servlet

在app里面加入@ServletComponentScan

一种为

@WebServlet(value = {"/hello"})
@Slf4j
public class HelloServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                 response.setContentType("text/html;charser=uts-8");
        PrintWriter writer = response.getWriter();
        writer.print("nihao");
        log.info("hhhhhh");
    }
}

使用ServletRegistrationBean可以不用写

@WebServlet(value = {"/hello"})@ServletComponentScan

@Configuration
public class Myconfig {
    @Bean
    public ServletRegistrationBean servletRegistrationBean(){
        ServletRegistrationBean servletRegistrationBean=new ServletRegistrationBean();
        servletRegistrationBean.setServlet(new HelloServlet());
        servletRegistrationBean.addUrlMappings("/hello");
        return servletRegistrationBean;
    }

监听器

在app里面加入@ServletComponentScan

@WebListener
@Slf4j
public class ServletListener implements ServletRequestListener {
    @Override
    public void requestDestroyed(ServletRequestEvent sre) {
        log.info("有人");
    }

    @Override
    public void requestInitialized(ServletRequestEvent sre) {
        log.info("没人");
    }
}

使用ServletListenerRegistrationBean可以不用写@WebListener@ServletComponentScan

  @Bean
    public ServletListenerRegistrationBean servletListenerRegistrationBean(){
        ServletListenerRegistrationBean servletListenerRegistrationBean=new ServletListenerRegistrationBean();
        servletListenerRegistrationBean.setListener(new ServletListener());
        servletListenerRegistrationBean.setEnabled(true);
        return servletListenerRegistrationBean;
    }

Filter

依赖

 <dependency>
            <groupId>com.aliyun</groupId>
            <artifactId>alibaba-dingtalk-service-sdk</artifactId>
            <version>2.0.0</version>
        </dependency>

@Slf4j
@WebFilter("/api/*")
public class TokenFilter1 implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request=  (HttpServletRequest)servletRequest;
        HttpServletResponse response=  (HttpServletResponse)servletResponse;
        String token = request.getParameter("token");
        log.info("-------TokenFilter1开始------");
        //log.info("获取到token->{}",token);
        if(StrUtil.isEmpty(token)){
            response.sendRedirect("/logout");
            return;
        }
        StopWatch sw = new StopWatch();
        sw.start();
        filterChain.doFilter(servletRequest,servletResponse);
        sw.stop();
        log.info("-------TokenFilter1结束,耗时：{}------",sw.getTotalTimeSeconds());
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}

    @Bean
    public FilterRegistrationBean filterRegistrationBean(){
        FilterRegistrationBean filter = new FilterRegistrationBean();
        filter.setFilter(new TokenFilter1());
        filter.addUrlPatterns("/api/*");
        filter.setName("filter1");
        filter.setOrder(2);
        return filter;
    }
    @Bean
    public FilterRegistrationBean logfilterRegistrationBean(){
        FilterRegistrationBean filter = new FilterRegistrationBean();
        filter.setFilter(new LogFilter2());
        filter.addUrlPatterns("/api/*");
        filter.setName("filter2");
        filter.setOrder(1);
        return filter;
    }

logout为

package com.beiyou.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class LogOut {

    @GetMapping("/logout")
    public String logout(){

        return "滚出去";
    }
}

一、定义Servlet

package com.example.config;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getOutputStream().println("hello world...");
    }
}

二、注册Servlet

package com.example.config;

import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyServletRegistrationBean {

    @Bean
    public ServletRegistrationBean<MyServlet> initServletRegistrationBean(){
        ServletRegistrationBean<MyServlet> servletServletRegistrationBean=new ServletRegistrationBean<>();
        servletServletRegistrationBean.setServlet(new MyServlet());
        servletServletRegistrationBean.addUrlMappings("/welcome");
        return servletServletRegistrationBean;
    }

}

其中servletServletRegistrationBean.addUrlMappings(“/welcome”);这句来完成地址映射。
三、postman测试：

springboot servlet注册（ServletRegistrationBean）

作用：servlet可拦截指定url路径，添加自定义操作

*********************

相关类

HttpServlet

public abstract class HttpServlet extends GenericServlet {

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doHead(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doOptions(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void doTrace(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {

ServletRegistrationBean：servlet的注册类

public class ServletRegistrationBean<T extends Servlet> extends DynamicRegistrationBean<Dynamic> {
    private static final String[] DEFAULT_MAPPINGS = new String[]{"/*"};
    private T servlet;
    private Set<String> urlMappings;
    private boolean alwaysMapUrl;
    private int loadOnStartup;
    private MultipartConfigElement multipartConfig;

********************
构造函数

    public ServletRegistrationBean() {
    public ServletRegistrationBean(T servlet, String... urlMappings) {
    public ServletRegistrationBean(T servlet, boolean alwaysMapUrl, String... urlMappings) {


*********************
常用方法

    public void setServlet(T servlet) {    //设置servlet
    public T getServlet() {                //获取servlet

    public void setUrlMappings(Collection<String> urlMappings) {
    public Collection<String> getUrlMappings() {
    public void addUrlMappings(String... urlMappings) {  //添加映射路径

    public String getServletName() {   //获取servlet的名称

说明： urlappings不支持通配符，需为具体的路径

*********************

示例

*****************

servlet 层

MyServlet

public class MyServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getOutputStream().println("hello world");
    }
}

*****************

config 层

WebConfig：注册servlet

@Configuration
public class WebConfig {

    @Bean
    public ServletRegistrationBean<MyServlet>  initServletRegistrationBean(){
        ServletRegistrationBean<MyServlet> servletServletRegistrationBean=new ServletRegistrationBean<>();
        servletServletRegistrationBean.setServlet(new MyServlet());
        servletServletRegistrationBean.addUrlMappings("/hello");

        return servletServletRegistrationBean;
    }

}

*********************

测试输出

localhost:8080/hello