Spring之底层架构核心概念Environment及用法详解

public static void main(String[] args) {

    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);

    //操作系统层面的环境变量
    Map<String, Object> systemEnvironment = context.getEnvironment().getSystemEnvironment();
    System.out.println(systemEnvironment);
    System.out.println("==========Environment==========");

    //java运行层面，通过-D指定的
    Map<String, Object> systemProperties = context.getEnvironment().getSystemProperties();
    System.out.println(systemProperties );
    System.out.println("=========Properties===========");

}

 Map<String, Object> systemProperties = context.getEnvironment().getSystemProperties(); 

MutablePropertySources sources = context.getEnvironment().getPropertySources();
System.out.println(sources);
System.out.println("=========MutablePropertySources===========");

//操作系统层面
System.out.println(context.getEnvironment().getProperty("JAVA_HOME"));
//指定环境变量
System.out.println(context.getEnvironment().getProperty("sun.jnu.encoding"));
//配置文件
System.out.println(context.getEnvironment().getProperty("zjy"));