SpringBoot——自定义start

在Spring Boot中，可以通过实现ApplicationContextInitializer接口来自定义Spring应用上下文的初始化。

以下是一个简单的示例，演示如何创建一个自定义的ApplicationContextInitializer：

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;
 
public class CustomStartApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
 
    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        ConfigurableEnvironment environment = applicationContext.getEnvironment();
        MapPropertySource propertySource = new MapPropertySource("customStart", createCustomProperties());
        environment.getPropertySources().addLast(propertySource);
    }
 
    private Map<String, Object> createCustomProperties() {
        Map<String, Object> customProperties = new HashMap<>();
        // 添加自定义属性
        customProperties.put("custom.property.key", "customPropertyValue");
        return customProperties;
    }
}

要使用这个自定义的ApplicationContextInitializer，你需要在Spring Boot应用的main方法中传递它：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class CustomStartApplication {
 
    public static void main(String[] args) {
        SpringApplication app = new SpringApplication(CustomStartApplication.class);
        app.addInitializers(new CustomStartApplicationContextInitializer());
        app.run(args);
    }
}

在这个例子中，CustomStartApplicationContextInitializer会在应用上下文初始化时向环境中添加一些自定义的属性。这些属性可以在Spring Boot的任何配置中使用，比如application.properties、application.yml或者通过@Value注解。