1、利用线程模拟文件复制的进度显示,如下图所示,点击“复制文件”,开始显示进度条,并实时显示复制进度,复制完成后显示“文件复制已完成!”,点击“取消”,取消复制,进度条归零,点击“×”可以退出系统,注意复制按钮和取消按钮在同一时间,只有一个可用。

 

package com;

import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class WelcomeJFrame extends JFrame {
    public WelcomeJFrame(){
        super("实验八多线程 文件复制进度条演示");
        this.setBounds(300,240,400,300);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);

        this.setLayout(new GridLayout(4,1));

        JButton jb1 = new JButton();
        jb1.setText("确认");
        JButton jb2 = new JButton();
        jb2.setText("取消");
        if(jb2.isEnabled()){
            jb1.setEnabled(false);
        }
        if(jb1.isEnabled()){
            jb2.setEnabled(false);
        }
        this.add(jb1,BorderLayout.NORTH);
        this.add(jb2);

        JLabel jLabel= new JLabel();
        this.add(jLabel);
        jLabel.setText("文件复制0%");
        final int[] currentProgress = {0};
        final JProgressBar progressBar = new JProgressBar();
        final int MIN_PROGRESS = 0;
        final int MAX_PROGRESS = 100;
        Timer timer = new Timer(50, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                currentProgress[0]++;
                if (currentProgress[0] > MAX_PROGRESS) {
                    currentProgress[0] = MIN_PROGRESS;
                }
                jLabel.setText("文件复制"+currentProgress[0]+"%");
                progressBar.setValue(currentProgress[0]);
            }
        });

        jb1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                jb2.setEnabled(true);
                jb1.setEnabled(false);
                timer.start();
            }
        });
        jb2.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                jb1.setEnabled(true);
                jb2.setEnabled(false);
                currentProgress[0]=0;
                jLabel.setText("文件复制"+currentProgress[0]+"%");
                progressBar.setValue(currentProgress[0]);
                timer.start();
                timer.stop();

            }
        });


        progressBar.setMinimum(MIN_PROGRESS);
        progressBar.setMaximum(MAX_PROGRESS);
        progressBar.setStringPainted(true);

        progressBar.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {
                System.out.println("当前进度值: " + progressBar.getValue() + "; " +
                        "进度百分比: " + progressBar.getPercentComplete());
            }
        });
        progressBar.setValue(currentProgress[0]);


        // 添加到内容面板
        this.add(progressBar);
        this.setVisible(true);
    }

    public static void main(String[] args) {
        new WelcomeJFrame();


        CopyFile cf1 = new CopyFile("C:\\Users\\hx\\Videos\\COPY\\hang1.txt", "C:\\Users\\hx\\Videos\\COPY\\hang2.txt");
        cf1.start();
    }
}
package com;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.DecimalFormat;

public class CopyFile extends Thread {

    public File older;// 源文件路径
    public File newer;// 复制目标路径

    public CopyFile(String older, String newer) {
        this.older = new File(older);
        this.newer = new File(newer);
    }



    @Override
    public void run() {

        FileInputStream fis = null;
        FileOutputStream fos = null;

        try {
            fis = new FileInputStream(older);
            fos = new FileOutputStream(newer);

            byte[] b = new byte[1024];// 声明一个字节数组,每次读取的数据存到该字节数组里
            int length = 0;// 返回每次读取的数据长度
            long len = older.length();// 获取源文件的长度
            double temp = 0;
            DecimalFormat df = new DecimalFormat("##%");

            while ((length = fis.read(b)) != -1) {
                fos.write(b, 0, length);// 把每次读取的内容,输出到目标路径文件中
                temp += length;// 把每次读取的数据长度累加
                double d = temp / len;// 计算出已经读取的长度占文件总长度的比率
                int jd = (int) d;
                if (jd % 10 == 0) {

                    System.out.println(older.getName() + "文件复制了:" + df.format(d));

                }

            }

            System.out.println(older.getName() + "复制完毕!");
        } catch (IOException e) {

            e.printStackTrace();

        } finally {
            try {

                fis.close();
                fos.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }



    }

}
package com;

import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class WelcomeJFrame extends JFrame {
    public WelcomeJFrame(){
        super("实验八多线程 文件复制进度条演示");
        this.setBounds(300,240,400,300);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);

        this.setLayout(new GridLayout(4,1));

        JButton jb1 = new JButton();
        jb1.setText("确认");
        JButton jb2 = new JButton();
        jb2.setText("取消");
        if(jb2.isEnabled()){
            jb1.setEnabled(false);
        }
        if(jb1.isEnabled()){
            jb2.setEnabled(false);
        }
        this.add(jb1,BorderLayout.NORTH);
        this.add(jb2);

        JLabel jLabel= new JLabel();
        this.add(jLabel);
        jLabel.setText("文件复制0%");
        final int[] currentProgress = {0};
        final JProgressBar progressBar = new JProgressBar();
        final int MIN_PROGRESS = 0;
        final int MAX_PROGRESS = 100;
        Timer timer = new Timer(50, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                currentProgress[0]++;
                if (currentProgress[0] > MAX_PROGRESS) {
                    currentProgress[0] = MIN_PROGRESS;
                }
                jLabel.setText("文件复制"+currentProgress[0]+"%");
                progressBar.setValue(currentProgress[0]);
            }
        });

        jb1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                jb2.setEnabled(true);
                jb1.setEnabled(false);
                timer.start();
            }
        });
        jb2.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                jb1.setEnabled(true);
                jb2.setEnabled(false);
                currentProgress[0]=0;
                jLabel.setText("文件复制"+currentProgress[0]+"%");
                progressBar.setValue(currentProgress[0]);
                timer.start();
                timer.stop();

            }
        });


        progressBar.setMinimum(MIN_PROGRESS);
        progressBar.setMaximum(MAX_PROGRESS);
        progressBar.setStringPainted(true);

        progressBar.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent e) {
                System.out.println("当前进度值: " + progressBar.getValue() + "; " +
                        "进度百分比: " + progressBar.getPercentComplete());
            }
        });
        progressBar.setValue(currentProgress[0]);


        // 添加到内容面板
        this.add(progressBar);
        this.setVisible(true);
    }

    public static void main(String[] args) {
        new WelcomeJFrame();


        CopyFile cf1 = new CopyFile("C:\\Users\\hx\\Videos\\COPY\\hang1.txt", "C:\\Users\\hx\\Videos\\COPY\\hang2.txt");
        cf1.start();
    }
}