我有一個(gè)包含兩個(gè)類的 MyFirst 程序.java文件。我剛剛修改了路徑，并嘗試使用和測試文件。javajavacpublic class MyFirstProgram{    public static void main(String[] args){        System.out.println("Hello ! World :)");    }}但是，它返回我：C:\Users\antoi\Documents\Programming\Julien>java MyFirstProgram.javaError: Could not find or load main class MyFirstProgram.javaC:\Users\antoi\Documents\Programming\Julien>javac MyFirstProgram.java'javac' is not recognized as an internal or external command,operable program or batch file.這是路徑：只有當(dāng)我直接在文件夾中調(diào)用javac時(shí)，它才有效：C:\Users\antoi\Documents\Programming\Julien>"C:\Program Files\Java\jdk-11.0.2\bin\javac" MyFirstProgram.javaC:\Users\antoi\Documents\Programming\Julien>java MyFirstProgramError: A JNI error has occurred, please check your installation and try againException in thread "main" java.lang.UnsupportedClassVersionError: MyFirstProgram has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0        at java.lang.ClassLoader.defineClass1(Native Method)        at java.lang.ClassLoader.defineClass(Unknown Source)        at java.security.SecureClassLoader.defineClass(Unknown Source)        at java.net.URLClassLoader.defineClass(Unknown Source)        at java.net.URLClassLoader.access$100(Unknown Source)        at java.net.URLClassLoader$1.run(Unknown Source)        at java.net.URLClassLoader$1.run(Unknown Source)        at java.security.AccessController.doPrivileged(Native Method)        at java.net.URLClassLoader.findClass(Unknown Source)        at java.lang.ClassLoader.loadClass(Unknown Source)        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)        at java.lang.ClassLoader.loadClass(Unknown Source)        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)然而，它無法顯示消息，并顯示有一個(gè) .我從其他帖子中了解到，這是我的Java運(yùn)行時(shí)環(huán)境，因?yàn)樗赡懿环厦?。要?zhí)行哪些步驟才能打印“你好世界”消息？javaUnsupportedClassVersionErrorjavacjava