Springboot项目全部依赖注解的,web工程是如何启动的
1 首先引入了Tomcat依赖,然后用java代码启动Tomcat容器,默认Tomcat版本是8.5版本
2 Tomcat是实现了servlet3.0规范,在servlet加载类的过程中会寻找实现了ServletContainerInitializer接口的类,spring为我们实现了这个接口的类是SpringServletContainerInitializer,最后又会去调用实现了WebApplicationInitializer接口的类,最后真正是实现WebApplicationInitializer接口的是这个AbstractAnnotationConfigDispatcherServletInitializer,然后在该类中去初始化spring容器和springmvc容器和servlet拦截的url
public class AppTomcat { public static void main(String[] args) throws ServletException, LifecycleException {
start();
} public static void start() throws ServletException, LifecycleException {
//创建Tomcat容器和设置端口
Tomcat tomcatServer = new Tomcat();
tomcatServer.setPort(); StandardContext ctx = (StandardContext) tomcatServer.addWebapp("/", new File("src/main").getAbsolutePath());
ctx.setReloadable(false);
WebResourceRoot resources = new StandardRoot(ctx); File additionWebInfClasses = new File("target/classes");
//告诉Tomcat项目的class目录,根目录
resources.addPreResources(
new DirResourceSet(resources, "/WEB-INF/classes", additionWebInfClasses.getAbsolutePath(), "/"));
//启动容器
tomcatServer.start();
tomcatServer.getServer().await(); }}
项目结构:
github下载地址:https://github.com/jake1263/MySpringBoot