用Java编写的http下载工具类，包含下载进度回调

柔光的暖阳◎ 2022-01-05 16:55 226阅读 0赞

HttpDownloader.java

package com.buyishi;
    
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.net.URL;
    import java.net.URLConnection;
    
    public class HttpDownloader {
    
        private final String url, destFilename;
    
        public HttpDownloader(String url, String destFilename) {
            this.url = url;
            this.destFilename = destFilename;
        }
    
        public void download(Callback callback) {
            try (FileOutputStream fos = new FileOutputStream(destFilename)) {
                URLConnection connection = new URL(url).openConnection();
                long fileSize = connection.getContentLengthLong();
                InputStream inputStream = connection.getInputStream();
                byte[] buffer = new byte[10 * 1024 * 1024];
                int numberOfBytesRead;
                long totalNumberOfBytesRead = 0;
                while ((numberOfBytesRead = inputStream.read(buffer)) != - 1) {
                    fos.write(buffer, 0, numberOfBytesRead);
                    totalNumberOfBytesRead += numberOfBytesRead;
                    callback.onProgress(totalNumberOfBytesRead * 100 / fileSize);
                }
                callback.onFinish();
            } catch (IOException ex) {
                callback.onError(ex);
            }
        }
    
        public interface Callback {
    
            void onProgress(long progress);
    
            void onFinish();
    
            void onError(IOException ex);
        }
    }

OkHttpDownloader.java  //基于OkHttp

package com.buyishi;
    
    import java.io.BufferedInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    import okhttp3.OkHttpClient;
    import okhttp3.Request;
    import okhttp3.ResponseBody;
    
    public class OkHttpDownloader {
    
        private final String url, destFilename;
        private static final Logger LOGGER = Logger.getLogger(OkHttpDownloader.class.getName());
    
        public OkHttpDownloader(String url, String destFilename) {
            this.url = url;
            this.destFilename = destFilename;
    
        }
    
        public void download(Callback callback) {
            BufferedInputStream input = null;
            try (FileOutputStream fos = new FileOutputStream(destFilename)) {
                Request request = new Request.Builder().url(url).build();
                ResponseBody responseBody = new OkHttpClient().newCall(request).execute().body();
                long fileSize = responseBody.contentLength();
                input = new BufferedInputStream(responseBody.byteStream());
                byte[] buffer = new byte[10 * 1024 * 1024];
                int numberOfBytesRead;
                long totalNumberOfBytesRead = 0;
                while ((numberOfBytesRead = input.read(buffer)) != - 1) {
                    fos.write(buffer, 0, numberOfBytesRead);
                    totalNumberOfBytesRead += numberOfBytesRead;
                    callback.onProgress(totalNumberOfBytesRead * 100 / fileSize);
                }
                callback.onFinish();
            } catch (IOException ex) {
                callback.onError(ex);
            } finally {
                if (input != null) {
                    try {
                        input.close();
                    } catch (IOException ex) {
                        LOGGER.log(Level.SEVERE, null, ex);
                    }
                }
            }
        }
    
        public interface Callback {
    
            void onProgress(long progress);
    
            void onFinish();
    
            void onError(IOException ex);
        }
    }

MainFrame.java  //对两个工具类的测试

package com.buyishi;
    
    import java.awt.GridLayout;
    import java.awt.event.MouseAdapter;
    import java.awt.event.MouseEvent;
    import java.io.IOException;
    import java.util.logging.Level;
    import java.util.logging.Logger;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    
    public class MainFrame extends JFrame {
    
        private final JButton test1Button, test2Button;
        private static final Logger LOGGER = Logger.getLogger(MainFrame.class.getName());
    
        private MainFrame() {
            super("Download Test");
            super.setSize(300, 200);
            super.setLocationRelativeTo(null);
            super.setDefaultCloseOperation(EXIT_ON_CLOSE);
            super.setLayout(new GridLayout(2, 1));
            test1Button = new JButton("测试1");
            test2Button = new JButton("测试2");
            super.add(test1Button);
            super.add(test2Button);
            test1Button.addMouseListener(new MouseAdapter() {
                private boolean downloadStarted;
    
                @Override
                public void mouseClicked(MouseEvent e) {
                    if (!downloadStarted) {
                        downloadStarted = true;
                        new Thread() {
                            @Override
                            public void run() {
                                String url = "http://download.microsoft.com/download/A/C/9/AC924EA1-9F39-4DFD-99DF-2C1DEB922174/EIE11/WOL/EIE11_ZH-CN_WOL_WIN764.EXE";
    //                            String url = "https://dl.360safe.com/drvmgr/360DrvMgrInstaller_net.exe";
                                new HttpDownloader(url, "C:/Users/BuYishi/Desktop/file1").download(new HttpDownloader.Callback() {
                                    @Override
                                    public void onProgress(long progress) {
                                        LOGGER.log(Level.INFO, "{0}", progress);
                                        test1Button.setText("Downloading..." + progress + "%");
                                    }
    
                                    @Override
                                    public void onFinish() {
                                        LOGGER.log(Level.INFO, "Download finished");
                                        test1Button.setText("Downloaded");
                                    }
    
                                    @Override
                                    public void onError(IOException ex) {
                                        LOGGER.log(Level.SEVERE, null, ex);
                                        downloadStarted = false;
                                    }
                                });
                            }
                        }.start();
                    }
                }
            });
            test2Button.addMouseListener(new MouseAdapter() {
                private boolean downloadStarted;
    
                @Override
                public void mouseClicked(MouseEvent e) {
                    if (!downloadStarted) {
                        downloadStarted = true;
                        new Thread() {
                            @Override
                            public void run() {
                                String url = "http://download.microsoft.com/download/A/C/9/AC924EA1-9F39-4DFD-99DF-2C1DEB922174/EIE11/WOL/EIE11_ZH-CN_WOL_WIN764.EXE";
    //                            String url = "https://dl.360safe.com/drvmgr/360DrvMgrInstaller_net.exe";
                                new OkHttpDownloader(url, "C:/Users/BuYishi/Desktop/file2").download(new OkHttpDownloader.Callback() {
                                    @Override
                                    public void onProgress(long progress) {
                                        test2Button.setText("Downloading..." + progress + "%");
                                    }
    
                                    @Override
                                    public void onFinish() {
                                        test2Button.setText("Downloaded");
                                    }
    
                                    @Override
                                    public void onError(IOException ex) {
                                        LOGGER.log(Level.SEVERE, null, ex);
                                        downloadStarted = false;
                                    }
                                });
                            }
                        }.start();
                    }
                }
            });
        }
    
        public static void main(String[] args) {
            MainFrame frame = new MainFrame();
            frame.setVisible(true);
        }
    }

转载于:https://www.cnblogs.com/buyishi/p/9379930.html