springboot过滤器和拦截器使用

桃扇骨 2022-05-16 07:00 244阅读 0赞

## 过滤器: ##

过滤器依赖servlet容器，在spring boot中添加自己的Servlet有两种方法，代码注册Servlet和注解自动注册（Filter和Listener也是如此）。   
一、代码注册通过ServletRegistrationBean、 FilterRegistrationBean 和 ServletListenerRegistrationBean 获得控制。   
也可以通过实现 ServletContextInitializer 接口直接注册。

二、在 SpringBootApplication 上使用@ServletComponentScan 注解后，Servlet、Filter、Listener 可以直接通过 @WebServlet、@WebFilter、@WebListener 注解自动注册，无需其他代码。

**基于注解注册：（编写自定义过滤器然后在springboot主类加上@ServletComponentScan）**

package com.yc.filter;
    
    import com.yc.util.SessionAttributeKey;
    
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    
    @WebFilter(filterName = "LoginFilter", urlPatterns = {"/*"})
    public class LoginFilter implements Filter {
    
        private static String mainPage = "/";
    
        /**
         * 封装，不需要过滤的list列表
         */
        protected static List<Pattern> patterns = new ArrayList<Pattern>();
    
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            patterns.add(Pattern.compile("/"));
            patterns.add(Pattern.compile("/swagger-ui.html"));
            patterns.add(Pattern.compile("/login"));
            patterns.add(Pattern.compile("/toyc.action"));
            patterns.add(Pattern.compile("back/user/login.action"));
            patterns.add(Pattern.compile("front/index.action"));
            patterns.add(Pattern.compile("front/content.action"));
            patterns.add(Pattern.compile("front/login.action"));
            patterns.add(Pattern.compile("front/reg.action"));
            patterns.add(Pattern.compile("front/fatie.action"));
            patterns.add(Pattern.compile("front/bankuai.action"));
            patterns.add(Pattern.compile("back/huifu/findAllHuifu.action"));
            patterns.add(Pattern.compile("back/huifu/addHuifu.action"));
            patterns.add(Pattern.compile("back/bankuai/findAllBankuai.action"));
            patterns.add(Pattern.compile("back/tiezi/findAllTiezi.action"));
            patterns.add(Pattern.compile("ueditor/third-party/zeroclipboard/ZeroClipboard.swf"));
            patterns.add(Pattern.compile("ueditor/dialogs/emotion/emotion.html"));
            patterns.add(Pattern.compile("ueditor/dialogs/image/image.html"));
            patterns.add(Pattern.compile("back/user/sendEmail.action"));
            patterns.add(Pattern.compile("back/user/regUser.action"));
            patterns.add(Pattern.compile("back/user/logins.action"));
            patterns.add(Pattern.compile(".*\\.[(js)||(css)||(png)||(ico)||(jpg)||(gif)||(xls)||(pdf)||(doc)]+"));
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {
            HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            String url = httpRequest.getRequestURI().substring(httpRequest.getContextPath().length());
            if (url.startsWith("/") && url.length() > 1) {
                url = url.substring(1);
            }
    
            if (isInclude(url)) {
                chain.doFilter(httpRequest, httpResponse);
                return;
            } else {
                HttpSession session = httpRequest.getSession();
                if (session.getAttribute(SessionAttributeKey.LOGIN_ADMIN) != null) {
                    // session存在
                    chain.doFilter(httpRequest, httpResponse);
                    return;
                } else {
    
                    // session不存在 准备跳转失败
                    String path = httpRequest.getScheme() + "://" + httpRequest.getServerName() + ":" + httpRequest.getServerPort() + httpRequest.getContextPath();
                    httpResponse.getWriter().print("<script>location.href='" + path + mainPage + "'</script>");
                    return;
                }
            }
    
        }
    
        @Override
        public void destroy() {
    
        }
    
        /**
         * 是否需要过滤
         *
         * @param url
         * @return
         */
        private boolean isInclude(String url) {
            for (Pattern pattern : patterns) {
                Matcher matcher = pattern.matcher(url);
                if (matcher.matches()) {
                    return true;
                }
            }
            return false;
        }
    
    }

**基于代码注册:**

import org.slf4j.LoggerFactory;
    import javax.servlet.*;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    /**
     * Created by mazhenhua on 2016/12/27.
     *
     * 过滤器
     */
    public class SessionFilter implements Filter {
        private static final org.slf4j.Logger logger = LoggerFactory.getLogger(SessionFilter.class);
    
    
        /**
         * 封装，不需要过滤的list列表
         */
        protected static List<Pattern> patterns = new ArrayList<Pattern>();
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {
            HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
            HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;
            logger.info("aaaaaaaaaa");
            String url = httpRequest.getRequestURI().substring(httpRequest.getContextPath().length());
            if (url.startsWith("/") && url.length() > 1) {
                url = url.substring(1);
            }
    
            if (isInclude(url)){
                chain.doFilter(httpRequest, httpResponse);
                return;
            } else {
                HttpSession session = httpRequest.getSession();
                if (session.getAttribute("") != null){
                    // session存在
                    chain.doFilter(httpRequest, httpResponse);
                    return;
                } else {
                    // session不存在 准备跳转失败
                    /* RequestDispatcher dispatcher = request.getRequestDispatcher(path);
                        dispatcher.forward(request, response);*/
                    chain.doFilter(httpRequest, httpResponse);
                    return;
                }
            }
        }
    
        @Override
        public void destroy() {
    
        }
    
    
        /**
         * 是否需要过滤
         * @param url
         * @return
         */
        private boolean isInclude(String url) {
            for (Pattern pattern : patterns) {
                Matcher matcher = pattern.matcher(url);
                if (matcher.matches()) {
                    return true;
                }
            }
            return false;
        }
    }

/**
         * 配置过滤器   如果有多个可以通过order属性，来设置执行顺序
         * @return
         */
        @Bean
        public FilterRegistrationBean someFilterRegistration() {
            FilterRegistrationBean registration = new FilterRegistrationBean();
            registration.setFilter(sessionFilter());
            registration.addUrlPatterns("/*");
            registration.addInitParameter("paramName", "paramValue");
            registration.setName("sessionFilter");
            return registration;
        }
    
        /**
         * 创建一个bean
         * @return
         */
        @Bean(name = "sessionFilter")
        public Filter sessionFilter() {
            return new SessionFilter();
        }

## 拦截器： ##

spring拦截器分两种一种是HandlerInterceptor，一种MethodInterceptor，这里介绍前一种：

@Component
    public class LoginInterceptor implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
            return false;
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    
        }
    }

@Configuration
    public class LoginConfigurtion extends WebMvcConfigurerAdapter{
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
            registry.addInterceptor(new LoginInterceptor())
                    .addPathPatterns("/*")
                    .excludePathPatterns("/user/login");
        }
    }

不过springboot2.0和spring5.0就废弃了WebMvcConfigurerAdapter，目前解决方法有两种：

1. 直接实现WebMvcConfigurer（官方推荐）

2. 继承WebMvcConfiguractionSupport

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