自己实现 SpringMVC 底层机制 系列之搭建 SpringMVC 底层机制开发环境和开发 WyxDispatcherServlet

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

        <!--引入原生servlet依赖 的jar-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <!--解读
            1. scope标签表示引入的jar的作用范围
            2. provided:表示该项目在打包,放到生产环境的时候，不需要带上servlet-api.jar
            3. 因为tomcat本身是有servlet的jar, 到时直接使用tomcat本身的servlet-api.jar,防止版本冲突
            4. 后面在讲解maven时，还有详细讲解
            -->
            <scope>provided</scope>
        </dependency>

        <!--引入dom4j,解析xml文件-->
        <dependency>
            <groupId>dom4j</groupId>
            <artifactId>dom4j</artifactId>
            <version>1.6.1</version>
        </dependency>

        <!--引入常用工具类的jar 该jar含有很多常用的类-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.5</version>
        </dependency>

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

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>
  
  <!--配置WyxDispatcherServlet, 作为我们自己的前端控制器-->
  <servlet>
    <servlet-name>WyxDispatcherServlet</servlet-name>
    <servlet-class>com.wyxdu.wyxspringmvc.servlet.WyxDispatcherServlet</servlet-class>
    <!--给WyxDispatcherServlet配置参数，指定要操作的spring容器配置文件-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:wyxspringmvc.xml</param-value>
    </init-param>
    <!--WyxDispatcherServlet在tomcat启动时，就自动加载-->
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>WyxDispatcherServlet</servlet-name>
    <!--因为WyxDispatcherServlet作为前端控制器,所以需要拦截所有请求,url-pattern配置 /-->
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

public class WyxDispatcherServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws
            ServletException, IOException {
        System.out.println("WyxDispatcherServlet doGet()被调用");
    }
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws
            ServletException, IOException {
        System.out.println("WyxDispatcherServlet doPost()被调用");
    }
}