Spring Boot 整合Servlet

冷知识，几乎用不到

在spring boot中使用Servlet有两种实现方法；

方法一：

正常创建servlet,然后只用注解@ServletComponentScan

package clc.user.servlet;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

/**

 * ClassName: FirstServlet<br/>

 * Description:spring boot 整合sevlet <br/>

 * date: 2019/4/1 4:07 PM<br/>

 * <p>

 * 正常创建Servlet

 * 可以使用@WebServlet注解实现

 * 在spring boot启动类加注解@ServletComponentScan,会让spring启动时扫描@WebServlet注解并实例化

 *

 * @author chengluchao

 * @since JDK 1.8

 */

@WebServlet(name = "FirstServlet", urlPatterns = "/FirstServlet")

public class FirstServlet extends HttpServlet {

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        super.doGet(req, resp);

        System.out.println("FirstServlet");

    }

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        super.doPost(req, resp);

    }

}

对应的启动类：

@SpringBootApplication

@ServletComponentScan

public class UserServiceApplication {

    public static void main(String[] args) {

        SpringApplication.run(UserServiceApplication.class, args);

    }

}

----------

方法二：

正常创建Servlet，但不对其进行配置，放到启动类来操作

package clc.user.servlet;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

/**

 * ClassName: SecondServlet<br/>

 * Description:spring boot 整合sevlet <br/>

 * date: 2019/4/1 4:07 PM<br/>

 * <p>

 *

 * @author chengluchao

 *

 * 需要：

 * @Bean public ServletRegistrationBean getServletRegistrationBean() {

 * ServletRegistrationBean bean = new ServletRegistrationBean(new SecondServlet());

 * bean.addUrlMappings("SecondServlet");

 * return bean;

 * }

 * @since JDK 1.8

 */

public class SecondServlet extends HttpServlet {

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        super.doGet(req, resp);

        System.out.println("SecondServlet");

    }

    @Override

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        super.doPost(req, resp);

    }

}

@SpringBootApplication

public class UserServiceApplication2 {

    @Bean

    public ServletRegistrationBean getServletRegistrationBean() {

        ServletRegistrationBean bean = new ServletRegistrationBean(new SecondServlet());

        bean.addUrlMappings("/SecondServlet");

        return bean;

    }

    public static void main(String[] args) {

        SpringApplication.run(UserServiceApplication2.class, args);

    }

}