spring boot 源码之SpringApplicationRunListeners

SpringApplicationRunListeners

　　SpringApplicationRunListener的集合，内部存储了SpringApplicationRunListener的集合，提供了SpringApplicationRunListener一样方法，方便统一遍历调用所有SpringApplicationRunListener。

private final List<SpringApplicationRunListener> listeners;
    SpringApplicationRunListeners(Log log,
            Collection<? extends SpringApplicationRunListener> listeners) {
        this.log = log;
        this.listeners = new ArrayList<>(listeners);
    }
    public void starting() {
        for (SpringApplicationRunListener listener : this.listeners) {
            listener.starting();
        }
    }
    public void environmentPrepared(ConfigurableEnvironment environment) {
        for (SpringApplicationRunListener listener : this.listeners) {
            listener.environmentPrepared(environment);
        }
    }
    public void contextPrepared(ConfigurableApplicationContext context) {
        for (SpringApplicationRunListener listener : this.listeners) {
            listener.contextPrepared(context);
        }
    }
    public void contextLoaded(ConfigurableApplicationContext context) {
        for (SpringApplicationRunListener listener : this.listeners) {
            listener.contextLoaded(context);
        }
    }
    public void finished(ConfigurableApplicationContext context, Throwable exception) {
        for (SpringApplicationRunListener listener : this.listeners) {
            callFinishedListener(listener, context, exception);
        }
    }

SpringApplicationRunListener

　　springApplication运行的监听器，在相应的节点执行回调方法。

public interface SpringApplicationRunListener {

    /**
     * springApplication的run方法一执行就调用。
     */
    void starting();

    /**
     * Called once the environment has been prepared, but before the
     * {@link ApplicationContext} has been created.
     * @param environment the environment
     */
    void environmentPrepared(ConfigurableEnvironment environment);

    /**
     * Called once the {@link ApplicationContext} has been created and prepared, but
     * before sources have been loaded.
     * @param context the application context
     */
    void contextPrepared(ConfigurableApplicationContext context);

    /**
     * Called once the application context has been loaded but before it has been
     * refreshed.
     * @param context the application context
     */
    void contextLoaded(ConfigurableApplicationContext context);

    /**
     * 在springApplication的run方法完成前被调用*/
    void finished(ConfigurableApplicationContext context, Throwable exception);

}