helloworld.java

Java程序设计实验与实训源代码经典的JAVA学习教材

//NotHelloWorld.java
//图形界面的字符输入
import javax.swing.*;
import java.awt.*;

public class HelloWorld
{  
   public static void main(String[] args)
   {  
      HelloWorldFrame frame = new HelloWorldFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.show();
   }
}

//包含信息面板的框架
 
class HelloWorldFrame extends JFrame
{
   public HelloWorldFrame()
   {
      setTitle("世界你好");
      setSize(WIDTH, HEIGHT);

      // 添加面板到框架

      HelloWorldPanel panel = new HelloWorldPanel();
      Container contentPane = getContentPane();
      contentPane.add(panel);
   }

   public static final int WIDTH = 300;        //文本框的宽度
   public static final int HEIGHT = 200;       //文本框的高度
}

//定义显示信息的面版
  
class HelloWorldPanel extends JPanel
{  
   public void paintComponent(Graphics g)
   {  
      super.paintComponent(g);

      g.drawString("世界，你好", 
         MESSAGE_X, MESSAGE_Y);
   }

   public static final int MESSAGE_X = 75;     //输出信息的组件的左上角x坐标
   public static final int MESSAGE_Y = 100;    //输出信息的组件的左上角y坐标
}