Android实现多线程下载文件的方法

downloadinfo.setText("当前进度:" + progress + "%"); }

downloadProgressBar.setProgress(progress); }

}; public class downloadTask extends Thread {

private int blockSize, downloadSizeMore; private int threadNum = 5;

String urlStr, threadNo, fileName; public downloadTask(String urlStr, int threadNum, String fileName) {

this.urlStr = urlStr; this.threadNum = threadNum;

this.fileName = fileName; }

@Override public void run() {

FileDownloadThread[] fds = new FileDownloadThread[threadNum]; try {

URL url = new URL(urlStr); URLConnection conn = url.openConnection();

//防止返回-1 InputStream in = conn.getInputStream();

//获取下载文件的总大小 fileSize = conn.getContentLength();

Log.i("bb", "======================fileSize:"+fileSize); //计算每个线程要下载的数据量

blockSize = fileSize / threadNum; // 解决整除后百分比计算误差

downloadSizeMore = (fileSize % threadNum); File file = new File(fileName);

for (int i = 0; i < threadNum; i++) { Log.i("bb", "======================i:"+i);

//启动线程，分别下载自己需要下载的部分 FileDownloadThread fdt = new FileDownloadThread(url, file, i * blockSize, (i + 1) * blockSize - 1);

fdt.setName("Thread" + i); fdt.start();

fds[i] = fdt; }

boolean finished = false; while (!finished) {

// 先把整除的余数搞定 downloadedSize = downloadSizeMore;

finished = true; for (int i = 0; i < fds.length; i++) {