SpringBoot整合Filter

1.通過注解掃描完成Filter組件的注冊

1.1 編寫Filter

package com.demo.filter;



import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

/**
 * springboot整合Filter方式一
 * 以往在web.xml里面編寫filter
 * <filter>
 *     <filter-name>FirstFilter</filter-name>
 *     <filter-class>com.demo.filter.FirstFilter</filter-class>
 * </filter>
 *
 * <filter-mapping>
 *     <filtr-name>FirstFilter</filtr-name>
 *     <url-pattern>/hello</url-pattern>
 * </filter-mapping>
 *
 * filter過濾器
 */
//@WebFilter(filterName = "FirstFilter",urlPatterns ={"*.do","*.jsp"})
@WebFilter(filterName = "FirstFilter",urlPatterns = "/first")
public class FirstFilter implements Filter {

    //doFilter一般是對request（請求）執行過濾操作
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("進入Filter");
//        放行
       chain.doFilter(request,response);
        System.out.println("離開Filter");
    }

    @Override
    public void destroy() {

    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }
}

1.2 編寫啟動類

/**
 * springBoot整合Filter 方式一
 */
@SpringBootApplication
@ServletComponentScan
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class,args);
    }
}

1.3 啟動main 在瀏覽器打開http://localhost:8080/forst

2.通過方法完成Filter組件的注冊

2.1編寫Filter

/**
 * springboot整合servlet方式二
 */
public class SecondServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("SecondServlet...........");

    }
}

2.2 編寫啟動類

/**
 * springBoot整合Filter 方式二
 */
@SpringBootApplication
public class App2 {
 public static void main(String[] args) {
 SpringApplication.run(App2.class,args);
 }

 /**
 * servlet的注冊
 * @return
 */
 @Bean
 public ServletRegistrationBean getServletRegistrationBean(){
 ServletRegistrationBean bean=new ServletRegistrationBean(new SecondServlet());
 bean.addUrlMappings("/second");
 return bean;
 }

 /**
 * Filter注冊方法
 * @return
 */
 @Bean
 public FilterRegistrationBean getFilterRegistrationBean(){
 FilterRegistrationBean bean=new FilterRegistrationBean(new SecondFilter());
 // bean.addUrlPatterns(new String[]{"*.do",".jsp"});
 bean.addUrlPatterns("/second");
 return bean;
 }
}

以下如上

小結：整合Filter有兩種方式：1.注解：@WebFilter  2.方法：@SpringBootApplication  SpringBootAppion.run(,) @Bean  ServletRegistrationBean addUrlPattern  FileRegisterationBean addUrlPatter