如何在扩展 SpringBootServletInitializer 时注册 DispatcherServlets 并覆盖 onStartup

Question

我有一个 spring 启动应用程序正在部署到 Tomcat 的外部实例。主要的 class 扩展了 SpringBootServletInitializer 并覆盖了方法 configure 和 onStartup。在方法configure中，初始化了一个自定义环境，为activemq提供解密用户密码的加密器，因为jasypt是在activemq之后才初始化的。这是我从 jasypt-spring-boot 文档中得到的。

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
    try {
        StandardEncryptableServletEnvironment env = StandardEncryptableServletEnvironment.builder().encryptor(encryptor).build();
        return application.environment(env).sources(AxleServer.class);
    } catch (FileNotFoundException e) {
        logger.error("Could not load encryptable environment", e);
        return application.sources(AxleServer.class);
    }
}

在方法onStartup中我正在配置DispatcherServlets:

@Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.register(RemotingConfig.class);
        servletContext.addListener(new ContextLoaderListener(context));
        
        ServletRegistration.Dynamic restDispatcher = servletContext.addServlet("rest-dispatcher", new DispatcherServlet(context));
        restDispatcher.setLoadOnStartup(1);
        restDispatcher.addMapping("/rest/*");

        ServletRegistration.Dynamic remotingDispatcher = servletContext.addServlet("remoting-dispatcher", new DispatcherServlet(context));
        remotingDispatcher.setLoadOnStartup(2);
        remotingDispatcher.addMapping("/remoting/*");
    }

问题是 configure 方法从未被调用，因为它是从 onStartup 的超级实现中调用的。我尝试调用 super 实现 super.onStartup(servletContext); 但是我收到一个错误，指出在部署应用程序时根上下文已经存在。

注册 DispatcherServlets 和覆盖 onStartup 方法的正确方法是什么？是否需要调用onStartup的super实现？

Answer 1

我能够通过首先调用 super.onStartup 然后从 ServletContext 属性获取根上下文来解决这个问题

@Override
public void onStartup(ServletContext servletContext) throws ServletException {
    super.onStartup(servletContext);
    Object obj = servletContext.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
    if(obj instanceof AnnotationConfigServletWebServerApplicationContext) {
        AnnotationConfigServletWebServerApplicationContext context = (AnnotationConfigServletWebServerApplicationContext) obj;
        context.register(RemotingConfig.class);
            
        ServletRegistration.Dynamic restDispatcher = servletContext.addServlet("rest-dispatcher", new DispatcherServlet(context));
        restDispatcher.setLoadOnStartup(1);
        restDispatcher.addMapping("/rest/*");

        ServletRegistration.Dynamic remotingDispatcher = servletContext.addServlet("remoting-dispatcher", new DispatcherServlet(context));
        remotingDispatcher.setLoadOnStartup(2);
        remotingDispatcher.addMapping("/remoting/*");
    }
}

如何在扩展 SpringBootServletInitializer 时注册 DispatcherServlets 并覆盖 onStartup

How to register DispatcherServlets and override onStartup when extending SpringBootServletInitializer

spring

spring-boot

servlets

jasypt

servlet-listeners