第五篇：Spring Boot整合filter

一、Springboot整合Servlet

第一种方案：通过注解扫描完成filter组建的注册

• 1、编写自定义filter(FirstFilter)

//urlPattern是一个数组可以添加多个
//@WebFilter(filterName = "FirstFilter",urlPatterns = {"*.do","*.jsp"})
@WebFilter(filterName = "FirstFilter", urlPatterns = {"/first"})
public class FirstFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @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() {
    }
}

• 2、创建servlet(测试用)

@WebServlet(name = "FirstServlet",urlPatterns = "/first")
public class FirstServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("FirstServlet启动........");
    }
}

• 3、编写一个启动类,并在启动类上添加注解

@SpringBootApplication
@ServletComponentScan
//在springboot启动时会扫描@Webfilter注解和@webFilter注解，并将该类实例化
public class SpringBootChapter1Application {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootChapter1Application.class, args);
    }

}

• 4、启动项目及浏览器验证：​​http://localhost:8080/first​​
• 5、查看控制台

第二种方案：通过方法完成filter组件注册

• 1、编写一个自定义的filter

public class SecondFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("进入SecondFilter");
        //放行
        chain.doFilter(request, response);
        System.out.println("离开SecondFilter");
    }

    @Override
    public void destroy() {
    }
}

• 2、创建一个servlet(测试用)

public class SecondServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("SecondServlet启动........");
    }
}

• 3、创建一个启动类

/**
 * @author gblfy
 * @ClassNme AppFilter2
 * @Description springboot整合filter方式2
 * @Date 2019/2/20 13:45
 * @version1.0
 */
@SpringBootApplication
public class SpringbootFilterApplication2 {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootFilterApplication2.class, args);
    }

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

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

• 4、启动项目及浏览器验证：​​http://localhost:8080/second​​
• 5、查看控制台

本文源码下载：

github地址：
​​​https://github.com/gb-heima/Spring-Boot-Actual-Combat/tree/master/parent/spring-boot-chapter-5​​