我正在尝试在手机的内部存储中创建一个单独的文件夹，以供应用下载文件。但是该文件夹未在手机中创建。是什么原因？另外，我的应用程序中还有另一个问题，就是当我单击下载按钮时，无法下载照片。
这是下载功能
public void download() {
for (MediaModel item : Items) {
if (item.isSelected) {
Log.d("check", "download");
final String url = item.getFullDownloadURL();
BaseDownloadTask task = FileDownloader.getImpl().create(url);
task.setListener(mFileDownloadListener)
.setPath(Environment.getDataDirectory() + "/" + Constants.STORED_FOLDER, true)
.setAutoRetryTimes(1)
.setCallbackProgressTimes(0)
.asInQueueTask()
.enqueue();
if (FileDownloader.getImpl().start(mFileDownloadListener, true)) {
item.setTaskId(task.getId());
item.setStatus(ItemStatus.DOWNLOADING);
Logging.e(TAG, "start download task: " + task.getId());
} else {
item.setTaskId(task.getId());
item.setStatus(ItemStatus.NORMAL);
Logging.e(TAG, "error download task: " + task.getId());
}
}
}
}
答案 0 :(得分：0)
用于创建文件夹
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Your Folder Name";
File folder = new File(path);
if (!folder.exists()) {
folder.mkdir();
}
另请参阅以下答案：https://stackoverflow.com/a/35471045/9060917
更新
public void download() {
for (MediaModel item : Items) {
if (item.isSelected) {
File file = new File(getFilesDir(),"Your directory name");
if(!file.exists()){
file.mkdir();
}
try{
Log.d("check", "download");
final String url = item.getFullDownloadURL();
BaseDownloadTask task = FileDownloader.getImpl().create(url);
task.setListener(mFileDownloadListener)
.setPath(file.getAbsolutePath(), true)
.setAutoRetryTimes(1)
.setCallbackProgressTimes(0)
.asInQueueTask()
.enqueue();
}catch (Exception e){
e.printStackTrace();
}
if (FileDownloader.getImpl().start(mFileDownloadListener, true)) {
item.setTaskId(task.getId());
item.setStatus(ItemStatus.DOWNLOADING);
Logging.e(TAG, "start download task: " + task.getId());
} else {
item.setTaskId(task.getId());
item.setStatus(ItemStatus.NORMAL);
Logging.e(TAG, "error download task: " + task.getId());
}
}
}
}
我希望您在清单中添加这些权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
更新
将文件保存到内部存储器时，可以通过调用方法获取适当的目录作为文件
getFilesDir（）
File directory = context.getFilesDir();
File file = new File(directory, filename);
或者，您可以调用openFileOutput（）来获取FileOutputStream，该文件将写入内部目录中的文件。例如，以下是将一些文本写入文件的方法：
String filename = "myfile";
String fileContents = "Hello world!";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
outputStream.write(fileContents.getBytes());
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
更多参考
https://developer.android.com/training/data-storage/files#java
答案 1 :(得分：0)
尝试此代码：
private class DownloadingTask extends AsyncTask<Void, Void, Void> {
File apkStorage = null;
File outputFile = null;
@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog=new ProgressDialog(context);
progressDialog.setMessage("Downloading...");
progressDialog.show();
}
@Override
protected void onPostExecute(Void result) {
try {
if (outputFile != null) {
progressDialog.dismiss();
CDToast.makeText(context, context.getResources().getString(R.string.downloaded_successfully), CDToast.LENGTH_SHORT, CDToast.TYPE_SUCCESS).show();
Notification();
vibrateDevice(100);
} else {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
}
}, 3000);
CDToast.makeText(context, context.getResources().getString(R.string.download_failed), CDToast.LENGTH_SHORT, CDToast.TYPE_ERROR).show();
}
} catch (Exception e) {
e.printStackTrace();
//Change button text if an exception occurs
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
}
}, 3000);
Log.e(TAG, "Download Failed with Exception - " + e.getLocalizedMessage());
}
super.onPostExecute(result);
}
@Override
protected Void doInBackground(Void... arg0) {
try {
URL url = new URL(downloadUrl);//Create Download URl
HttpURLConnection c = (HttpURLConnection) url.openConnection();//Open Url Connection
c.setRequestMethod("GET");//Set Request Method to "GET" since we are grtting data
c.connect();//connect the URL Connection
//If Connection response is not OK then show Logs
if (c.getResponseCode() != HttpURLConnection.HTTP_OK) {
Log.e(TAG, "Server returned HTTP " + c.getResponseCode()
+ " " + c.getResponseMessage());
}
//Get File if SD card is present
if (new CheckForSDCard().isSDCardPresent()) {
apkStorage = new File(
Environment.getExternalStorageDirectory() + "/"
+ "New_Folder_Name_Here");
} else
Toast.makeText(context, "Oops!! There is no SD Card.", Toast.LENGTH_SHORT).show();
//If File is not present create directory
if (!apkStorage.exists()) {
apkStorage.mkdir();
Log.e(TAG, "Directory Created.");
}
outputFile = new File(apkStorage, downloadFileName);//Create Output file in Main File
//Create New File if not present
if (!outputFile.exists()) {
outputFile.createNewFile();
Log.e(TAG, "File Created");
}
FileOutputStream fos = new FileOutputStream(outputFile);//Get OutputStream for NewFile Location
InputStream is = c.getInputStream();//Get InputStream for connection
byte[] buffer = new byte[1024];//Set buffer type
int len1 = 0;//init length
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);//Write new file
}
//Close all connection after doing task
fos.close();
is.close();
} catch (Exception e) {
//Read exception if something went wrong
e.printStackTrace();
outputFile = null;
Log.e(TAG, "Download Error Exception " + e.getMessage());
}
return null;
}
}
用于检查 SD卡：
public class CheckForSDCard {
//Check If SD Card is present or not method
public boolean isSDCardPresent() {
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
return true;
}
return false;
}
}
答案 2 :(得分：0)
在Android Studio中使用内部存储首先在清单中添加权限 像这样：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
然后使用以下代码行在内部存储中创建新目录：
File sdCardRoot = new File(Environment.getExternalStorageDirectory(), "MyProfile");
if (!sdCardRoot.exists()) {
sdCardRoot.mkdirs();
}
Log.e("check_path", "" + sdCardRoot.getAbsolutePath());
这是我的完整代码：
在此代码中检查目录是否存在，如果目录不存在，则创建目录 并使用asyntask从url下载图像
在此示例中，我使用了Java语言
代码
MyAsyncTasks asyncTasks = new MyAsyncTasks();
asyncTasks.execute(Imageurl);
和AsyncClass：
class MyAsyncTasks extends AsyncTask<String, String, String> {
File sdCardRoot;
@Override
protected String doInBackground(String... strings) {
HttpURLConnection urlConnection = null;
try {
URL url = new URL(strings[0]);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.connect();
sdCardRoot = new File(Environment.getExternalStorageDirectory(), "MyProfile");
if (!sdCardRoot.exists()) {
sdCardRoot.mkdirs();
}
Log.e("check_path", "" + sdCardRoot.getAbsolutePath());
String fileName =
strings[0].substring(strings[0].lastIndexOf('/') + 1, strings[0].length());
Log.e("dfsdsjhgdjh", "" + fileName);
File imgFile =
new File(sdCardRoot, fileName);
if (!sdCardRoot.exists()) {
imgFile.createNewFile();
}
InputStream inputStream = urlConnection.getInputStream();
int totalSize = urlConnection.getContentLength();
FileOutputStream outPut = new FileOutputStream(imgFile);
int downloadedSize = 0;
byte[] buffer = new byte[2024];
int bufferLength = 0;
while ((bufferLength = inputStream.read(buffer)) > 0) {
outPut.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
Log.e("Progress:", "downloadedSize:" + Math.abs(downloadedSize * 100 / totalSize));
}
Log.e("Progress:", "imgFile.getAbsolutePath():" + imgFile.getAbsolutePath());
Log.e(TAG, "check image path 2" + imgFile.getAbsolutePath());
mImageArray.add(imgFile.getAbsolutePath());
outPut.close();
} catch (IOException e) {
e.printStackTrace();
Log.e("checkException:-", "" + e);
}
return null;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
imagecount++;
Log.e("check_count", "" + totalimagecount + "==" + imagecount);
if (totalimagecount == imagecount) {
pDialog.dismiss();
imagecount = 0;
}
Log.e("ffgnjkhjdh", "checkvalue checkvalue" + checkvalue);
}
}
答案 3 :(得分：0)
通过此方法传递要下载的图像的URL。
/*--Download Image in Storage--*/
public void downloadImage(String URL) {
final Long reference;
downloadManager = (DownloadManager) getActivity().getSystemService(Context.DOWNLOAD_SERVICE);
Uri uri = Uri.parse(URL);
DownloadManager.Request request = new DownloadManager.Request(uri);
request.setTitle("AppName");
request.setDestinationInExternalPublicDir(String.format("%s/%s", Environment.getExternalStorageDirectory(),
getString(R.string.app_name)), "FileName.jpg");
Log.i("myi", "downloadImage: " + request.setDestinationInExternalPublicDir(String.format("%s/%s", Environment.getExternalStorageDirectory(),
getString(R.string.app_name)), "FileName.jpg"));
request.setVisibleInDownloadsUi(true);
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
reference = downloadManager.enqueue(request);
Log.d("download", "Image Download : " + reference);
BroadcastReceiver onComplete = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
try {
Toast.makeText(this, "Image Downloaded Successfully ", Toast.LENGTH_LONG);
} catch (Exception e) {
}
}
};
getApplicationContext().registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
}
答案 4 :(得分：0)
向 AndroidManifest.xml 文件添加所需的权限。
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
为应用程序添加 requestLegacyExternalStorage。
<application
android:requestLegacyExternalStorage="true">
</application>
将以下代码段添加到 MainActivity.java
File f = new File(Environment.getExternalStorageDirectory(), "My folder");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
try {
Files.createDirectory(Paths.get(f.getAbsolutePath()));
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), e.getLocalizedMessage(), Toast.LENGTH_LONG).show();
}
} else {
f.mkdir();
f.mkdirs();
Toast.makeText(getApplicationContext(), f.getPath(), Toast.LENGTH_LONG).show();
}
现在，触发下载的代码类似于：
String url="Here download Url paste";
DownloadManager downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url.toString()));
request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_MOBILE | DownloadManager.Request.NETWORK_WIFI);
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.allowScanningByMediaScanner();
request.setDestinationInExternalPublicDir("/My folder", fileName);
downloadManager.enqueue(request);