SpringMVC-part2

SpringMVC-part2

首先對昨天的問題加以補充，今天空餘時間查詢了springmvc的參考文檔及api，發現以下幾個重要的地方

1

Below is an example of the Java configuration that registers and initializes the
DispatcherServlet.This class is auto-detected by the Servlet container (see Servlet Config):

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public class MyWebApplicationInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletCxt) {

        // Load Spring web application configuration
        AnnotationConfigWebApplicationContext ac = new AnnotationConfigWebApplicationContext();
        ac.register(AppConfig.class);
        ac.refresh();

        // Create and register the DispatcherServlet
        DispatcherServlet servlet = new DispatcherServlet(ac);
        ServletRegistration.Dynamic registration = servletCxt.addServlet("app", servlet);
        registration.setLoadOnStartup(1);
        registration.addMapping("/app/*");
    }
}

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2

In addition to using the ServletContext API directly, you can also extend AbstractAnnotationConfigDispatcherServletInitializer and override specific methods (see example under Context Hierarchy).

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Below is example configuration with a WebApplicationContext hierarchy:

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public class MyWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?[] { RootConfig.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?[] { App1Config.class };
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] { "/app1/*" };
    }
}

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可以看到，第二部分即爲我們昨天配置的dispatcherservlet初始化方法。在參考文檔中很明確的說明了，spring的初始化入口爲WebApplicationInitializer，但其內部實現了一個簡單的AbstractAnnotationConfigDispatcherServeltInitializer。我們只需要重寫三個接口就行。

3

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AbstractAnnotationConfigDispatcherServletInitializer

看一下spring官方api

其實springmvc只需要重寫兩個類。

• getRootConfigClasses() –
• getServletConfigClasses() –
  其實getRootConfigClasses和getServletConfigClass並沒有什麼不一樣，只是習慣性的在兩個配置文件中放入不同的配置信息，至於到底有哪些不一樣的地方，我還不明白。

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4

寫的太亂了點，當作自己筆記吧，下一章明確一下註解的作用。
@configuration
@component
@componentScan
@Bean