SpringBoot整合Filter

1.通过注解扫描完成Filter组件的注册

1.1 编写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里面编写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过滤器
 */
//@WebFilter(filterName = "FirstFilter",urlPatterns ={"*.do","*.jsp"})
@WebFilter(filterName = "FirstFilter",urlPatterns = "/first")
public class FirstFilter implements Filter {

    //doFilter一般是对request（请求）执行过滤操作
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("进入Filter");
//        放行
       chain.doFilter(request,response);
        System.out.println("离开Filter");
    }

    @Override
    public void destroy() {

    }

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

    }
}

1.2 编写启动类

/**
 * 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 启动main 在浏览器打开http://localhost:8080/forst

2.通过方法完成Filter组件的注册

2.1编写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 编写启动类

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

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

    /**
     * Filter注册方法
     * @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

小结：整合Filter有两种方式：1.注解：@WebFilter  2.方法：@SpringBootApplication  SpringBootAppion.run(,) @Bean  ServletRegistrationBean addUrlPattern  FileRegisterationBean addUrlPatter