springBoot 整合servlet

一：用idea 创建 springboot 项目：

详情请参考：《使用IDEA创建一个springboot项目》

二：具体代码内容；

一： FirstServlet

package com.alancode.springboot.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;

/**
 * @program: springBootAddServlet
 * @description: FristServlet
 *  一：传统的spring 框架增加 servlet 的配置方式
 *   <servlet>
 *       <servlet-name>FirstServlet</servlet-name>
 *       <servlet-class>com.alancode.springboot.Servlet.FirstServlet</servlet-class>
 *   </servlet>
 *   <servlet-mapping>
 *       <servlet-name>FirstServlet</servlet-name>
 *       <url-pattern>/frist</url-pattern>
 *   </servlet-mapping>
 *
 */
/***springBoot  配置 servlet 的配置代码
 * @author Alan_Liu***/
@WebServlet(name="FirstServlet",urlPatterns = "/frist")
public class FirstServlet extends HttpServlet {
    /**
     *
     *
     *@Param: [req, resp]
     *@return
     *@throws
     *@author Alan_Liu
     *@date   2021/2/14 23:22
     *
     **/
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //super.doGet(req,resp);
		System.out.println("------------springBoot 整合 servlet 方式一：注解配置方式------------------------------------------ -----------");
		System.out.println("-----------项目启动时候加载 @WebServlet 注解下的FirstServlet 类 - ---------------------------------");
		System.out.println("-----------当进行http://localhost:8080/frist 的浏览器地址访问后，进输出该打印内容 - ----------------------");
	}
}

二：SecondServlet

package com.alancode.springboot.Servlet;
/**
 * @author Alan_liu
 * @Create 2021/2/14 23:46
 */

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

/**
 *@program: springBootAddServlet
 *@description: SecondServlet
 *@author: Alan_Liu
 *@create: 2021-02-14 23:46
 */
public class SecondServlet extends HttpServlet {


	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		//super.doGet(req,resp);
		System.out.println("------------springBoot 整合 servlet 方式二： ------------------------------------------ -----------");
		System.out.println("-----------项目启动SpringBootAddServletApplication2时候加载声明初始化SecondServlet 类  - ---------------------------------");
		System.out.println("-----------当进行http://localhost:8080/second 的浏览器地址访问后，进输出该打印内容 - ----------------------");

	}
}

三：SpringBootAddServletApplication

package com.alancode.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.boot.web.servlet.ServletComponentScan;

/**
 * @author Alan_Liu
 */
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
@ServletComponentScan
public class SpringBootAddServletApplication {

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

}

/***
 *
 *
 **注意：
 **关于编写启动器需要注意的问题。
 **启动器存放位置：启动器可以和controller 位于同一个包 package下，或者位于controller的上一级包。
 **但是不能把该文件放到controller平行级的包或者其子包下。
 * ServletComponentScan 含义：
 *   在springboot 启动时候进行扫描@webServlet注解的所有servlet类。并将该类实例化
 *
 * ***/

四：SpringBootAddServletApplication2

package com.alancode.springboot;

import com.alancode.springboot.Servlet.SecondServlet;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;

/**
 * @author Alan_Liu
 */
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})
public class SpringBootAddServletApplication2 {

	public static void main(String[] args) {
		SpringApplication.run(SpringBootAddServletApplication2.class, args);
	}
	@Bean
	public ServletRegistrationBean getServletRegistrationBean(){
		ServletRegistrationBean bean=new ServletRegistrationBean(new SecondServlet());
		bean.addUrlMappings("/second");
		System.out.println("------------springBoot 整合 servlet 方式二： ------------------------------------------ -----------");
		System.out.println("-----------项目启动SpringBootAddServletApplication2时候加载声明初始化SecondServlet 类  - ---------------------------------");
		System.out.println("-----------当进行http://localhost:8080/second 的浏览器地址访问后，进输出该打印内容 - ----------------------");

		return  bean;
	}
}

/***
 *
 *
 **注意：
 **关于编写启动器需要注意的问题。
 **启动器存放位置：启动器可以和controller 位于同一个包 package下，或者位于controller的上一级包。
 **但是不能把该文件放到controller平行级的包或者其子包下。
 * ServletComponentScan 含义：
 *   在springboot 启动时候进行扫描@webServlet注解的所有servlet类。并将该类实例化
 *
 * ***/

五：pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.AlanCode.springBoot</groupId>
    <artifactId>springBootAddServlet</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springBootAddServlet</name>
    <description>springBootAddServlet</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>