/**
* 开始下载文件
*
* @param listener 监听下载数量的变化,如果不需要了解实时下载的数量,可以设置为null
* @return 已下载文件大小
* @throws Exception
*/
public int download(DownloadProgressListener listener) throws Exception {
try {
RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");
if (this.fileSize > 0) randOut.setLength(this.fileSize);
randOut.close();
URL url = new URL(this.downloadUrl);
if (this.data.size() != this.threads.length) {
this.data.clear();
for (int i = 0; i < this.threads.length; i++) {
this.data.put(i + 1, 0); // 初始化每条线程已经下载的数据长度为0
}
}
for (int i = 0; i < this.threads.length; i++) { // 开启线程进行下载
int downLength = this.data.get(i + 1);
if (downLength < this.block && this.downloadSize < this.fileSize) { // 判断线程是否已经完成下载,否则继续下载
this.threads[i] =
new DownloadThread(this, url, this.saveFile, this.block, this.data.get(i + 1), i + 1);
this.threads[i].setPriority(7);
this.threads[i].start();
} else {
this.threads[i] = null;
}
}
this.fileService.save(this.downloadUrl, this.data);
boolean notFinish = true; // 下载未完成
while (notFinish) { // 循环判断所有线程是否完成下载
Thread.sleep(900);
notFinish = false; // 假定全部线程下载完成
for (int i = 0; i < this.threads.length; i++) {
if (this.threads[i] != null && !this.threads[i].isFinish()) { // 如果发现线程未完成下载
notFinish = true; // 设置标志为下载没有完成
if (this.threads[i].getDownLength() == -1) { // 如果下载失败,再重新下载
this.threads[i] =
new DownloadThread(
this, url, this.saveFile, this.block, this.data.get(i + 1), i + 1);
this.threads[i].setPriority(7);
this.threads[i].start();
}
}
}
if (listener != null) listener.onDownloadSize(this.downloadSize); // 通知目前已经下载完成的数据长度
}
fileService.delete(this.downloadUrl);
} catch (Exception e) {
print(e.toString());
throw new Exception("file download fail");
}
return this.downloadSize;
}
@Override
public void deleteGeneratedImages(URI uri) throws Exception {
for (ImageStyle imageStyle : imageStyles.values()) {
fileService.delete(buildGeneratedImagePath(imageStyle, uri));
}
}