Spring Boot - Servlet Filter

filter对象能够拦截应用程序的HTTP request和response，我们可以在以下两个场景中使用到过滤器：

发送request请求给控制器前

发送response响应给客户端前
如下代码将会展示简单的过滤器实现Filter接口并标注@Component注解：


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

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

    @Override
    public void destroy() { }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("Remote Host: " + servletRequest.getRemoteAddr());
        System.out.println("Remote Address: " + servletRequest.getRemoteAddr());
        filterChain.doFilter(servletRequest,servletResponse);
    }
}

测试：