SpringBoot学习总结（6）之整合Filter

淡淡的烟草味﹌ 2022-02-22 10:01 219阅读 0赞

# 一、环境 #

Maven 3.6.0
    IDEA IntelliJ IDEA 2017.2.6 x64
    JDK 1.8
    Spring Boot 1.5.4.RELEASE

二、pom.xml文件配置

<?xml version="1.0" encoding="UTF-8"?>
    <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>
    	<parent>
    		<groupId>org.springframework.boot</groupId>
    		<artifactId>spring-boot-starter-parent</artifactId>
    		<version>1.5.4.RELEASE</version>
    		<relativePath/> 
    	</parent>
    	<groupId>com.mqc</groupId>
    	<artifactId>springboot-mybatis</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<name>springboot-mybatis</name>
    	<description>Demo project for Spring Boot</description>
    
    	<properties>
    		<java.version>1.8</java.version>
    	</properties>
    
    	<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>
    			</plugin>
    		</plugins>
    	</build>
    
    </project>

# 三、整合方式一：通过注解扫描方式完成Filter组件的注册 #

编写Filter：

package com.mqc.filter;
    
    
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import java.io.IOException;
    
    /**
     * @author maoqichuan
     * @ClassName: annotationFilter
     * @description: 通过注解扫描方式完成Filter组件的注册
     * @date 2019-04-099:44
     * 以往我们要完成一个拦截器，首先就是要编写对应的拦截器类，其次就是要在web.xml中配置拦截器
     *<filter>
     * <filter-name>FirstFilter</filter-name>
     * <filter-class>com.bjsxt.filter.FirstFilter</filter-class>
     *</filter>
     *<filter-mapping>
     * <filter-name>FirstFilter</filter-name>
     * <url-pattern>/first</url-pattern>
     *</filter-mapping>
     **/
    @WebFilter(filterName = "AnnotationFilter",urlPatterns = "/annotationFilter")
    public class AnnotationFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.print("完成拦截器的初始化，在创建拦截器的时候自动调用");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            System.out.print("进入拦截器");
            //模拟预处理
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.print("退出拦截器");
        }
    
        @Override
        public void destroy() {
            System.out.print("在销毁拦截器的时候自动调用");
        }
    }

@WebFilter，标记这是一个拦截器类，FilterName属性表示这个拦截器的名字，urlPatterns为这个拦截器的拦截器请求路径。

编写对应的启动类，在上一篇博文中我已经介绍了SpringBoot如何整合Servlet，其中已经介绍了@ServletComponentScan的作用主要是什么，有需要的可以查看[https://blog.csdn.net/jokeMqc/article/details/89087714][https_blog.csdn.net_jokeMqc_article_details_89087714]，其实@ServletComponentScan在springBoot 启动时会扫描@WebFilter，并将该类实例化，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。

package com.mqc;
    
    
    import com.mqc.servlet.MyServlet;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletComponentScan;
    
    
    /**
     * @description: springboot整合Filter方式一：通过@ServletComponentScan注解扫描方式完成Filter组件的注册
     * @author maoqichuan
     * @date 2019-04-08 16:17
     */
    @SpringBootApplication
    @ServletComponentScan
    public class SpringbootMybatisApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(SpringbootMybatisApplication.class, args);
    	}
    
    
    }

调试，启动项目，可以看到我们写的Filter组件已经 被扫描到并且实例化了。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70][]

在浏览器输入：[http://localhost:8080/annotationFilter][http_localhost_8080_annotationFilter]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70 1][]

# 四、整合方式二：通过方法完成Filter 组件的注册 #

编写Filter。

package com.mqc.filter;
    
    import javax.servlet.*;
    import java.io.IOException;
    
    /**
     * @author maoqichuan
     * @ClassName: MethodFilter
     * @description: SpringBoot整合Filter方式二：通过方法注册Filter组件
     * @date 2019-04-0910:09
     **/
    public class MethodFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            System.out.println("完成MethodFilter组件的注册");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            System.out.println("进入--->>MethodFilter拦截器");
            try {
                // 模拟
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("退出--->>MethodFilter拦截器");
        }
    
        @Override
        public void destroy() {
    
        }
    }

编写启动类。

package com.mqc;
    
    
    import com.mqc.filter.MethodFilter;
    import com.mqc.servlet.MyServlet;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.FilterRegistrationBean;
    import org.springframework.context.annotation.Bean;
    
    
    /**
     * @description: springboot整合Filter方式二：通过方法完成Filter组件的注册
     * @author maoqichuan
     * @date 2019-04-08 16:17
     */
    @SpringBootApplication
    
    public class SpringbootMybatisApplication {
    
    	public static void main(String[] args) {
    		SpringApplication.run(SpringbootMybatisApplication.class, args);
    	}
    
    	/**
    	 * @description: 通过方法完成Filter组件的注册
    	 * @return FilterRegistrationBean
    	 * @throws
    	 * @author maoqichuan
    	 * @date 2019-04-09 10:14
    	 */
    	@Bean
    	public FilterRegistrationBean getFilterRegistrationBean(){
    		FilterRegistrationBean bean = new FilterRegistrationBean(new MethodFilter());
    
    		bean.addUrlPatterns("/methodFilter");
    		return bean;
    	}
    }

在浏览器中输入：[http://localhost:8080/methodFilter][http_localhost_8080_methodFilter]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70 2][]

到这里，SpringBoot整合Filter的两种方式到这里就已经是整合完毕了，大家有什么问题都可以私信我，让我们大家一起进步，一起努力，一起加油！

[https_blog.csdn.net_jokeMqc_article_details_89087714]: https://blog.csdn.net/jokeMqc/article/details/89087714
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70]: /images/20220222/e4904b421c74466b980bc5d98133ed60.png
[http_localhost_8080_annotationFilter]: http://localhost:8080/annotationFilter
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70 1]: /images/20220222/f8101f3c4e6845169cdf71638a04e8a4.png
[http_localhost_8080_methodFilter]: http://localhost:8080/methodFilter
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2pva2VNcWM_size_16_color_FFFFFF_t_70 2]: /images/20220222/4c7ae97585da41199ccf38c9398f44d8.png