java内部精髓 java的精髓是什么

HelloJava 
    
import javax.swing.JOptionPane;
//jdk1.6后支持系统拖盘
public class HelloJava { /**
  * @param args
  */
 private static String say="我要学会你。";
 public static void main(String[] args) {
  // TODO Auto-generated method stub
         System.out.println("Hello Java");
         System.out.println("你好 Java"+ say);
       //弹出对话框
   JOptionPane.showMessageDialog(null,"弹出对话框。");
   
     String version =  System.getProperty( "java.version");
     System.out.println(version);
     JOptionPane.showMessageDialog(null,"Java JDK版本：" + version);
 }
}