android 下载功能代码问题！
为什么真机测试时会下载到某个百分比就卡住？？请教CountDownLatch 用法？请教RandomAccessFile用法？可以运用下载到手机内存中吗？？ 请教如何让UI界面流畅？因为我开始下载后UI界面很卡。 再请教如何让易做图提高问题？？麻烦高手指点！！解决一个问题是一个谢谢咯！！！
private CountDownLatch latch = new CountDownLatch(THREAD_COUNT);
。。。。
try {
URL url = new URL(downloadUrl);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setConnectTimeout(5 * 1000);
conn.setRequestMethod("GET");
if (conn.getResponseCode() == 200) {
fileSize = conn.getContentLength();
if (fileSize <= 0)
throw new RuntimeException("Unkown file size ");
if (!Utility.isEnoughForDownload(fileSize)) {
download();
} else {
saveFile = new File(fileSaveDir, downloadFileName);// 构建保存文件
long packageLength = fileSize / THREAD_COUNT;// 每个线程要下载的字节数
long leftLength = fileSize % THREAD_COUNT;// 剩下的字节数
RandomAccessFile randomAccessFile = new RandomAccessFile(
saveFile, "rw");
count = 0;
long pos = 0;
for (int i = 0; i < THREAD_COUNT; i++) {
long endPos = pos + packageLength;
new DownloadThread(url, randomAccessFile, pos, endPos)
.start();
if (leftLength > 0) {
endPos++;
leftLength--;
}
pos = endPos;
}
finished = true;
latch.await();
// }else{
// download();
// }
// long t8=System.currentTimeMillis();
// Log.i("timeTest","newfile "+String.valueOf(t8-t5));
}
} else {
throw new RuntimeException("server no response ");
}
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (ProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
// } catch (InterruptedException e) {
// TODO Auto-generated catch block
// e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
。。。
class DownloadThread extends Thread {
private URL url;
private RandomAccessFile file;
private long from;
private long end;
/**
* @param url
* 下载的URL
* @param file
* 下载完成之后存储的文件
* @param from
* 当前线程对应文件的起始位置
* @param end
* 当前线程对应文件的结束位置
*/
DownloadThread(URL url, RandomAccessFile file, long from, long end) {
this.url = url;
this.file = file;
this.from = from;
this.end = end;
}
public void run() {
try {
long pos = from;
byte[] buf = new byte[1024000];
HttpURLConnection cn = (HttpURLConnection) url.openConnection();
cn.setRequestProperty("Range", "bytes=" + from + "-" + end);
InputStream is = cn.getInputStream();
int len;
while ((len = is.read(buf)) > 0) {
// synchronized (file) {
file.seek(pos);
file.write(buf, 0, len);
// }
pos += len;
count += len;
finishPercent = count * 100 / fileSize;
Log.e(TAG, "run" + Thread.currentThread().getId() + " "
+ String.valueOf(finishPercent));
mHandler.post(mUpdatePercent);
}
cn.disconnect();
} catch (Exception e) {
e.printStackTrace();
Log.e(TAG, e.toString());
}
latch.countDown();
}
} --------------------编程问答-------------------- 说实话,代码看得好累. --------------------编程问答-------------------- 好吧 不论怎样还是谢谢~~
补充：移动开发 , Android
