一、目标
本章实现视频下载的功能
使用说明：进入在线视频，点击播放时将弹出选择框询问播放还是下载，点击下载后进度条将在本地视频顶部显示。如果想边看便下载，请直接点击本地播放列表中正在下载的视频。 二、实现（部分主要实现代码）
FileDownloadHelper
public
class FileDownloadHelper {
private
static
final String TAG = "FileDownloadHelper";
/**
线程池
*/
private ThreadPool mPool =
new ThreadPool();
/**
开始下载
*/
public
static
final
int MESSAGE_START = 0;
/**
更新进度
*/
public
static
final
int MESSAGE_PROGRESS = 1;
/**
下载结束
*/
public
static
final
int MESSAGE_STOP = 2;
/**
下载出错
*/
public
static
final
int MESSAGE_ERROR = 3;
/**
中途终止
*/
private
volatile
boolean mIsStop =
false;
private Handler mHandler;
public
volatile HashMap<String, String> mDownloadUrls =
new HashMap<String, String>();
public FileDownloadHelper(Handler handler) {
if (handler ==
null)
throw
new IllegalArgumentException("handler不能为空!");
this.mHandler = handler;
}
public
void stopALl() {
mIsStop =
true;
mPool.stop();
}
public
void newDownloadFile(
final String url) {
newDownloadFile(url, Environment.getExternalStorageDirectory() + "/" + FileUtils.getUrlFileName(url));
}
/**
* 下载一个新的文件
*
*
@param
url
*
@param
savePath
*/
public
void newDownloadFile(
final String url,
final String savePath) {
if (mDownloadUrls.containsKey(url))
return;
else
mDownloadUrls.put(url, savePath);
mPool.start(
new Runnable() {
@Override
public
void run() {
mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_START, url));
HttpClient client =
new DefaultHttpClient();
HttpGet get =
new HttpGet(url);
InputStream inputStream =
null;
FileOutputStream outputStream =
null;
try {
HttpResponse response = client.execute(get);
HttpEntity entity = response.getEntity();
final
int size = (
int) entity.getContentLength();
inputStream = entity.getContent();
if (size > 0 && inputStream !=
null) {
outputStream =
new FileOutputStream(savePath);
int ch = -1;
byte[] buf =
new
byte[1024];
//
每秒更新一次进度
new Timer().schedule(
new TimerTask() {
@Override
public
void run() {
try {
FileInputStream fis =
new FileInputStream(
new File(savePath));
int downloadedSize = fis.available();
if (downloadedSize >= size)
cancel();
mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_PROGRESS, downloadedSize, size, url));
}
catch (Exception e) {
}
}
}, 50, 1000);
while ((ch = inputStream.read(buf)) != -1 && !mIsStop) {
outputStream.write(buf, 0, ch);
}
outputStream.flush();
}
}
catch (Exception e) {
Log.e(TAG, e.getMessage(), e);
mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_ERROR, url + ":" + e.getMessage()));
}
finally {
try {
if (outputStream !=
null)
outputStream.close();
}
catch (IOException ex) {
}
try {
if (inputStream !=
null)
inputStream.close();
}
catch (IOException ex) {
}
}
mDownloadUrls.remove(url);
mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_STOP, url));
}
});
}
代码说明：
a. ThreadPool是线程池，请参照项目代码。
b. 这里使用了Time定时来刷进度，而没有直接在write数据时更新进度，这样的原因时每秒write较高，更新UI过于频繁，可能导致超时等问题。
Handle
public Handler mDownloadHandler =
new Handler() {
@Override
public
void handleMessage(Message msg) {
PFile p;
String url = msg.obj.toString();
switch (msg.what) {
case FileDownloadHelper.MESSAGE_START:
//
开始下载
p =
new PFile();
p.path = mParent.mFileDownload.mDownloadUrls.get(url);
p.title =
new File(p.path).getName();
p.status = 0;
p.file_size = 0;
if (mDownloadAdapter ==
null) {
mDownloadAdapter =
new FileAdapter(getActivity(),
new ArrayList<PFile>());
mDownloadAdapter.add(p, url);
mTempListView.setAdapter(mDownloadAdapter);
mTempListView.setVisibility(View.VISIBLE);
}
else {
mDownloadAdapter.add(p, url);
mDownloadAdapter.notifyDataSetChanged();
}
break;
case FileDownloadHelper.MESSAGE_PROGRESS:
//
正在下载
p = mDownloadAdapter.getItem(url);
p.temp_file_size = msg.arg1;
p.file_size = msg.arg2;
int status = (
int) ((msg.arg1 * 1.0 / msg.arg2) * 10);
if (status > 10)
status = 10;
p.status = status;
mDownloadAdapter.notifyDataSetChanged();
break;
case FileDownloadHelper.MESSAGE_STOP:
//
下载结束
p = mDownloadAdapter.getItem(url);
FileBusiness.insertFile(getActivity(), p);
break;
case FileDownloadHelper.MESSAGE_ERROR:
Toast.makeText(getActivity(), url, Toast.LENGTH_LONG).show();
break;
}
super.handleMessage(msg);
}
代码说明：
a. mTempListView是新增的，默认是隐藏，请参见项目代码layout部分。
b. 下载流程：开始(显示mTempListView) -> 正在下载(更新进度图片和大小) -> 完成（入裤）
Dialog
if (FileUtils.isVideoOrAudio(url)) {
Dialog dialog =
new AlertDialog.Builder(getActivity()).setIcon(android.R.drawable.btn_star).setTitle("播放/下载").setMessage(url).setPositiveButton("播放",
new OnClickListener() {
@Override
public
void onClick(DialogInterface dialog,
int which) {
Intent intent =
new Intent(getActivity(), VideoPlayerActivity.
class);
intent.putExtra("path", url);
startActivity(intent);
}
}).setNeutralButton("下载",
new OnClickListener() {
@Override
public
void onClick(DialogInterface dialog,
int which) {
MainFragmentActivity activity = (MainFragmentActivity) getActivity();
activity.mFileDownload.newDownloadFile(url);
Toast.makeText(getActivity(), "正在下载 .." + FileUtils.getUrlFileName(url) + " ，可从本地视频查看进度！", Toast.LENGTH_LONG).show();
}
}).setNegativeButton("取消",
null).create();
dialog.show();
return
true;
三、下载
至本章节往后，代码均不再提供下载，请移步
Google Code：
http://code.google.com/p/android-oplayer
本文转自博客园农民伯伯的博客，原文链接：使用Vitamio打造自己的Android万能播放器（7）——在线播放（下载视频），如需转载请自行联系原博主。
