Question

我有一些Java，从理论上讲，它从500x500窗口的左上角到右下角绘制一条线。代码：

import javax.swing.JComponent;
import javax.swing.JFrame;

import java.awt.*;
import java.awt.geom.*;

@SuppressWarnings("serial")

public class graphix extends JFrame{

    public static void main(String[] args){

        new graphix();
    }

    public graphix(){

        this.setSize(500, 500);

        this.setTitle("Title Here");

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        this.add(new Draw(), BorderLayout.CENTER);

        this.setVisible(true);

    }


    private class Draw extends JComponent{

        public void paint(Graphics g){

            Graphics2D graph2 = (Graphics2D)g;

            graph2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

            Shape drawLine = new Line2D.Float(10, 10, 490, 490);

            graph2.setPaint(Color.BLACK);

            graph2.draw(drawLine);

        }

    }

}

当我运行此代码时，eclipse会给我错误：

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 

at graphix.graphix.main(graphix.java:11)

通常在eclipse中，错误消息将显示在这两行之间的空白区域中，但它表示错误是在第11行触发的，这是

public static void main(String[] args){

我的项目名称是graphix，类文件名是graphix.java

修改

还有一个非致命错误：

The declared package "" does not match the expected package "graphix"

触发：

import javax.swing.JComponent;

Answer 1

文件顶部缺少包声明，它必须与项目中的文件结构匹配：

package xxx.yyy.zzz;

Eclipse Oxygen Java给出了空错误

1 个答案: