关于使用HttpURLConnection下载大文件的一些问题（UI卡顿） 求大神指导

Question

下面是我的函数
private void getFile() {
new Thread(new Runnable() {
@Override
public void run() {
synchronized (this) {
URL url = null;
InputStream inputStream = null;
FileOutputStream outputStream = null;
long fileSize = 0;
try {
url = new URL(downloadUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(28000);
connection.setRequestMethod("GET");
if (connection.getResponseCode() == 200) {
inputStream = connection.getInputStream();
File file = new File(Environment.getExternalStorageDirectory() + "/" + directoriy, filename);
outputStream = new FileOutputStream(file);
fileSize = connection.getContentLength();
int length = 0;
byte[] buffer = new byte[1024];
int downloadSize = 0;
while ((length = inputStream.read(buffer)) != -1) {
downloadSize = downloadSize + length;
progress[0] = downloadSize / (float) fileSize;
outputStream.write(buffer, 0, length);
handler.sendEmptyMessage(INVALIDATE1);
}
outputStream.flush();
outputStream.close();
handler.sendEmptyMessage(LOAD_SUCCESS1);
}
} catch (MalformedURLException e) {
handler.sendEmptyMessage(LOAD_ERROR1);
e.printStackTrace();
e.getMessage();
try {
if (inputStream != null)
inputStream.close();
if (outputStream != null)
outputStream.close();
} catch (IOException e1) {
e1.printStackTrace();
}
} catch (IOException e) {
handler.sendEmptyMessage(LOAD_ERROR1);
e.printStackTrace();
if (inputStream != null)
try {
inputStream.close();
} catch (IOException e1) {
e1.printStackTrace();
}
if (outputStream != null)
try {
outputStream.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
}).start();

}

用上面的函数下载一个1个G的文件要改成POST方式吗？需要的话函数需要拿些改动呢，还有就是下载启动大文件之后对UI有很大的影响，列表直接卡住了，想请问用什么方法可以优化一下呢？

Answer 1

你已经在线程中下载文件了，不会直接影响UI，一个可能就是你的数据太多，然后更新UI列表的时候导致处理负荷太重。可以降低列表刷新等。