java getEnv不区分大小写 getProperty区分大小写

System.out.println(System.getenv("JAVA_HOME"));  
System.out.println(System.getenv("Path"));  
System.out.println(System.getenv("PATH"));//不区分大小写
System.out.println(System.getenv("Tmp"));  

System.out.println("-------------------------------------");  
System.out.println(System.getProperty("os.name"));  
System.out.println(System.getProperty("OS.NAME"));//区分大小写
System.out.println(System.getProperty("temp"));  
System.out.println(System.getProperties());