SpringBoot整合Filter的两种方式

蔚落 2022-01-10 01:19 395阅读 0赞

1.创建maven项目，导入springboot的maven依赖

pom.xml

<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>1.5.2.RELEASE</version>
      
      
      </parent>
    
      <groupId>per.czt.03-spring-boot-filter</groupId>
      <artifactId>03-spring-boot-filter</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>jar</packaging>
    
      <name>03-spring-boot-filter</name>
      <url>http://maven.apache.org</url>
    
     <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.7</java.version>
      </properties>
    
      <dependencies>
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>3.8.1</version>
          <scope>test</scope>
        </dependency>
        
      
        
        
        
        <dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
      </dependencies>
    </project>

2.编写两个servlet  
FirstServlet.Class 注解方式注册servlet

package per.czt.servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    @WebServlet(name="FirstServlet",urlPatterns="/first")
    public class FirstServlet extends HttpServlet {
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    
    		this.doGet(req, resp);
    
    	}
    
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		System.out.println("Hello,servlet!");
    		PrintWriter pw = resp.getWriter();
    		pw.println("Hello,servlet!");
    	}
    }

SecondServlet.Class 注解方式注册servlet

package per.czt.servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    @WebServlet(name="SecondServlet",urlPatterns="/second")
    public class SecondServlet extends HttpServlet {
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    
    		this.doGet(req, resp);
    
    	}
    
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		System.out.println("Hello,servlet2!");
    		PrintWriter pw = resp.getWriter();
    		pw.println("Hello,servlet2!");
    	}
    
    }

ThirdServlet.Class 通过编写方法的方式注册Servlet

package per.czt.servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class ThirdServlet extends HttpServlet {
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    
    		this.doGet(req, resp);
    
    	}
    
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		System.out.println("Hello,servlet3!");
    		PrintWriter pw = resp.getWriter();
    		pw.println("Hello,servlet3!");
    	}
    
    
    }

3.编写filter  
一:通过注解方式注册  
FirstFilter.Class 过滤url为/first的url

package per.czt.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;
    
    /**
     * 
     * 
     * 
     * 
     * <filter> 
     *   <filter-name>FirstFilter</filter-name>
     *   <filter-class>per.czt.filter.FirstFilter</filter-class>
     * </filter> 
     * <filter-mapping> 
     *   <filter-name>FirstFilter</filter-name>
     *   <url-pattern>/</url-pattern>
     * </filter-mapping>
     * 
     *
     */
    @WebFilter(filterName="FirstFilter",urlPatterns="/first")
    public class FirstFilter implements Filter {
    
    	public void init(FilterConfig filterConfig) throws ServletException {
    	
    
    	}
    
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    			throws IOException, ServletException {
    		System.out.println("进入FirstFilter");
    		chain.doFilter(request, response);
    		System.out.println("离开FirstFilter");
    
    	}
    
    	public void destroy() {
    		// TODO Auto-generated method stub
    
    	}
    	
    
    }

方式二:通过编写方法的方式整合filter  
ThirdFilter.Class

package per.czt.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 ThirdFilter implements Filter {
    
    	public void init(FilterConfig filterConfig) throws ServletException {
    		// TODO Auto-generated method stub
    
    	}
    
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    			throws IOException, ServletException {
    		System.out.println("进入ThirdFilter");
    		chain.doFilter(request, response);
    		System.out.println("离开ThirdFilter");
    		// TODO Auto-generated method stub
    
    	}
    
    	public void destroy() {
    		// TODO Auto-generated method stub
    
    	}
    
    }

4.启动类  
（1）采用App.Class的启动类

package per.czt;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.web.servlet.ServletComponentScan;
    import org.springframework.context.annotation.ComponentScan;
    
    /**
     * Hello world!
     *
     */
    @SpringBootApplication
    @ServletComponentScan
    public class App 
    {
        public static void main( String[] args )
        {
            SpringApplication.run(App.class, args);
        }
    }

测试发现FirstServlet通过了过滤器FirstFilter，SecondServlet没有通过过滤器，ThirdServlet没有被注册  
(2)通过编写ServletRegistrationBean和FilterRegistrationBean的方法分别注册ThirdServlet和ThirdFilter  
采用App3.Class的启动类

package per.czt;
    
    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 per.czt.filter.ThirdFilter;
    import per.czt.servlet.ThirdServlet;
    
    @SpringBootApplication
    
    public class App3 {
    
    	public static void main(String[] args) {
    		SpringApplication.run(App3.class, args);
    
    	}
    	@Bean
    	public ServletRegistrationBean getServletRegistrationBean() {
    		ServletRegistrationBean bean =new ServletRegistrationBean(new ThirdServlet());
    		
    		bean.addUrlMappings("/third");
    		return bean;
    	}
        @Bean
    	public FilterRegistrationBean getFilterRegistrationBean() {
    		FilterRegistrationBean bean=new FilterRegistrationBean(new ThirdFilter());
    		bean.addUrlPatterns("/third");
    		return bean;
    	}
    
    }

测试发现ThirdServlet注册并通过了ThirdFilter，其余servlet和filter均未被注册