在springboot添加過濾器有兩種方式：

1、通過創(chuàng)建FilterRegistrationBean的方式（建議使用此種方式，統(tǒng)一管理，且通過注解的方式若不是本地調試，如果在filter中需要增加cookie可能會存在寫不進前端情況）

2、通過注解@WebFilter的方式

通過創(chuàng)建FilterRegistrationBean的方式創(chuàng)建多個filter以及設置執(zhí)行順序：

1、創(chuàng)建兩個實現(xiàn)Filter接口的類TestFilter1 、TestFilter2

package com.aoxun.core.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;public class TestFilter1 implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException {} @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { chain.doFilter(request, response); } @Override public void destroy() {}}

package com.aoxun.core.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;public class TestFilter2 implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException {} @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { chain.doFilter(request, response); } @Override public void destroy() {}}

2、創(chuàng)建配置類

有多個filter就創(chuàng)建多個FilterRegistrationBean ，若需注明filter的執(zhí)行順序，可通過registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE - 1)配置，值越大，執(zhí)行順序越靠后

package com.aoxun.config.web;import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import com.aoxun.core.filter.TestFilter1;import com.aoxun.core.filter.TestFilter2;/** * filter配置 * @author zcj * */@Configurationpublic class FilterConfig2 { @Bean public FilterRegistrationBean companyUrlFilterRegister() { FilterRegistrationBean registration = new FilterRegistrationBean(); //注入過濾器 registration.setFilter(new TestFilter1()); //攔截規(guī)則 registration.addUrlPatterns('/*'); //過濾器名稱 registration.setName('testFilter1'); //過濾器順序 registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE); return registration; } @Bean public FilterRegistrationBean outLinkSecurityFilterRegister() { FilterRegistrationBean registration = new FilterRegistrationBean(); //注入過濾器 registration.setFilter(new TestFilter2()); //攔截規(guī)則 registration.addUrlPatterns('/*'); //過濾器名稱 registration.setName('testFilter2'); //過濾器順序 registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE - 1); return registration; } }

通過注解@WebFilter的方式

1、在啟動類上增加@ServletComponentScan注解，自動掃描帶有過濾器注解的包

2、在類上使用@WebFilter

package com.aoxun.core.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.annotation.WebFilter;import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.core.annotation.Order;@WebFilter(filterName='testFilter1',urlPatterns= {'/*'})public class TestFilter1 implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { // TODO Auto-generated method stub } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { chain.doFilter(request, response); } @Override public void destroy() { // TODO Auto-generated method stub }}

注：經(jīng)測試，@Order并不能實現(xiàn)過濾器排序功能，在springboot中注解的方式增加過濾器可通過修改過濾器文件名稱的方式排序，如上的過濾器TestFilter1在TestFilter2前。

補充知識：SpringBoot2.1.x，集成Filter過濾器的三種方式，包含OncePerRequestFilter方式

一）Filter過濾器簡介

主要作用：Filter使用戶可以改變一個request和修改一個response，它能夠在一個request到達servlet之前預處理request，也可以在response離開servlet時處理response。例如收集數(shù)據(jù)和包裝數(shù)據(jù)，并進行處理。

1、Filter是依賴Servlet容器的，如Tomcat。

2、Filter對所有的請求起作用，并是在sevlet之前處理。可以理解成過濾器中包含攔截器，當一個請求過來，先進行過濾器處理，再看程序是否受理該請求。過濾器執(zhí)行完后，程序中的攔截器再進行處理。

3、Filter只能處理HttpServletRequest和HttpServletResponse，底層是基于回調函數(shù)。

二）SpringBoot集成Filter過濾器

第一步：先創(chuàng)建一個maven項目，引入springboot的jar

<project xmlns='http://maven.apache.org/POM/4.0.0' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xsi:schemaLocation='http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd'> <modelVersion>4.0.0</modelVersion> <groupId>com.oysept</groupId> <artifactId>springboot_filter</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.4.RELEASE</version> <relativePath/> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <mainClass>com.oysept.FilterApplication</mainClass> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> </plugin> </plugins> </build></project>

添加一個application.yml配置文件，指定一個端口

server:

port: 8080

創(chuàng)建一個Demo測試接口

package com.oysept.controller; import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController; /** * Demo Controller * @author ouyangjun */@RestControllerpublic class DemoController { // 帶參GET請求: http://localhost:8080/demo/get/param?param=111222333444 @RequestMapping(value = '/demo/get/param', method = RequestMethod.GET) public String getParam(@RequestParam(value = 'param') String param) { System.out.println('=====>進入DemoController /demo/get/param'); return '/demo/get/param,' + param; }}

第二步：使用@WebFilter注解方式，實現(xiàn)Filter過濾器

當使用@WebFilter、@WebServlet、@WebListener等注解時, 需要在springboot啟動類中啟用@ServletComponentScan注解指定掃描包。

package com.oysept.filter; import java.io.IOException;import java.util.Enumeration; import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletContext;import javax.servlet.ServletException;import javax.servlet.annotation.WebFilter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse; import org.springframework.core.env.Environment;import org.springframework.web.filter.OncePerRequestFilter; /** * 過濾器, 過濾所有地址 * 方式一: 使用@WebFilter、@WebServlet、@WebListener等注解時, 需要在springboot啟動類中啟用@ServletComponentScan注解指定掃描包 * 方式二: 結合@WebFilter和@Component注解一起使用, 但可能會同時注入兩個bean, 可能會報錯, 可在application.yml配置中啟用同名Bean覆蓋: spring.main.allow-bean-definition-overriding=true * @author ouyangjun */@WebFilter(value = '/*', filterName = 'oauthFilter')public class OAuthFilter extends OncePerRequestFilter { @Override protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException { System.out.println('====>進入OAuthFilter doFilterInternal過濾器===='); System.out.println('請求地址: ' + request.getRequestURL()); System.out.println('GET請求參數(shù): '); Enumeration<String> parameters = request.getParameterNames(); String parameterName = ''; while (parameters.hasMoreElements()) { parameterName = parameters.nextElement(); System.out.println('參數(shù)名稱: ' + parameterName + ', 值: ' + request.getParameter(parameterName)); } // 工具類 //FilterConfig filterConfig = super.getFilterConfig(); //ServletContext servletContext = super.getServletContext(); //Environment environment = super.getEnvironment(); System.out.println('====>結束OAuthFilter doFilterInternal過濾器===='); filterChain.doFilter(request, response); }}

第三步：使用@Component注解方式，實現(xiàn)Filter過濾器

package com.oysept.filter; import java.io.IOException; import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Component; /** * 過濾器通過@Component注解注冊 * @author ouyangjun */@Componentpublic class PathFilter implements Filter { @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { // 轉換 HttpServletRequest request = (HttpServletRequest) servletRequest; HttpServletResponse response = (HttpServletResponse) servletResponse; System.out.println('====>進入PathFilter doFilter過濾器===='); System.out.println('====>結束PathFilter doFilter過濾器===='); filterChain.doFilter(request, response); }}

第四步：通過@Bean注解方式，實現(xiàn)Filter過濾器

@Configuration注解：相當于spring中的<beans>標簽

@Bean注解：相當于spring中<bean>標簽

package com.oysept.config; import java.io.IOException; import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse; import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration; /** * @Configuration注解: 相當于spring中的<beans>標簽 * @Bean注解: 相當于spring中<bean>標簽 * @author ouyangjun */@Configurationpublic class MyFilterConfig { @Bean public FilterRegistrationBean<MyFilter> testFilterRegistration() { FilterRegistrationBean<MyFilter> registration = new FilterRegistrationBean<>(); registration.setFilter(new MyFilter()); registration.addUrlPatterns('/*'); // 配置過濾路徑 registration.addInitParameter('paramName', 'paramValue'); // 添加初始值 registration.setName('myFilter'); // 設置filter名稱 registration.setOrder(1); // 請求中過濾器執(zhí)行的先后順序，值越小越先執(zhí)行 return registration; } // 實現(xiàn)一個過濾器 public class MyFilter implements Filter { @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { // 轉換 HttpServletRequest request = (HttpServletRequest) servletRequest; HttpServletResponse response = (HttpServletResponse) servletResponse; System.out.println('====>進入MyFilter doFilter過濾器===='); System.out.println('====>結束MyFilter doFilter過濾器===='); filterChain.doFilter(request, response); } }}

第五步：創(chuàng)建一個SpringBoot啟動類，并通過@ServletComponentScan注解指定掃描的Filter實現(xiàn)類

package com.oysept; import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.builder.SpringApplicationBuilder;import org.springframework.boot.web.servlet.ServletComponentScan; /** * @ServletComponentScan注解不指定掃描包時, 默認掃描當前包和子包 * @author ouyangjun */@SpringBootApplication@ServletComponentScan(basePackages = 'com.oysept.filter')public class FilterApplication { public static void main(String[] args) { new SpringApplicationBuilder(FilterApplication.class).run(args); }}

啟動main方法，在瀏覽器輸入地址：http://localhost:8080/demo/get/param?param=111222333444

在控制臺查看打印日志：

項目結構圖：

以上這篇解決springboot中配置過濾器以及可能出現(xiàn)的問題就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持好吧啦網(wǎng)。