Spring WebAppInitializer

Posted 2022-10-08 develon

Spring WebAppInitializer 的原理与用例

使用 Spring 框架的时候, 通常是需要在 web.xml 中配置的, 比如配置 DispatcherServlet, 是通过对 URL 做映射实现的

    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.</url-pattern>
    </servlet-mapping>

然后在 $ servlet-name -servlet.xml 中定义扫描 Controller 组件的包

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="package.controller, another.package"/>

    <!-- ... -->

</beans>

这不免有些繁琐, 有没有更简单的方式呢? 有!, spring-webmvc 中提供了抽象类 AbstractAnnotationConfigDispatcherServletInitializer, 继承并实现它, 容器会自动实例化它!