springboot实战笔记(六 )----springboot整合Filter

素颜马尾好姑娘i 2022-01-26 07:37 246阅读 0赞

### 一 前言 ###

在以往的web.xml方式中，我们是通过以下形式进行配置的：

<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>

但是在springboot整合Filter可以通过以下的两种方式，跟servlet很相似

*  通过注解扫描完成 Filter 组件的注册，
 *  通过方法完成 Filter 组件的注册

pom.xml文件

<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>1.5.10.RELEASE</version>
      </parent>
      <groupId>com.bjsxt</groupId>
      <artifactId>03-spring-boot-filter</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      
      
      <properties>
      	<java.version>1.7</java.version>
      </properties>
      
      <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>
    </project>

### 二 注解扫描方式 ###

1.编写Filter类

package com.bjsxt.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;
    
    /**
     *SpringBoot整合Filter 方式一
     */
    //@WebFilter(filterName="FirstFilter",urlPatterns={"*.do","*.jsp"})
    @WebFilter(filterName="FirstFilter",urlPatterns="/first")
    public class FirstFilter implements Filter {
    
    	@Override
    	public void destroy() {
    		// TODO Auto-generated method stub
    
    	}
    	@Override
    	public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
    			throws IOException, ServletException {
    		System.out.println("进入Filter");
    		arg2.doFilter(arg0, arg1);
    		System.out.println("离开Filter");
    	}
    
    	@Override
    	public void init(FilterConfig arg0) throws ServletException {
    		// TODO Auto-generated method stub
    	}
    }

2.编写启动类

package com.bjsxt;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletComponentScan;
    
    /**
     *SpringBoot整合Filter 方式一
     *
     */
    @SpringBootApplication
    @ServletComponentScan
    public class App {
    
    	public static void main(String[] args) {
    		SpringApplication.run(App.class, args);
    
    	}
    
    }

### 三 方法方式 ###

1，编写Filter类

package com.bjsxt.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;
    /**
     * 
     *SpringBoot整合Filter 方式二
     *
     */
    public class SecondFilter implements Filter {
    	@Override
    	public void destroy() {
    		// TODO Auto-generated method stub
    	}
    	@Override
    	public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
    			throws IOException, ServletException {
    		System.out.println("进入SecondFilter");
    		arg2.doFilter(arg0, arg1);
    		System.out.println("离开SecondFilter");
    	}
    
    	@Override
    	public void init(FilterConfig arg0) throws ServletException {
    		// TODO Auto-generated method stub
    	}
    }

2.编写启动类

package com.bjsxt;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.FilterRegistrationBean;
    import org.springframework.boot.web.servlet.ServletRegistrationBean;
    import org.springframework.context.annotation.Bean;
    
    import com.bjsxt.filter.SecondFilter;
    import com.bjsxt.servlet.SecondServlet;
    
    /**
     * SpringBoot整合Filter方式二
     *
     *
     */
    @SpringBootApplication
    public class App2 {
    
    	public static void main(String[] args) {
    		SpringApplication.run(App2.class, args);
    	}
    	
    	/**
    	 * 注册Filter
    	 */
    	@Bean
    	public FilterRegistrationBean getFilterRegistrationBean(){
    		FilterRegistrationBean bean = new FilterRegistrationBean(new SecondFilter());
    		//bean.addUrlPatterns(new String[]{"*.do","*.jsp"});
    		bean.addUrlPatterns("/second");
    		return bean;
    	}
    }