修改如下：（一共三个地方）
package cn.dadongzicool.coin.entities;

import java.util.Random;

public class Coin {
   
    private int coinNumber;
    private int inputNumber;
    private int takeNumber;
   
    Random random;
   
    //public void getCoinSide(){
        //System.out.println("Coin's getCoinSide");
    //}
   
    public void setCoinNum(){
        random = new Random();
        coinNumber = random.nextInt(10)+30;
    }
   
    public int getCoinNum(){
        System.out.println("Coin's getCoinNum");
        return coinNumber;
    }
   
    public boolean takeCoin(int takeCoinNumber){
        System.out.println("Coin's takeCoin");
        if(takeCoinNumber <= coinNumber){
            coinNumber -=takeCoinNumber;
            return true;
        }
        else
            return false;
    }
   
    public boolean getWinner(){
        System.out.println("Coin's getWinner");
        if(coinNumber == 0){   //把此处的判断由coinNumber == 1改为coinNumber == 0
            return true;
        }
        return false;
    }

}
***********************************************
package cn.dadongzicool.coin.controller;

import java.util.Random;

import cn.dadongzicool.coin.entities.Coin;
import cn.dadongzicool.coin.view.GamePanel;

public class Controller {
   
    Coin coin;

    Random random = new Random();
   
    int inputNumber;

    public Controller(Coin coin){
        this.coin = coin;
    }
   
    public void newGame(){
        coin.setCoinNum();
    }
   
    public void chargeOfEnter(){
        if(!coin.getWinner()){
            try{
            inputNumber = Integer.parseInt(GamePanel.inputTextField.getText().trim());
            }
            catch(Exception ee){
                GamePanel.showTextArea.append("\n"+ee+"\n");
            }
            if(inputNumber <=0 || inputNumber > 3){
                GamePanel.showTextArea.append("Please enter a number between 1 to 3 !!!\n");
            }
            else{
                if(coin.takeCoin(inputNumber)){
                    GamePanel.showTextArea.append("user take  "+inputNumber+"  coins!\n" +
                            "There are  "+coin.getCoinNum()+"  left!\n");
                    if(coin.getWinner()){
                        GamePanel.showTextArea.append("Winner:Computer!!!\n");");//此处的：User改为Computer
                    }
            int computerTakeCoinNum = 0;
            if(coin.getCoinNum() > 4) {
                computerTakeCoinNum = random.nextInt(3)+1;
            }
            else {
                computerTakeCoinNum = coin.getCoinNum()-1;
                if(computerTakeCoinNum ==0 ){
                    computerTakeCoinNum++;
                }
            }
            if(!coin.getWinner()){
                coin.takeCoin(computerTakeCoinNum);
                GamePanel.showTextArea.append("computer take  "+computerTakeCoinNum+"  coins!\n" +
                        "There are  "+coin.getCoinNum()+"  left!\n");
                if(coin.getWinner()){
                    GamePanel.showTextArea.append("Winner:User!!!\n");//此处的Winner：computer改为User
                }
            }
        }
        else{
            GamePanel.showTextArea.append("Sorry,there is only  "+coin.getCoinNum()+"  left!\n" +
                    "Please enter a number which is lower than  "+coin.getCoinNum()+"  !\n");
        }
        }
    }
    }

}

令导出的jar文件：

真是难……我是初学者

高手真多啊……

我也是才开始接触JAVA呢 可感觉吧  太难了  可能是自己没用功吧  自己还是要加油啊
谢了

面向过程

发现一个问题 关于布局的

改变窗口大小时