Spring Boot Application Internally Works
Steps
- 初期化
フェーズ
new SpringApplication()コンストラクタを呼 び出 し、Spring アプリケーションインスタンスを作成 。 コンストラクタ内 で起動 環境 の初期化 作業 を完了 し、初期 パラメータを設定 。- Spring Application タイプの判定
==>
Web Servlet / Reactive Servlet
- Spring Application タイプの判定
==>
SpringApplication.run()run() を呼 び出 し、すべての起動 作業 がこのメソッド内 で完了 。- 準備 フェーズ (Environment Setup)
- イベント発行
- Context と Bean の作成
- Context の更新
- 最終 フェーズ処理
初期化
public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
this.sources = new LinkedHashSet();
this.bannerMode = Mode.CONSOLE;
this.logStartupInfo = true;
this.addCommandLineProperties = true;
this.addConversionService = true;
this.headless = true;
this.registerShutdownHook = true;
this.additionalProfiles = Collections.emptySet();
this.isCustomEnvironment = false;
this.lazyInitialization = false;
this.applicationContextFactory = ApplicationContextFactory.DEFAULT;
this.applicationStartup = ApplicationStartup.DEFAULT;
this.resourceLoader = resourceLoader;
Assert.notNull(primarySources, "PrimarySources must not be null");
this.primarySources = new LinkedHashSet(Arrays.asList(primarySources));
this.webApplicationType = WebApplicationType.deduceFromClasspath();
this.bootstrapRegistryInitializers = new ArrayList(this.getSpringFactoriesInstances(BootstrapRegistryInitializer.class));
this.setInitializers(this.getSpringFactoriesInstances(ApplicationContextInitializer.class));
this.setListeners(this.getSpringFactoriesInstances(ApplicationListener.class));
this.mainApplicationClass = this.deduceMainApplicationClass();
}@SpringBootApplication アノテーション内容
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(
excludeFilters = {@Filter(
type = FilterType.CUSTOM,
classes = {TypeExcludeFilter.class}
), @Filter(
type = FilterType.CUSTOM,
classes = {AutoConfigurationExcludeFilter.class}
)}
)@SpringBootConfiguration==>@Configuration現在 のクラスを Spring IoC の設定 クラスとして登録 。
run()
SpringApplicationRunListeners
class SpringApplicationRunListeners {
private final Log log;
private final List<SpringApplicationRunListener> listeners;
private final ApplicationStartup applicationStartup;
SpringApplicationRunListeners(Log log, List<SpringApplicationRunListener> listeners,
ApplicationStartup applicationStartup) {
this.log = log;
this.listeners = List.copyOf(listeners);
this.applicationStartup = applicationStartup;
}
void starting(ConfigurableBootstrapContext bootstrapContext, Class<?> mainApplicationClass) {
doWithListeners("spring.boot.application.starting", (listener) -> listener.starting(bootstrapContext),
(step) -> {
if (mainApplicationClass != null) {
step.tag("mainApplicationClass", mainApplicationClass.getName());
}
});
}
void environmentPrepared(ConfigurableBootstrapContext bootstrapContext, ConfigurableEnvironment environment) {
doWithListeners("spring.boot.application.environment-prepared",
(listener) -> listener.environmentPrepared(bootstrapContext, environment));
}
void contextPrepared(ConfigurableApplicationContext context) {
doWithListeners("spring.boot.application.context-prepared", (listener) -> listener.contextPrepared(context));
}
void contextLoaded(ConfigurableApplicationContext context) {
doWithListeners("spring.boot.application.context-loaded", (listener) -> listener.contextLoaded(context));
}
void started(ConfigurableApplicationContext context, Duration timeTaken) {
doWithListeners("spring.boot.application.started", (listener) -> listener.started(context, timeTaken));
}
void ready(ConfigurableApplicationContext context, Duration timeTaken) {
doWithListeners("spring.boot.application.ready", (listener) -> listener.ready(context, timeTaken));
}
void failed(ConfigurableApplicationContext context, Throwable exception) {
doWithListeners("spring.boot.application.failed",
(listener) -> callFailedListener(listener, context, exception), (step) -> {
step.tag("exception", exception.getClass().toString());
step.tag("message", exception.getMessage());
});
}
private void callFailedListener(SpringApplicationRunListener listener, ConfigurableApplicationContext context,
Throwable exception) {
try {
listener.failed(context, exception);
}
catch (Throwable ex) {
if (exception == null) {
ReflectionUtils.rethrowRuntimeException(ex);
}
if (this.log.isDebugEnabled()) {
this.log.error("Error handling failed", ex);
}
else {
String message = ex.getMessage();
message = (message != null) ? message : "no error message";
this.log.warn("Error handling failed (" + message + ")");
}
}
}
private void doWithListeners(String stepName, Consumer<SpringApplicationRunListener> listenerAction) {
doWithListeners(stepName, listenerAction, null);
}
private void doWithListeners(String stepName, Consumer<SpringApplicationRunListener> listenerAction,
Consumer<StartupStep> stepAction) {
StartupStep step = this.applicationStartup.start(stepName);
this.listeners.forEach(listenerAction);
if (stepAction != null) {
stepAction.accept(step);
}
step.end();
}
}