
            <servlet-name>dis</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:MVC.xml</param-value>
            </init-param>
        </servlet>
        <servlet-mapping>
            <servlet-name>dis</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
        <context-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext-*.xml</param-value>
        </context-param>
    
        <listener>
            <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
        </listener>
    
        <filter>
            <filter-name>f</filter-name>
            <filter-class>com.bjsxt.filter.Filter1</filter-class>
        </filter>
        <filter-mapping>
            <filter-name>f</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    
        <filter>
            <filter-name>f2</filter-name>
            <filter-class>com.bjsxt.filter.Filter2</filter-class>
        </filter>
        <filter-mapping>
            <filter-name>f2</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    
    </web-app>

执行顺序如图所示：

![20191017100956442.png][]

![20191017101021593.png][]

[20191017100956442.png]: /images/20230531/057c6db723c440f1baf29f8e4f9ca156.png
[20191017101021593.png]: /images/20230531/4bad137b1a6a4a29b690331ddc40c6f6.png