springBoot2.0实现过滤器，拦截器

傷城~ 2022-03-10 14:50 199阅读 0赞

# 说明 #

楼主使用springBoot2.0搭建测试项目

pom.xml如下：

<?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>2.1.3.RELEASE</version>
 		<relativePath/> 
 	</parent>
 	<groupId>com.example</groupId>
 	<artifactId>springDemo</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 	<name>springDemo</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-aop</artifactId>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
 
 		<dependency>
 			<groupId>org.projectlombok</groupId>
 			<artifactId>lombok</artifactId>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
 
 	<build>
 		<plugins>
 			<plugin>
 				<groupId>org.springframework.boot</groupId>
 				<artifactId>spring-boot-maven-plugin</artifactId>
 			</plugin>
 		</plugins>
 	</build>
 
 </project>

只有一个controller

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h6YXVfaXRkb2c_size_16_color_FFFFFF_t_70][]

##  拦截器 ##

第一步：

新建一个拦截器实现HandlerInterceptor接口

/** 
 * Project Name:springDemo 
 * File Name:MyInterceptor.java 
 * Package Name:com.springDemo.interceptor 
 * Date:2019年3月11日下午2:17:18 
 * @author yym 
 * 
 */
 
 package com.springDemo.interceptor;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.web.servlet.HandlerInterceptor;
 import org.springframework.web.servlet.ModelAndView;
 
 /**
 * ClassName: MyInterceptor 
 * Function: TODO ADD FUNCTION. 
 * Reason: TODO ADD REASON(可选). 
 * date: 2019年3月11日 下午2:17:18 
 * 
 * @author yym
 * @version
 * @since JDK 1.8
 */
 public class MyInterceptor implements HandlerInterceptor {
 
 	/**
 	 * TODO 简单描述该方法的实现功能（可选）.
 	 * 
 	 * @see org.springframework.web.servlet.HandlerInterceptor#preHandle(javax.servlet.http.HttpServletRequest,
 	 * javax.servlet.http.HttpServletResponse, java.lang.Object)
 	 */
 
 	@Override
 	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
 			throws Exception {
 		System.out.println("自定义MyInterceptor的------------------preHandle执行.....");
 		return HandlerInterceptor.super.preHandle(request, response, handler);
 	}
 
 	/**
 	 * TODO 简单描述该方法的实现功能（可选）.
 	 * 
 	 * @see org.springframework.web.servlet.HandlerInterceptor#postHandle(javax.servlet.http.HttpServletRequest,
 	 * javax.servlet.http.HttpServletResponse, java.lang.Object,
 	 * org.springframework.web.servlet.ModelAndView)
 	 */
 
 	@Override
 	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
 			ModelAndView modelAndView) throws Exception {
 		// TODO Auto-generated method stub
 		System.out.println("自定义MyInterceptor的------------------postHandle执行.....");
 		HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
 	}
 
 	/**
 	 * TODO 简单描述该方法的实现功能（可选）.
 	 * 
 	 * @see org.springframework.web.servlet.HandlerInterceptor#afterCompletion(javax.servlet.http.HttpServletRequest,
 	 * javax.servlet.http.HttpServletResponse, java.lang.Object,
 	 * java.lang.Exception)
 	 */
 
 	@Override
 	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
 			throws Exception {
 		// TODO Auto-generated method stub
 		System.out.println("自定义MyInterceptor的------------------afterCompletion执行.....");
 		HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
 	}
 
 }

第二步：

用java的方式新建一个配置类

继承***WebMvcConfigurationSupport***

重写*** addInterceptors(InterceptorRegistry registry) ***

来管理拦截器

/** 
 * Project Name:springDemo 
 * File Name:WebMvcConfig.java 
 * Package Name:com.springDemo.config 
 * Date:2019年3月11日下午2:21:50 
 * @author yym 
 * 
 */
 
 package com.springDemo.config;
 
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
 
 import com.springDemo.interceptor.MyInterceptor;
 
 /**
 * ClassName: WebMvcConfig 
 * Function: TODO ADD FUNCTION. 
 * Reason: TODO ADD REASON(可选). 
 * date: 2019年3月11日 下午2:21:50 
 * 
 * @author yym
 * @version
 * @since JDK 1.8
 */
 @Configuration
 public class WebMvcConfig extends WebMvcConfigurationSupport {
 
 	/**
 	 * TODO 简单描述该方法的实现功能（可选）.
 	 * 
 	 * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport#addInterceptors(org.springframework.web.servlet.config.annotation.InterceptorRegistry)
 	 */
 
 	@Override
 	protected void addInterceptors(InterceptorRegistry registry) {
 		super.addInterceptors(registry);
 		registry.addInterceptor(new MyInterceptor());
 		
 	}
 
 }

测试如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h6YXVfaXRkb2c_size_16_color_FFFFFF_t_70 1][]

### 过滤器 ###

第一步：

新建一个MyFilter实现Filter

@Component
    @WebFilter(urlPatterns = "/**", filterName = "myFilter")
    public class MyFilter implements Filter {
    
    	/**
    	 * TODO 简单描述该方法的实现功能（可选）.
    	 * 
    	 * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
    	 *      javax.servlet.ServletResponse, javax.servlet.FilterChain)
    	 */
    
    	@Override
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    			throws IOException, ServletException {
    		System.out.println("MyFilter执行了");
    		chain.doFilter(request, response);
    
    	}
    
    }

第二步

配置filter

方式一

通过@WebFilter(urlPatterns = "/\*\*", filterName = "myFilter")

结果如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h6YXVfaXRkb2c_size_16_color_FFFFFF_t_70 2][]

方式二：

通过配置

@Configuration
 public class FilterConfig {
 	@Bean
 	public FilterRegistrationBean<MyFilter> testFilterRegistration() {
 		FilterRegistrationBean<MyFilter> registration = new FilterRegistrationBean<MyFilter>();
 		registration.setFilter(new MyFilter());
 		registration.addUrlPatterns("/*"); //
 		registration.setOrder(1);
 		return registration;
 	}
 
 }

注意方式2 的拦截规则和方式1不同

### 过滤器和拦截器的区别： ###

1.  　　拦截器是基于java的反射机制的，而过滤器是基于函数回调。
2.  　　拦截器不依赖与servlet容器，过滤器依赖与servlet容器。
3.  　　拦截器只能对action请求起作用，而过滤器则可以对几乎所有的请求起作用。
4.  　　拦截器可以访问action上下文、值栈里的对象，而过滤器不能访问。
5.  　　在action的生命周期中，拦截器可以多次被调用，而过滤器只能在容器初始化时被调用一次。
6.  　　拦截器可以获取IOC容器中的各个bean，而过滤器就不行，这点很重要，在拦截器里注入一个service，可以调用业务逻辑。

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2h6YXVfaXRkb2c_size_16_color_FFFFFF_t_70 2]: /images/20220310/2f155af2289148c5aa53ac49a957cbb0.png