android下多线程多任务下载，及断点续传

最新推荐文章于 2025-05-21 21:59:00 发布

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本文介绍如何使用FileDownloader库实现文件的单个和批量下载功能，并提供了详细的代码示例，包括进度回调、错误处理等关键步骤。

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使用了一个第三方库：filedownloader

引用

compile 'com.liulishuo.filedownloader:library:1.6.9'

使用：

//下载单个文件

public static void downloadSingleFile(String url, String savePath, Context context, final DownloadCallBack callBack){
        FileDownloader.setup(context);
        if(downloader == null){
            downloader = FileDownloader.getImpl();
        }
        downloader.pauseAll();
        downloader.setMaxNetworkThreadCount(15);
        downloader.create(url)
                .setPath(savePath).setAutoRetryTimes(2)
                .setListener(new FileDownloadLargeFileListener() {
                    @Override
                    protected void pending(BaseDownloadTask task, long soFarBytes, long totalBytes) {

                    }

                    @Override
                    protected void progress(BaseDownloadTask task, long soFarBytes, long totalBytes) {
                        callBack.onProgress((int)((float)soFarBytes/totalBytes*100),task.getSpeed());
                    }

                    @Override
                    protected void paused(BaseDownloadTask task, long soFarBytes, long totalBytes) {

                    }

                    @Override
                    protected void completed(BaseDownloadTask task) {
                        callBack.onCompleted(task.getTargetFilePath());
                    }

                    @Override
                    protected void error(BaseDownloadTask task, Throwable e) {
                        callBack.onFail(e.toString());
                    }

                    @Override
                    protected void warn(BaseDownloadTask task) {

                    }
                }).start();

    }

    private static int totalNum = 0;

//下载多个文件

public static void downloadMuiltyFiles(final List<String> urls, List<String> savePaths, Context context, final DownloadCallBack callBack){ if(urls == null || savePaths == null || urls.size() == 0 || urls.size() != savePaths.size()){ callBack.onCompleted(""); return; } final List<String> actUrls = new ArrayList<>(); List<String> actPaths = new ArrayList<>(); File file = null; int j = 0; for(String p:savePaths){ file = new File(p); if(!file.exists()){ actUrls.add(urls.get(j)); actPaths.add(p); } j++; } if(actPaths.size() == 0){ callBack.onCompleted(""); return; } FileDownloader.setup(context); totalNum = actUrls.size(); final FileDownloadListener downloadListener = new FileDownloadListener() { @Override protected void pending(BaseDownloadTask task, int soFarBytes, int totalBytes) { } @Override protected void connected(BaseDownloadTask task, String etag, boolean isContinue, int soFarBytes, int totalBytes) { } @Override protected void progress(BaseDownloadTask task, int soFarBytes, int totalBytes) { } @Override protected void blockComplete(BaseDownloadTask task) { } @Override protected void retry(final BaseDownloadTask task, final Throwable ex, final int retryingTimes, final int soFarBytes) { } @Override protected void completed(BaseDownloadTask task) { totalNum--;

		//多文件下载时，每下载一个文件，回调一次completed
                if(totalNum <= 0){
                    callBack.onCompleted(task.getTargetFilePath());
                }else{
                    int downNum = actUrls.size()-totalNum;
                    callBack.onNumProgress((int)((float)downNum/actUrls.size()*100),downNum,actUrls.size(),task.getSpeed());
                }
            }

            @Override
            protected void paused(BaseDownloadTask task, int soFarBytes, int totalBytes) {
            }

            @Override
            protected void error(BaseDownloadTask task, Throwable e) {
                callBack.onFail(e.toString());
            }

            @Override
            protected void warn(BaseDownloadTask task) {
            }
        };

        final FileDownloadQueueSet queueSet = new FileDownloadQueueSet(downloadListener);

        final List<BaseDownloadTask> tasks = new ArrayList<>();
        for (int i = 0; i < urls.size(); i++) {
            tasks.add(FileDownloader.getImpl().create(urls.get(i)).setPath(actPaths.get(i)).setTag(i + 1));
        }
       // 由于是队列任务, 这里是我们假设了现在不需要每个任务都回调`FileDownloadListener#progress`, 我们只关系每个任务是否完成, 所以这里这样设置可以很有效的减少ipc.
        queueSet.disableCallbackProgressTimes();
        // 所有任务在下载失败的时候都自动重试一次
        queueSet.setAutoRetryTimes(1);
        queueSet.downloadTogether(tasks);
        queueSet.start();

    }


    public interface DownloadCallBack{

        void onCompleted(String filename);

        void onProgress(int progress, int speed);

        void onNumProgress(int progress, int downNum, int totalNum, int speed);

        void onFail(String error);
    }