import java.awt.Color;

import java.awt.Component;

import java.awt.Container;

import java.awt.Graphics;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.SwingConstants;

import javax.swing.WindowConstants;

public class Test implements Lcon {

private int width;

private int height;

public int getLconHeight() {

return this.height;

}

public int getLconwidth() {

return this.width;

}

public Test(int width, int height) {

this.width = width;

this.height = height;

}

// 实现paintLcon()方法

public void paintLcon(Component arg0, Graphics arg1, int x, int y) {

arg1.fillOval(x, y, width, height); // 绘制一个圆形

}

public static void main(String[] args) {

Test icon = new Test(15, 15);

JLabel j = new JLabel("测试", icon, SwingConstants.CENTER);

JFrame jf = new JFrame();

Container c = jf.getContentPane();

c.setBackground(Color.black);

jf.setVisible(true);

jf.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

}

}

JLabel j = new JLabel("测试", icon, SwingConstants.CENTER);

提示   构造函数 JLabel（String, Test, int）未定义 

请问原因, 以及 分开书写的方式.

第二个问题 , public class Test implements Lcon  

会提示没有创建Lcon创建接口,书上没有提, 直接按照提示创建了一个Lcon的接口  是否是一样的?