EnvironmentPostProcessorApplicationListener是专门用来处理EnvironmentPostProcessor实现类的。

    1. public class EnvironmentPostProcessorApplicationListener implements SmartApplicationListener, Ordered {
    3.     public static final int DEFAULT_ORDER = Ordered.HIGHEST_PRECEDENCE + 10;
    5.     private final DeferredLogs deferredLogs;
    6.     private int order = DEFAULT_ORDER;
    8.     private final Function<ClassLoader, EnvironmentPostProcessorsFactory> postProcessorsFactory;
    10.     EnvironmentPostProcessorApplicationListener(
    11.         Function<ClassLoader, EnvironmentPostProcessorsFactory> postProcessorsFactory, DeferredLogs deferredLogs) {
    12.         this.postProcessorsFactory = postProcessorsFactory;
    13.         this.deferredLogs = deferredLogs;
    14.     }
    16.     // 支持的事件类型
    17.     @Override
    18.     public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
    19.         return ApplicationEnvironmentPreparedEvent.class.isAssignableFrom(eventType)
    20.             || ApplicationPreparedEvent.class.isAssignableFrom(eventType)
    21.                 || ApplicationFailedEvent.class.isAssignableFrom(eventType);
    22.     }
    24.     // 事件处理
    25.     @Override
    26.     public void onApplicationEvent(ApplicationEvent event) {
    27.         // 环境准备完成事件
    28.         if (event instanceof ApplicationEnvironmentPreparedEvent) {
    29.             onApplicationEnvironmentPreparedEvent((ApplicationEnvironmentPreparedEvent) event);
    30.         }
    31.         // 应用准备完成事件
    32.         if (event instanceof ApplicationPreparedEvent) {
    33.             onApplicationPreparedEvent();
    34.         }
    35.         // 应用失败事件
    36.         if (event instanceof ApplicationFailedEvent) {
    37.             onApplicationFailedEvent();
    38.         }
    39.     }
    41.     // 处理Enviroment环境上下文准备完成事件
    42.     private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {
    43.         ConfigurableEnvironment environment = event.getEnvironment();
    44.         SpringApplication application = event.getSpringApplication();
    45.         for (EnvironmentPostProcessor postProcessor : getEnvironmentPostProcessors(application.getResourceLoader(),
    46.                                                                                    event.getBootstrapContext())) {
    47.             // processor#process
    48.             postProcessor.postProcessEnvironment(environment, application);
    49.         }
    50.     }
    52.     private void onApplicationPreparedEvent() {
    53.         finish();
    54.     }
    56.     private void onApplicationFailedEvent() {
    57.         finish();
    58.     }
    60.     private void finish() {
    61.         this.deferredLogs.switchOverAll();
    62.     }
    64.     // SPI加载所有的EnvironmentPostProcessor
    65.     List<EnvironmentPostProcessor> getEnvironmentPostProcessors(ResourceLoader resourceLoader,
    66.                                                                 ConfigurableBootstrapContext bootstrapContext) {
    67.         ClassLoader classLoader = (resourceLoader != null) ? resourceLoader.getClassLoader() : null;
    68.         EnvironmentPostProcessorsFactory postProcessorsFactory = this.postProcessorsFactory.apply(classLoader);
    69.         return postProcessorsFactory.getEnvironmentPostProcessors(this.deferredLogs, bootstrapContext);
    70.     }
    71. }

    EnvironmentPostProcessor的实现类
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