第七章 Spring Boot 启动配置原理
启动原理，运行流程，自动配置原理
run()
- 准备环境
执行 ApplicationContextInitializer.initialize()
监听器 SpringApplicationRunListener 回调 contextPrepared
加载主配置类定义信息
监听器 SpringApplicationRunListener 回调 contextLoaded
刷新启动 ICO 容器
扫描加载所有容器中的组件
包括从 META-INF/spring.factories 中获取所有 EnableAutoConfiguration 组件
回调容器中所有的 ApplicationRunner/CommandLineRunner 的 run 方法
监听器 SpringApplicationRunListener 回调 finished
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监听器配置示例
配置目录：
src/main/java/com/example/demo/listener/ - MyApplicationContextInitializer.java - MySpringApplicationRunListener.java - MyApplicationRunner.java - MyCommandLineRunner.java
实现类
package com.example.demo.listener; import org.springframework.context.ApplicationContextInitializer; import org.springframework.context.ConfigurableApplicationContext; public class MyApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> { @Override public void initialize(ConfigurableApplicationContext applicationContext) { System.out.println("MyApplicationContextInitializer initialize" + applicationContext); } }
package com.example.demo.listener; import org.springframework.boot.SpringApplication; import org.springframework.boot.SpringApplicationRunListener; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.core.env.ConfigurableEnvironment; public class MySpringApplicationRunListener implements SpringApplicationRunListener { public MySpringApplicationRunListener(SpringApplication application, String[] args) { } @Override public void starting() { System.out.println("MySpringApplicationRunListener starting"); } @Override public void environmentPrepared(ConfigurableEnvironment environment) { Object name = environment.getSystemProperties().get("os.name"); System.out.println("environmentPrepared" + name); } @Override public void contextPrepared(ConfigurableApplicationContext context) { System.out.println("contextPrepared"); } @Override public void contextLoaded(ConfigurableApplicationContext context) { System.out.println("contextLoaded"); } @Override public void started(ConfigurableApplicationContext context) { System.out.println("started"); } @Override public void failed(ConfigurableApplicationContext context, Throwable exception) { System.out.println("failed"); } @Override public void running(ConfigurableApplicationContext context) { System.out.println("running"); } }
package com.example.demo.listener; import org.springframework.boot.ApplicationArguments; import org.springframework.boot.ApplicationRunner; import org.springframework.stereotype.Component; @Component public class MyApplicationRunner implements ApplicationRunner { @Override public void run(ApplicationArguments args) throws Exception { System.out.println("MyApplicationRunner"); } }
package com.example.demo.listener; import org.springframework.boot.ApplicationArguments; import org.springframework.boot.ApplicationRunner; import org.springframework.stereotype.Component; @Component public class MyApplicationRunner implements ApplicationRunner { @Override public void run(ApplicationArguments args) throws Exception { System.out.println("MyApplicationRunner"); } }
src/main/resources/META-INF/spring.factories
org.springframework.boot.SpringApplicationRunListener=\
com.example.demo.listener.MySpringApplicationRunListener
org.springframework.context.ApplicationContextInitializer=\
com.example.demo.listener.MyApplicationContextInitializer
