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SpringBoot启动完成前后执行某个方法
- Authors
- Name
- ReLive27
在项目启动完成之前
实现ApplicationListener<ContextRefreshedEvent>
,ContextRefreshedEvent为启动事件。
@Component
public class ApplicationListenerDemo implements ApplicationListener<ContextRefreshedEvent> {
@Override
public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {
System.out.println("applicationListener before server success");
}
}
在项目启动完成之后
方式一 :实现ApplicationRunner接口
@Component
public class ApplicationRunnerDemo implements ApplicationRunner {
@Override
public void run(ApplicationArguments args) throws Exception {
System.out.println("run after server success");
}
}
方式二:实现CommandLineRunner接口
public class CommandLineRunnerDemo implements CommandLineRunner {
@Override
public void run(String... args) throws Exception {
System.out.println("commandLineRunner after server success");
}
}
原理
启动类的run方法调用了callRunners方法
public ConfigurableApplicationContext run(String... args) {
StopWatch stopWatch = new StopWatch();
stopWatch.start();
ConfigurableApplicationContext context = null;
Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList();
this.configureHeadlessProperty();
SpringApplicationRunListeners listeners = this.getRunListeners(args);
listeners.starting();
Collection exceptionReporters;
try {
ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
ConfigurableEnvironment environment = this.prepareEnvironment(listeners, applicationArguments);
this.configureIgnoreBeanInfo(environment);
Banner printedBanner = this.printBanner(environment);
context = this.createApplicationContext();
exceptionReporters = this.getSpringFactoriesInstances(SpringBootExceptionReporter.class, new Class[]{ConfigurableApplicationContext.class}, context);
this.prepareContext(context, environment, listeners, applicationArguments, printedBanner);
this.refreshContext(context);
this.afterRefresh(context, applicationArguments);
stopWatch.stop();
if (this.logStartupInfo) {
(new StartupInfoLogger(this.mainApplicationClass)).logStarted(this.getApplicationLog(), stopWatch);
}
listeners.started(context);
//执行callRunners方法
this.callRunners(context, applicationArguments);
} catch (Throwable var10) {
this.handleRunFailure(context, var10, exceptionReporters, listeners);
throw new IllegalStateException(var10);
}
try {
listeners.running(context);
return context;
} catch (Throwable var9) {
this.handleRunFailure(context, var9, exceptionReporters, (SpringApplicationRunListeners)null);
throw new IllegalStateException(var9);
}
}
callRunners方法会调用容器里所有实现了ApplicationRunner、CommandLineRunner接口的方法
private void callRunners(ApplicationContext context, ApplicationArguments args) {
List<Object> runners = new ArrayList();
runners.addAll(context.getBeansOfType(ApplicationRunner.class).values());
runners.addAll(context.getBeansOfType(CommandLineRunner.class).values());
AnnotationAwareOrderComparator.sort(runners);
Iterator var4 = (new LinkedHashSet(runners)).iterator();
while(var4.hasNext()) {
Object runner = var4.next();
if (runner instanceof ApplicationRunner) {
this.callRunner((ApplicationRunner)runner, args);
}
if (runner instanceof CommandLineRunner) {
this.callRunner((CommandLineRunner)runner, args);
}
}
}