1.界面+文件输入输出流

package finalExam;

import java.awt.BorderLayout;

import java.awt.Container;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.Writer;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JTextArea;

public class FrameAndFile extends JFrame implements ActionListener{

    String default_save_file_name="myTxT.txt";

    JTextArea jTextArea;//用户输入框

    JButton jButton_read,jButton_save,jButton_clear;//两个Button

    public FrameAndFile() {

        //界面设置

        setTitle("记事本");

        Container container=getContentPane();

        container.setLayout(new BorderLayout());

        setLocation(200,300);

        jTextArea=new JTextArea(30,80);

        jTextArea.setLineWrap(true); //激活自动换行功能

        jTextArea.setWrapStyleWord(true);//换行不断字

        container.add("North",jTextArea);

        JPanel jPanel_button_area=new JPanel(new GridLayout(1,3));

        jButton_read=new JButton("读取");

        jButton_clear=new JButton("清空");

        jButton_save=new JButton("保存");

        jPanel_button_area.add(jButton_save);

        jPanel_button_area.add(jButton_clear);

        jPanel_button_area.add(jButton_read);

        jButton_clear.addActionListener(this);

        jButton_read.addActionListener(this);

        jButton_save.addActionListener(this);

        container.add("Center",jPanel_button_area);

        pack();

        setVisible(true);

        setDefaultCloseOperation(EXIT_ON_CLOSE);

    }

    public static void main(String[] args) {

        new FrameAndFile();

    }

    @Override

    public void actionPerformed(ActionEvent e) {

        switch (e.getActionCommand()) {

        case "清空":

            jTextArea.setText("");

            break;

        case "保存":

            save();

            break;

        case "读取":

            read();

            break;

        default:

            break;

        }

    }

    /**

     * 文件读取

     * 使用FileReader+BufferedReader

     * */

    public void read() {

        FileReader fileReader=null;

        BufferedReader bufferedReader=null;

        File file=new File(default_save_file_name);

        if(file.exists()) {

            try {

                fileReader=new FileReader(file);

                bufferedReader=new BufferedReader(fileReader);

                String input_str="";

                while(bufferedReader.ready()) {

                    input_str=input_str+bufferedReader.readLine();

                }

                jTextArea.setText(input_str);

            } catch (FileNotFoundException e) {

                showErrorMessage("出错了:"+e);

                e.printStackTrace();

            } catch (IOException e) {

                showErrorMessage("出错了:"+e);

                e.printStackTrace();

            }finally {

                try {

                    bufferedReader.close();

                    fileReader.close();

                } catch (IOException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

        }else {

            showErrorMessage("文件不存在！");

        }

    }

    /**

     * 文件保存

     * 使用FileWriter

     * */

    public void save() {

        Writer writer=null;

        File file=new File(default_save_file_name);

        try {

            writer=new FileWriter(file,true);

            String string=jTextArea.getText();

            if(string!=null||!string.equals("")){

                writer.write(string);

                writer.flush();

                showMessage("保存成功");

            }else {

                showErrorMessage("请输入完整！");

            }

        } catch (IOException e) {

            showErrorMessage("出错了："+e);

            e.printStackTrace();

        }finally {

            try {

                writer.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

    public void showMessage(String message) {

        JOptionPane.showMessageDialog(null, message);

    }

    public void showErrorMessage(String message) {

        JOptionPane.showMessageDialog(null, message, "警告",

                JOptionPane.WARNING_MESSAGE);

    }

}

2..编写选号程序，在窗体中安排6个标签，每个标签上显示0-9之间的一位数字，每位数字用一个线程控制其变化，单击“停止”按钮则所有标签数字停止变化。（多线程）

package finalExam;

import java.awt.BorderLayout;

import java.awt.Container;

import java.awt.FlowLayout;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import java.util.Random;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

public class MultiplyThread extends JFrame{

    //自定义一个类，负责封装所有控件的操作

    RandomPanelManager randomPanelManager;

    //主类只负责界面操作

    public MultiplyThread() {

        setTitle("抽号");

        Container container=getContentPane();

        container.setLayout(new FlowLayout());

        setBounds(200,300,300,350);

        randomPanelManager=new RandomPanelManager();

        container.add(randomPanelManager.getCom());

        setVisible(true);

        setDefaultCloseOperation(EXIT_ON_CLOSE);

    }

    //管理类

    class RandomPanelManager implements ActionListener{

        List<MyLable> lables;//用来存放6个MyLable

        JPanel jPanel;//封装在一个大的JPanel中

        public RandomPanelManager() {

            lables=new ArrayList<MultiplyThread.MyLable>();

            jPanel=new JPanel(new GridLayout(7,1,10,10));

            for(int i=0;i<6;i++) {

                MyLable myLable=new MyLable();

                lables.add(myLable);

                jPanel.add(myLable);

            }

            JPanel jPanel_buttonJPanel=new JPanel(new GridLayout(1,2));

            JButton jButton_startButton=new JButton("开始");

            JButton jButton_endButton=new JButton("停止");

            jButton_endButton.addActionListener(this);

            jButton_startButton.addActionListener(this);

            jPanel_buttonJPanel.add(jButton_startButton);

            jPanel_buttonJPanel.add(jButton_endButton);

            jPanel.add(jPanel_buttonJPanel);

        }

        public JPanel getCom() {

            return jPanel;

        }

        @Override

        public void actionPerformed(ActionEvent e) {

            switch (e.getActionCommand()) {

            case "开始":

                start();

                break;

            case "停止":

                stop();

                break;

            default:

                break;

            }

        }

        /**

         * 开始随机数

         * 注意需要先把flag置为true

         * 再创建Thread并放入运行

         * */

        public void start() {

            for (MyLable item:lables) {

                item.init();

                Thread thread=new Thread(item);

                thread.start();

            }

        }

        /**

         * 停止随机数

         * 只需要把flag置false即可

         * */

        public void stop() {

            for (MyLable item:lables) {

                item.stop();

            }

        }

    }

    //自定义控件，实现Runnable接口

    class MyLable extends JPanel implements Runnable{

        JLabel jLabel_tag;

        boolean flag=true;

        public MyLable() {

            jLabel_tag=new JLabel("0");

            this.setLayout(new FlowLayout());

            this.add(jLabel_tag);

        }

        public void setText() {

            jLabel_tag.setText(getRandomNum()+"");

        }

        /**

         * 获取随机数

         * 种子为：当前时间

         * 范围[0-9]

         * */

        public int getRandomNum(){

            Date date=new Date();

            Random random=new Random(date.getTime());//随机种子

            return random.nextInt(10);

        }

        @Override

        public void run() {

            while(flag) {

                setText();

            }

        }

        public void stop() {

            flag=false;

        }

        /**

         * 恢复，考虑到重复执行的情况

         * */

        public void init() {

            flag=true;

        }

    }

    public static void main(String[] args) {

        new MultiplyThread();

    }

}

3.异常处理从键盘输入一个正整数，判断是否为偶数，不是则抛出异常

package finalExam;

import java.util.Scanner;

import java.util.regex.Pattern;

public class MyException extends RuntimeException {

    private static final long serialVersionUID = 123456789L;

        public MyException() {

        super();

        // TODO Auto-generated constructor stub

    }

    public MyException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {

        super(message, cause, enableSuppression, writableStackTrace);

        // TODO Auto-generated constructor stub

    }

    public MyException(String message, Throwable cause) {

        super(message, cause);

        // TODO Auto-generated constructor stub

    }

    public MyException(String message) {

        super(message);

        // TODO Auto-generated constructor stub

    }

    public MyException(Throwable cause) {

        super(cause);

        // TODO Auto-generated constructor stub

    }

    public static void main(String[] args) {

        Scanner scanner=null;

        try {

            System.out.println("请输入一个整数并继续：");

            scanner=new Scanner(System.in);

            String inputstr=scanner.nextLine();

            if(isNumeric(inputstr)) {

                Integer a=Integer.parseInt(inputstr);

                if(a<0) {

                    throw new MyException("不是正整数");

                }

                if(a%2!=0) {

                    throw new MyException("不是偶数");

                }

                System.out.println("输入成功！");

            }else {

                throw new MyException("不是整数");

            }

        } catch (Exception e) {

            e.printStackTrace();

        }finally {

            scanner.close();

        }

    }

    /**

     * 通过正则判断字符串是否为整数

     * 这个是我考虑的比较多的，可以直接不用判断

     * 在主函数中使用Scanner.nextInt

     * 如果输入不是整数会自动抛出异常

     * */

    public static boolean isNumeric(String string){

        Pattern pattern = Pattern.compile("[0-9]*");

        return pattern.matcher(string).matches();

    }

}

巴特西

【Java】实验代码整理（多线程、自定义异常、界面）

1.界面+文件输入输出流

2..编写选号程序，在窗体中安排6个标签，每个标签上显示0-9之间的一位数字，每位数字用一个线程控制其变化，单击“停止”按钮则所有标签数字停止变化。（多线程）

3.异常处理从键盘输入一个正整数，判断是否为偶数，不是则抛出异常

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