使用java config 配置spring 和spring mvc

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无xml配置的环境,主要基于java config

1. 继承AbstractAnnotationConfigDispatcherServletInitializer

public class ApplicationInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    /**
     * 启动器
     *
     * @param servletContext servletContext
     * @throws ServletException ServletException
     */
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        //调用父类的方法启动spring
        super.onStartup(servletContext);
        //自定义的serlvet注册
        customizeRegistrationServlet(servletContext);
    }

    /**
     * spring根容器注解扫描,扫描controller之外的包,一些基于java config 的配置类
     */
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[]{};
    }


    /**
     * 注册自定义的Servlet,listener 等
     *
     * @param servletContext servletContext
     */
    private void customizeRegistrationServlet(ServletContext servletContext) {

    }

    /**
     * 注册 Filter,父类中返回null 子类可以覆盖此方法 ,注册Filter
     *
     * @return Filter[]
     */
    @Override
    protected Filter[] getServletFilters() {
        return new Filter[]{};
    }

    /**
     * spring mvc 容器启动时的监听
     *
     * @return ApplicationContextInitializer<?>[]
     */
    @Override
    protected ApplicationContextInitializer<?>[] getServletApplicationContextInitializers() {
        SpringMvcAppInitListener applicationContextInitializer = new SpringMvcAppInitListener();
        return new ApplicationContextInitializer[]{applicationContextInitializer};
    }

    /**
     * spring 根容器启动时的监听事件,可以提前初始化一些配置,可以实现
     * 区分spring boot 加载不同的配置文件.区分dev . test . prod
     *
     * @return ApplicationContextInitializer<?>[]
     */
    @Override
    protected ApplicationContextInitializer<?>[] getRootApplicationContextInitializers() {
        SpringRootAppInitListener springRootAppInitListener = new SpringRootAppInitListener();
        return new ApplicationContextInitializer[]{springRootAppInitListener};
    }

    /**
     * spring mvc的注解扫描，只扫描controller的包
     */
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{SpringMvcConfig.class};
    }

    /**
    *DispatcherServlet 映射路径,DispatcherServlet 本身就是一个Serlvet
    */
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    /**
    *   DispatcherServlet 配置项
    */
    @Override
    protected void customizeRegistration(Dynamic registration) {
        registration.setInitParameter("dispatchOptionsRequest", "true");
        super.customizeRegistration(registration);
    }

}

自此整个配置就结束了,下面分析下自定义实现spring boot 基于不同的环境加载不同配置文件.