/**
* 开始下载文件 <b>方法描述：</b> <br>
*
* @param listner
* @return
* @exception <br>
* @since 1.0.0
*/
public int download(DownloadProgressListner listner) {
try {
RandomAccessFile accessFile = new RandomAccessFile(saveFile, "rw");
if (fileSize > 0) {
accessFile.setLength(fileSize);
}
accessFile.close();
URL url = new URL(downloadurl);
if (data.size() != threads.length) { // 如果原先下载的线程数和现在下载的线程数不一致
this.data.clear(); // 对原来的map集合清空
for (int i = 0; i < threads.length; i++) {
data.put(i + 1, 0); // 初始化每天线程已经下载的数据长度为0
}
downloadSize = 0;
}
for (int i = 0; i < threads.length; i++) { // 开启线程进行下载
int downloadlength = this.data.get(i + 1); // 给当前的第i个线程赋下载长度。
if (downloadlength < block && downloadSize < fileSize) { // 判断线程是否已完成下载，负责继续下载
this.threads[i] =
new DownloadThread(
this, block, saveFile, i + 1, url, this.data.get(i + 1)); // 线程Id从1开始
this.threads[i].setPriority(7);
this.threads[i].start();
} else {
this.threads[i] = null;
}
}
fileService.delete(downloadurl);
fileService.save(downloadurl, data);
boolean notFinish = true; // 下载未完成。
while (notFinish) {
Thread.sleep(900);
for (int i = 0; i < threads.length; i++) {
if (this.threads[i] != null && !this.threads[i].isfinish()) {
notFinish = true;
if (threads[i].getDownloadLength() == -1) { // 如果下载失败，再重新下载。
this.threads[i] =
new DownloadThread(this, block, saveFile, i + 1, url, this.data.get(i + 1));
this.threads[i].setPriority(7);
this.threads[i].start();
}
}
}
if (listner != null) {
listner.onDownloadSize(downloadSize);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return downloadSize;
}
/**
* <b>方法描述：</b> <br>
*
* @param args
* @exception <br>
* @since 1.0.0
*/
public FileDownLoader(Context context, String downloadurl, File savedirFile, int thredNum) {
try {
this.downloadurl = downloadurl;
URL url = new URL(downloadurl);
threads = new DownloadThread[thredNum];
this.context = context;
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(5000);
connection.setRequestMethod("GET");
connection.setRequestProperty(
"Accept",
"image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
connection.setRequestProperty("Accept-Language", "zh-CN");
connection.setRequestProperty("Charset", "UTF-8");
connection.setRequestProperty(
"User-Agent",
"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
connection.setRequestProperty("Connection", "Keep-Alive");
connection.connect();
if (connection.getResponseCode() == 200) {
fileSize = connection.getContentLength();
block =
(fileSize % threads.length) == 0
? fileSize / threads.length
: fileSize / threads.length + 1; // 计算每条线程下载的数据长度
String fileName = downloadurl.substring(downloadurl.lastIndexOf("/") + 1); // 获得文件名
this.saveFile = new File(savedirFile, fileName);
fileService = new FileService(context);
Map<Integer, Integer> logdata = fileService.getData(downloadurl);
if (logdata.size() > 0) { // 如果存在下载记录
for (Map.Entry<Integer, Integer> entry : logdata.entrySet()) {
data.put(entry.getKey(), entry.getValue()); // 把各条线程已经下载的数据长度放入data中。
}
}
if (data.size() == threads.length) { // 计算所有线程已经下载的数据总长度
for (int i = 0; i < threads.length; i++) {
downloadSize += data.get(i + 1);
}
Log.i("downloadService", "已经下载的数据长度" + downloadSize);
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 更新指定线程最后下载的位置 方法前要加上synchronized <b>方法描述：</b> <br>
*
* @param threadId
* @param downlength
* @exception <br>
* @since 1.0.0
*/
public synchronized void update(int threadId, int downlength) {
this.data.put(threadId, downlength);
fileService.update(this.downloadurl, threadId, downlength);
}