这是我的代码，downloadFile(String URLS)正在下载功能。
我使用istagram API下载流行的图像，但只下载了一个图像，其余的图像没有被下载。
如何从服务器下载图像？
我知道downloadFile(String URLS)函数存在问题，但我无法解决此问题。
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mInstagram = new Instagram(this, CLIENT_ID, CLIENT_SECRET, REDIRECT_URI);
mInstagramSession = mInstagram.getSession();
if (mInstagramSession.isActive()) {
setContentView(R.layout.activity_user);
InstagramUser instagramUser = mInstagramSession.getUser();
mLoadingPb = (ProgressBar) findViewById(R.id.pb_loading);
mGridView = (GridView) findViewById(R.id.gridview);
((TextView) findViewById(R.id.tv_name)).setText(instagramUser.fullName);
((TextView) findViewById(R.id.tv_username)).setText(instagramUser.username);
((Button) findViewById(R.id.btn_logout)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
mInstagramSession.reset();
startActivity(new Intent(MainActivity.this, MainActivity.class));
finish();
}
});
((Button) findViewById(R.id.btn_slideshow))
.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent i = new Intent(MainActivity.this,
SlideshowActivity.class);
startActivity(i);
finish();
}
});
ImageView userIv = (ImageView) findViewById(R.id.iv_user);
DisplayImageOptions displayOptions = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_user)
.showImageForEmptyUri(R.drawable.ic_user)
.showImageOnFail(R.drawable.ic_user)
.cacheInMemory(true)
.cacheOnDisc(false)
.considerExifParams(true)
.build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(this)
.writeDebugLogs()
.defaultDisplayImageOptions(displayOptions)
.build();
ImageLoader imageLoader = ImageLoader.getInstance();
imageLoader.init(config);
AnimateFirstDisplayListener animate = new AnimateFirstDisplayListener();
imageLoader.displayImage(instagramUser.profilPicture, userIv, animate);
imageLoader.destroy();
new DownloadTask().execute();
} else {
setContentView(R.layout.activity_main);
((Button) findViewById(R.id.btn_connect)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
mInstagram.authorize(mAuthListener);
}
});
}
}
private void showToast(String text) {
Toast.makeText(getApplicationContext(), text, Toast.LENGTH_LONG).show();
}
private Instagram.InstagramAuthListener mAuthListener = new Instagram.InstagramAuthListener() {
@Override
public void onSuccess(InstagramUser user) {
finish();
startActivity(new Intent(MainActivity.this, MainActivity.class));
}
@Override
public void onError(String error) {
showToast(error);
}
@Override
public void onCancel() {
showToast("OK. Maybe later?");
}
};
public static class AnimateFirstDisplayListener extends SimpleImageLoadingListener {
static final List<String> displayedImages = Collections.synchronizedList(new LinkedList<String>());
@Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
if (loadedImage != null) {
ImageView imageView = (ImageView) view;
boolean firstDisplay = !displayedImages.contains(imageUri);
if (firstDisplay) {
FadeInBitmapDisplayer.animate(imageView, 500);
displayedImages.add(imageUri);
}
}
}
}
public class DownloadTask extends AsyncTask<URL, Integer, Long> {
ArrayList<String> photoList;
protected void onCancelled() {
}
protected void onPreExecute() {
}
protected Long doInBackground(URL... urls) {
long result = 0;
try {
params = new ArrayList<NameValuePair>(1);
params.add(new BasicNameValuePair("count", "10"));
System.out.println("PARAMS==="+params);
InstagramRequest request = new InstagramRequest(mInstagramSession.getAccessToken());
response= request.createRequest("GET", "/media/popular", params);
System.out.println("RESPONCE VALUE ==="+response);
rootPath = Environment.getExternalStorageDirectory().toString()+File.separator+"InstagramFavourites";
rootFileDirectory= new File (rootPath);
rootFileDirectory.mkdir();
Log.w("TAG", "Folder Created: " + rootPath);
System.out.println("IMAGES DOWNLOADED IN FOLDER=="+rootFileDirectory);
if (!response.equals("")) {
JSONObject jsonObj = (JSONObject) new JSONTokener(response).nextValue();
JSONArray jsonData = jsonObj.getJSONArray("data");
int length = jsonData.length();
if (length > 0) {
photoList = new ArrayList<String>();
for (int i = 0; i < length; i++) {
JSONObject jsonPhoto = jsonData.getJSONObject(i).getJSONObject("images").getJSONObject("low_resolution");
photoList.add(jsonPhoto.getString("url"));
downloadFile(jsonPhoto.getString("url"));
//downloadFile(jsonObj.toString());
//downloadFile(photoList.get(i));
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
protected void onProgressUpdate(Integer... progress) {
}
protected void onPostExecute(Long result) {
mLoadingPb.setVisibility(View.GONE);
if (photoList == null) {
Toast.makeText(getApplicationContext(), "No Photos Available", Toast.LENGTH_LONG).show();
} else {
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = (int) Math.ceil((double) dm.widthPixels / 2);
width=width-50;
int height = width;
PhotoListAdapter adapter = new PhotoListAdapter(MainActivity.this);
adapter.setData(photoList);
adapter.setLayoutParam(width, height);
mGridView.setAdapter(adapter);
}
}
void downloadFile(String URLS){
count=count++;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(URLS.toString());
System.out.println("URL VALUES"+url);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//connect
urlConnection.connect();
String fileName=rootPath+File.separator+"abc"+ count+".png" ;
File fs=new File(fileName);
fs.createNewFile();
FileOutputStream fileOutput = new FileOutputStream(fs);
int status = urlConnection.getResponseCode();
InputStream inputStream;
if(status >= HttpStatus.SC_BAD_REQUEST)
{
inputStream = urlConnection.getErrorStream();
System.out.println("ERROR");
}
else
inputStream = urlConnection.getInputStream();
//Stream used for reading the data from the internet
// inputStream = urlConnection.getInputStream();
//this is the total size of the file which we are downloading
totalsize = urlConnection.getContentLength();
runOnUiThread(new Runnable() {
public void run() {
// pb.setMax(totalsize);
}
});
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
fileOutput.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
// update the progressbar //
runOnUiThread(new Runnable() {
public void run() {
// pb.setProgress(downloadedSize);
// float per = ((float)downloadedSize/totalsize) * 100;
// System.out.println("Float per value=="+per);
//cur_val.setText("Downloaded " + downloadedSize + "KB / " + totalSize + "KB (" + (int)per + "%)" );
}
});
}
//close the output stream when complete //
fileOutput.close();
runOnUiThread(new Runnable() {
public void run() {
// pb.dismiss(); // if you want close it..
}
});
} catch (final MalformedURLException e) {
showError("Error : MalformedURLException " + e);
e.printStackTrace();
} catch (final IOException e) {
showError("Error : IOException " + e);
e.printStackTrace();
}
catch (final Exception e) {
showError("Error : Please check your internet connection " + e);
}
finally
{
urlConnection.disconnect();
}
}
void showError(final String err){
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(getApplicationContext(), err, Toast.LENGTH_LONG).show();
}
});
}
}
}
enter code here
答案 0 :(得分：1)
我建议您使用：Picasso这是一个很棒的图书馆，可以安装在Android上。
答案 1 :(得分：0)
而不是使用AsyncTask，你可以像Universal-Image-Loader那样使用任何Image Loader。在循环中
for(...)
{
Bitmap bmp = imageLoader.loadImageSync(imageUri);
// save bitmap here.
}
或者您可以像here一样使用下载管理器。 你可以在循环中做同样的多个图像下载。
答案 2 :(得分：0)
我建议使用Universal Image Loader，它快速，易于使用并且可以处理大部分内容。
答案 3 :(得分：0)
我的回答很晚，但是迟到总比没有好！＆＃34;
使用ThreadPoolExecutor下载多个文件的教程对我有很大帮助：Downloading Multiple Files In Android Using ThreadPoolExecutor