Android 文件下载工具类

ゝ一纸荒年。 2022-01-16 15:33 360阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

Android 文件下载工具类：

/**
     * Alipay.com Inc.
     * Copyright (c) 2005-2009 All Rights Reserved.
     */
    package com.alipay.android.appDemo4;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    
    import javax.net.ssl.SSLException;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.HttpStatus;
    import org.apache.http.client.HttpClient;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.DefaultHttpClient;
    
    import android.annotation.SuppressLint;
    import android.os.Handler;
    import android.os.Looper;
    import android.os.Message;
    
    /**
     * 文件下载类，支持断电续传
     * 
     * @author jianmin.jiang
     * 
     * @version $Id: FileDownloader.java, v 0.1 2012-2-14 下午8:41:05 jianmin.jiang
     *          Exp $
     */
    @SuppressLint("HandlerLeak")
    public final class FileDownloader {
    
        private String fileUrl;
        private String savePath;
        private String tmpPath;
        private FileDownloader.IDownloadProgress progressOutput;
        private FileFetch fetch;
        private boolean showProgress;
    
        public FileDownloader() {
            showProgress = false;
        }
    
        public FileDownloader(boolean showProgress) {
            this.showProgress = showProgress;
        }
    
        /**
         * @param fileUrl
         *            文件下载链接地址
         */
        public final void setFileUrl(String fileUrl) {
            this.fileUrl = fileUrl;
        }
    
        public final void setShowProgress(boolean showProgress) {
            this.showProgress = showProgress;
        }
    
        protected final boolean showProgress() {
            return this.showProgress;
        }
    
        /**
         * @param savePath
         *            文件保存地址，使用绝对路径
         */
        public final void setSavePath(String savePath) {
            this.savePath = savePath;
            this.tmpPath = savePath + ".tmp";
        }
    
        /**
         * @param progressOutput
         *            下载进度输出类
         */
        public final void setProgressOutput(FileDownloader.IDownloadProgress progressOutput) {
            if (progressOutput != null) {
                this.progressOutput = progressOutput;
            }
        }
    
        public void start() {
            final ProgressOutput output = new ProgressOutput(Looper.getMainLooper());
            new Thread(new Runnable() {
    
                public void run() {
                    fetch = new FileFetch(fileUrl, savePath, FileDownloader.this);
                    long fileLen = -1;
                    if (showProgress) {
                        fileLen = getFileSize();
                        if (fileLen <= 0) {
                            output.sendEmptyMessage(0);
                            return;
                        }
                    } else {
                        deleteFile();
                    }
                    if (showProgress) {
                        readTempFile();
                        if (fetch.getFileEnd() != fileLen) {
                            deleteFile();
                            fetch.setFileStart(0);
                            fetch.setFileEnd(fileLen);
                        }
                    }
                    new Thread(fetch).start();
                    output.isFinished = false;
                    while (!fetch.isStop()) {
                        try {
                            Thread.sleep(1500);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        output.sendEmptyMessage(0);
                    }
                    output.sendEmptyMessage(0);
                }
            }).start();
        }
    
        public void stop() {
    
            fetch.stop();
        }
    
        private long getFileSize() {
            long fileLength = -1;
            try {
                HttpEntity entity = getHttpEntity(fileUrl, false);
                fileLength = entity.getContentLength();
            } catch (Exception e) {
                // AppErrorException.printException(this.getClass(),
                // "can not get file length", e);
                e.printStackTrace();
            }
            return fileLength;
        }
    
        private void deleteFile() {
            File file = new File(savePath);
            if (file.exists()) {
                file.delete();
            }
            file = new File(tmpPath);
            if (file.exists()) {
                file.delete();
            }
        }
    
        protected void writeTempFile() {
            FileOutputStream out = null;
            ObjectOutputStream objOut = null;
            try {
                out = new FileOutputStream(this.tmpPath);
                objOut = new ObjectOutputStream(out);
                objOut.writeLong(fetch.getFileStart());
                objOut.writeLong(fetch.getFileEnd());
                objOut.flush();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    out.close();
                } catch (Exception e) {
                }
                try {
                    objOut.close();
                } catch (Exception e) {
                }
            }
        }
    
        private void readTempFile() {
            FileInputStream in = null;
            ObjectInputStream objIn = null;
            try {
                in = new FileInputStream(this.tmpPath);
                objIn = new ObjectInputStream(in);
                fetch.setFileStart(objIn.readLong());
                fetch.setFileEnd(objIn.readLong());
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    in.close();
                } catch (Exception e) {
                }
                try {
                    objIn.close();
                } catch (Exception e) {
                }
            }
        }
    
        public static HttpEntity getHttpEntity(String netAddress, boolean isZip) throws Exception {
            try {
                // HttpGet连接对象
                HttpGet httpGet = new HttpGet(netAddress);
                // 取得HttpClient
                HttpClient httpClient = new DefaultHttpClient();
                if (isZip) {
                    httpGet.addHeader("Accept-Encoding", "gzip");
                }
                // 请求HttpClient，获得HttpResponce
                HttpResponse response = httpClient.execute(httpGet);
                // 请求成功
                int code = response.getStatusLine().getStatusCode();
                if (code == HttpStatus.SC_OK) {
                    HttpEntity entity = response.getEntity();
                    return entity;
                } else {
                    throw new Exception("net work exception,ErrorCode :" + code);
                }
            } catch (SSLException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    
        private class ProgressOutput extends Handler {
    
            private boolean isFinished;
    
            @SuppressLint("HandlerLeak")
            public ProgressOutput(Looper looper) {
                super(looper);
                isFinished = false;
            }
    
            @Override
            public void handleMessage(Message msg) {
                if (progressOutput == null) {
                    return;
                }
                if (progressOutput == null) {
                    return;
                }
                try {
                    float progress = 50;
                    if (showProgress) {
                        progress = ((fetch.getFileStart() * 100) / fetch.getFileEnd());
                    } else if (fetch.isStop()) {
                        progress = 100;
                    }
    
                    if (fetch.isStop()) {
                        if (progress == 100 && !isFinished) {
                            progressOutput.downloadSucess();
                            isFinished = true;
                        } else if (progress > 100) {
                            deleteFile();
                            progressOutput.downloadFail();
                        } else if (!isFinished) {
                            progressOutput.downloadFail();
                        }
                    } else {
                        progressOutput.downloadProgress(progress);
                    }
                } catch (Exception e) {
                    progressOutput.downloadFail();
                }
            }
        }
    
        public interface IDownloadProgress {
    
            void downloadProgress(float progress);
    
            void downloadSucess();
    
            void downloadFail();
    
        }
    
    }

转载于:https://my.oschina.net/u/2320057/blog/635313

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220114/787d9fef028440c2bb09fd9576119b26.png