Spring Boot2.0之原理—创建内置Tomcat容器-优快云博客

Spring Boot2.0之原理—创建内置Tomcat容器

前面所述的https://www.cnblogs.com/toov5/p/9823728.html 中的第一条先不赘述了，就是玩了maven

重点介绍后两条

首先内置Tomcat：

SpringBoot中内置tomcat服务器

Java操作创建tomcat

我们点击pom中的

持续点击到

继续点击会发现：

这个依赖为我所需~

注意：Springboot2.0之后 Tomcat8.0以上版本

引入到自己的pom中（类似的还有其他的依赖包）：

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.toov5.tomcat</groupId>
  <artifactId>tomcat</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <dependencies>
        <!--Java语言操作tomcat -->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-core</artifactId>
            <version>8.5.16</version>
        </dependency>
        
        <!-- tomcat对jsp支持 -->
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jasper</artifactId>
            <version>8.5.16</version>
        </dependency>
    </dependencies>    

  
</project>

servlet代码：

package com.toov5.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class IndexServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().print("successful congratulation ");
    }
}

然后用servlet创建Tomcat容器

package com.toov5.tomcat;

import org.apache.catalina.LifecycleException;
import org.apache.catalina.core.StandardContext;
import org.apache.catalina.startup.Tomcat;
import org.apache.catalina.startup.Tomcat.FixContextListener;

import com.toov5.servlet.IndexServlet;

//使用Java创建Tomcat容器
//tomcat 底层执行程序  最终执行servlet
//Springmvc底层使用servlet

public class Test {
       private static int PORT = 8080; //端口
       private static String CONTEX_PATH = "/toov5";  //项目访问名称
       private static String SERVLET_NAME="IndexServet";
       public static void main(String[] args) {
        Tomcat tomcatServer =  new Tomcat();
        tomcatServer.setPort(PORT);  //指定端口号
        //是否设置自动部署
        tomcatServer.getHost().setAutoDeploy(false);
        //创建上下文,拿到上下文后就可以设置整个访问地址了
        StandardContext standardContext = new StandardContext();
        standardContext.setPath(CONTEX_PATH); 
        //监听上下文
        standardContext.addLifecycleListener(new FixContextListener());
        standardContext.addLifecycleListener(new FixContextListener());
        // tomcat容器添加standardContext 添加整个context
        tomcatServer.getHost().addChild(standardContext);
        // 创建servlet   servlet的名字叫IndexServlet   
        tomcatServer.addServlet(CONTEX_PATH, SERVLET_NAME, new IndexServlet());
        // 添加servleturl映射
        standardContext.addServletMappingDecoded("/index", SERVLET_NAME);
        try {
            tomcatServer.start();
        } catch (LifecycleException e) {
            e.printStackTrace();
        }
        System.out.println("tomcat服务器启动成功！");
        //需要异步接受请求
            tomcatServer.getServer().await();    
    }  
     
       
      

}

这段代码等同于，

web.xml中的：

<servlet>
  <servlet-name>toov5</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring/springmvc.xml</param-value>
   </init-param>
</servlet>
<servlet-mapping>
 <servlet-name>toov5</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

项目目录结构：