Filter过滤器-蒲公英云

Filter过滤器

小咪咪 2023-07-06 09:49 13阅读 0赞

1.创建项目
在这里插入图片描述
2.点击Next

3.选择web

4.pom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 https://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>2.2.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.take</groupId>
    <artifactId>filter-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>filter-demo</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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

5.创建controller包，包下创建两个类：HelloController，WorldController

package com.take.filterdemo.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController { 
    @RequestMapping("hello")
    public String hello(){ 
        return "hello";
    }
}
package com.take.filterdemo.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class WorldController { 
    @RequestMapping("world")
    public String world(){ 
        return "world";
    }
}

6.添加application.yml，加入配置

server:
  port: 8080
spring:
  main:
    allow-bean-definition-overriding: true

7.创建filter包，包下创建HelloFilter类，并实现Fillter接口，注意是javax.servlet.*;下的包

只拦截了/hello的资源，并没有拦截/world资源

package com.take.filterdemo.filter;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/** * urlPatterns: 拦截的路径，可以写多个，如 @WebFilter(urlPatterns = {"/hello","/world"},filterName = "helloFilter") */
@Component
@WebFilter(urlPatterns = "/hello",filterName = "helloFilter")
public class HelloFilter implements Filter { 
    @Override
    public void init(FilterConfig filterConfig) throws ServletException { 
    }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { 
        HttpServletRequest request=(HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //逻辑省略。。。
// filterChain.doFilter(servletRequest,servletResponse);//放行
    }
    @Override
    public void destroy() { 
    }
}

8.在启动类上加上注解@ServletComponentScan，会把过滤器扫描到spring中

package com.take.filterdemo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
@SpringBootApplication
@ServletComponentScan
public class FilterDemoApplication { 
    public static void main(String[] args) { 
        SpringApplication.run(FilterDemoApplication.class, args);
    }
}