Develop Reference

How to get into the Downloads Folder to load all the pictures?

I want to add the downloads folder to my code,
this is my helper class (File Paths):
//"storage/emulated/0" = Environment.getExternalStorageDirectory().getPath().
public String ROOT_DIR = Environment.getExternalStorageDirectory().getPath();
public String PICTURES = ROOT_DIR + "/Pictures";
public String CAMERA = ROOT_DIR + "/DCIM/camera";
public String DOWNLOADS = ROOT_DIR + "/Download";
and this my class where I use this paths
private void init(){
FilePaths filePaths = new FilePaths();
//check for other folders indide "/storage/emulated/0/pictures"
if(FileSearch.getDirectoryPaths(filePaths.PICTURES) != null){
directories = FileSearch.getDirectoryPaths(filePaths.PICTURES);
}
ArrayList<String> directoryNames = new ArrayList<>();
for(int i = 0; i < directories.size(); i++){
int index = directories.get(i).lastIndexOf("/");
String string = directories.get(i).substring(index);
directoryNames.add(string);
}
directories.add(filePaths.CAMERA);
directories.add(filePaths.DOWNLOADS);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_spinner_item, directories); // WARUM
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
directorySpinner.setAdapter(adapter);
directorySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Log.d(TAG, "onItemClick: selected: " + directories.get(position));
//setup image grid for the directory chosen
setupGridView(directories.get(position));
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
If I cut the downloads part out, I get all the files of the other paths but if the downloads part is inside my code, I got an Exception because the downloads files arent added to the arrayList later.
I need the correct path for the downloads.
I found this:
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
but this returns me a file and I need a String in my helper class.
EDIT:
Sorry, it was my fault. I got the Exception because I didnt had any pictures in my other directories. After I inserted one, my Downloads Folder was showed. I solved this error with try and catch now.

You can get String path from File like this
String path = file.toURI().toString();

Unable to pick file on Oreo

On Android Nougat and below, I can simply get some file on my storage using this code :
Intent chooseFile = new Intent(Intent.ACTION_GET_CONTENT);
chooseFile.setType("*/*.jpg");
chooseFile = Intent.createChooser(chooseFile, "Choose a file");
startActivityForResult(chooseFile, 111);
And get the file path using :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 111 && resultCode == RESULT_OK && data.getData() != null)
String path = data.getData().getPath();
}
But on Android Oreo, this is not working. The file picker is showing up, but I cannot even pick the file using the default file picker. At first, I thought that this is related to permission. But after I add the permission to READ and WRITE external storage on runtime, and granted, this problem still occurred.

Since the default file picker on OREO is troublesome, currently I'm using a custom class to pick file or directory. Another solution is you can use ES File Explorer, etc, but not all of your user has it and the main problem still occurred.
public class FileChooser {
private Activity activity;
private Item[] fileList;
private File path;
private boolean rootDir = true; //check if the current directory is rootDir
private boolean pickFile = true; //flag to get directory or file
private String title = "";
private String upTitle = "Up";
private String positiveTitle = "Choose Path";
private String negativeTitle = "Cancel";
private ListAdapter adapter;
private ArrayList<String> str = new ArrayList<>(); //Stores names of traversed directories, to detect rootDir
private Listener listener;
/**
* #param pickFile true for file picker and false for directory picker
* */
public FileChooser(Activity activity, boolean pickFile, Listener fileChooserListener) {
this.activity = activity;
this.pickFile = pickFile;
this.listener = fileChooserListener;
title = pickFile ? "Choose File" : "Choose Directory";
path = new File(String.valueOf(Environment.getExternalStorageDirectory()));
}
/**
* The view of your file picker
* */
public void openDirectory() {
loadFileList();
AlertDialog.Builder builder = new AlertDialog.Builder(activity, AlertDialog.THEME_DEVICE_DEFAULT_DARK);
if (fileList == null)
builder.create();
builder.setTitle(title + "\n" + path.toString());
builder.setAdapter(adapter, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int position) {
String chosenFile = fileList[position].file;
File selectedFile = new File(path + File.separator + chosenFile);
if (selectedFile.isDirectory()) { // user click on folder
rootDir = false;
str.add(chosenFile); // Adds chosen directory to list
path = selectedFile;
openDirectory();
}
else if (chosenFile.equalsIgnoreCase(upTitle) && !selectedFile.exists()) { // 'up' was clicked
String s = str.remove(str.size() - 1); // present directory
path = new File(
path.toString().substring(0, path.toString().lastIndexOf(s))); // exclude present directory
if (str.isEmpty()) // no more directories in the list, rootDir
rootDir = true;
openDirectory();
}
else if (listener != null && pickFile)
listener.onSelectedPath(selectedFile.getAbsolutePath());
}
});
if (!pickFile) {
builder.setPositiveButton(positiveTitle, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
if (listener != null)
listener.onSelectedPath(path.getPath());
}
});
}
builder.setNegativeButton(negativeTitle, null);
builder.show();
}
/**
* Setup your file picker data
* */
private void loadFileList() {
fileList = null;
if (path.exists()) {
FilenameFilter filter = new FilenameFilter() {
#Override
public boolean accept(File dir, String filename) {
File file = new File(dir, filename);
// Filters based on whether the file is hidden or not
return ((pickFile && file.isFile()) || file.isDirectory()) && !file.isHidden();
}
};
String[] fList = path.list(filter); //set filter
if (fList != null) {
fileList = new Item[fList.length];
for (int i = 0; i < fList.length; i++)
fileList[i] = new Item(fList[i], new File(path, fList[i]).isDirectory() ?
R.drawable.ic_folder : R.drawable.ic_file); //set icon, directory or file
if (!rootDir) {
Item temp[] = new Item[fileList.length + 1];
System.arraycopy(fileList, 0, temp, 1, fileList.length);
temp[0] = new Item(upTitle, R.drawable.ic_undo);
fileList = temp;
}
}
} else
path = new File(String.valueOf(Environment.getExternalStorageDirectory()));
try {
adapter = new ArrayAdapter<Item>(activity,
android.R.layout.select_dialog_item, android.R.id.text1,
fileList) {
#NonNull
#Override
public View getView(int position, View convertView, #NonNull ViewGroup parent) {
// creates view
View view = super.getView(position, convertView, parent);
TextView textView = view.findViewById(android.R.id.text1);
textView.setTextColor(Color.WHITE);
// put the image on the text view
textView.setCompoundDrawablesWithIntrinsicBounds(fileList[position].icon, 0, 0, 0);
// add margin between image and text (support various screen densities)
int dp5 = (int) (5 * activity.getResources().getDisplayMetrics().density + 0.5f);
textView.setCompoundDrawablePadding(dp5);
return view;
}
};
} catch (Exception e) {
e.printStackTrace();
}
}
private class Item {
public String file;
public int icon;
private Item(String file, Integer icon) {
this.file = file;
this.icon = icon;
}
#Override
public String toString() {
return file;
}
}
public interface Listener {
void onSelectedPath(String path);
}
}

How to get the file extension in Android?

I am a newbie.
I have an EditText and a Browse Button to explore Folders and select files only.
From the Browse Button, when a file is clicked it stores the folder path in which that file is in one string and the file name without extension in other string, which I am using to store, either of these two, in the EditText.
I want to make the file name with the exactly file extension (whether one or two dots), but I don't have any idea how to get the file extension also.
All answers will be appreciated.
FileChooser.java
package com.threefriends.filecrypto;
/**
* Created by hp on 01-06-2016.
*/
import java.io.File;
import java.sql.Date;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.text.DateFormat;
import android.os.Bundle;
import android.app.ListActivity;
import android.content.Intent;
import android.view.View;
import android.widget.ListView;
public class FileChooser extends ListActivity {
private File currentDir;
private FileArrayAdapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
currentDir=new File("/sdcard/");
fill(currentDir);
}
private void fill(File f)
{
File[]dirs=f.listFiles();
this.setTitle("Current Dir: "+f.getName());
List<Item>dir=new ArrayList<Item>();
List<Item>fls=new ArrayList<Item>();
try{
for(File ff: dirs)
{
Date lastModDate=new Date(ff.lastModified());
DateFormat formater=DateFormat.getDateTimeInstance();
String date_modify=formater.format(lastModDate);
if(ff.isDirectory()){
File[] fbuf=ff.listFiles();
int buf=0;
if(fbuf != null){
buf=fbuf.length;
}
else
buf=0;
String num_item=String.valueOf(buf);
if(buf == 0)
num_item=num_item+" item";
else
num_item = num_item+" items";
//String formated = lastModDate.toString();
dir.add(new Item(ff.getName(), num_item, date_modify, ff.getAbsolutePath(), "directory_icon"));
}
else
{
fls.add(new Item(ff.getName(), ff.length()+" Byte", date_modify, ff.getAbsolutePath(), "file_icon"));
}
}
}catch(Exception e)
{
}
Collections.sort(dir);
Collections.sort(fls);
dir.addAll(fls);
if(!f.getName().equalsIgnoreCase("sdcard"))
dir.add(0, new Item("..", "Parent Directory", "", f.getParent(), "directory_up"));
adapter=new FileArrayAdapter(FileChooser.this, R.layout.file_view, dir);
this.setListAdapter(adapter);
}
#Override
protected void onListItemClick(ListView l, View v, int position, long id){
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
Item o = adapter.getItem(position);
if(o.getImage().equalsIgnoreCase("directory_icon") || o.getImage().equalsIgnoreCase("directory_up")){
currentDir=new File(o.getPath());
fill(currentDir);
}
else
{
onFileClick(o);
}
}
private void onFileClick(Item o)
{
//Toast.makeText(this, "Folder Clicked: "+ currentDir, Toast.LENGTH_SHORT).show();
Intent intent = new Intent();
intent.putExtra("GetPath", currentDir.toString());
intent.putExtra("GetFileName", o.getName());
setResult(RESULT_OK, intent);
finish();
}
}
Part of MainActivity.java
//Defined for file edittext.
EditText editText2;
private static String TAG = MainFragment.class.getSimpleName(); //For File Exploring.
private static final int REQUEST_PATH = 1;
String curFileName;
String filePath;
EditText edittext;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_main, container, false);
edittext = (EditText) view.findViewById(R.id.editText); //Done for File Exploring, EditText, Browse Button.
Button b1 = (Button) view.findViewById(R.id.skipButton);
b1.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
Intent intent1 = new Intent(v.getContext(), FileChooser.class);
startActivityForResult(intent1, REQUEST_PATH);
}
}
);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
// See which child activity is calling us back.
if (requestCode == REQUEST_PATH)
{
if (resultCode == Activity.RESULT_OK)
{
curFileName = data.getStringExtra("GetFileName");
filePath=data.getStringExtra("GetPath");
edittext.setText(filePath);
}
}
}

lots of ways . here are 2 sample-
String someFilepath = "image.fromyesterday.test.jpg";
String extension = someFilepath.substring(someFilepath.lastIndexOf("."));
So in you case, it should be something like that
String extension = ff.getAbsolutePath().substring(ff.getAbsolutePath().lastIndexOf("."));
In case if you don't want to do it yourself-
use FilenameUtils.getExtension from Apache Commons IO-
String extension = FilenameUtils.getExtension("/path/to/file/mytext.txt");
or in your case -
String extension = FilenameUtils.getExtension(ff.getAbsolutePath());

You could just do it with one line of code using MIME Type Map.
First grab the file:
Uri file = Uri.fromFile(new File(filePath));
Then
String fileExt = MimeTypeMap.getFileExtensionFromUrl(file.toString());

You can put your code in your activity like this:
private String getfileExtension(Uri uri)
{
String extension;
ContentResolver contentResolver = getContentResolver();
MimeTypeMap mimeTypeMap = MimeTypeMap.getSingleton();
extension= mimeTypeMap.getExtensionFromMimeType(contentResolver.getType(uri));
return extension;
}
"uri" is the file uri from the result of "Browse button" selected file

Kotlin Approach:
val fileExtention: String = file.extension
Check this: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/java.io.-file/extension.html

Function:
public String getExt(String filePath){
int strLength = filePath.lastIndexOf(".");
if(strLength > 0)
return filePath.substring(strLength + 1).toLowerCase();
return null;
}
Usage:
String ext = getExt(path);
if(ext != null && ext.equals("txt")){
// do anything
}
PS: If you don't use toLowerCase(), possible the function returns upper and lower cases (dependent the exists file).

In Kotlin
You can read the MimeTypeMap documentation here
This is example if you are using startActivityForResult and you get data from it. Then you define Content Resolver to get mime type from the uri.
val uri: Uri? = it.data?.data
val contentResolver = requireContext().contentResolver
val stringMimeType = contentResolver.getType(uri!!)
Using that code, if you choose pdf file you will get something like
"application/pdf"
After that, using the MimeTypeMap you'll get the extensions. Don't forget that you should add getSingleton() because it's only available in singleton.
val stringFileType = MimeTypeMap.getSingleton().getExtensionFromMimeType(stringMimeType)

I used DocumentFile to get the file name and extension
DocumentFile documentFile = DocumentFile.fromSingleUri(YourActivity.this, fileUri);
String fileName = documentFile.getName();
String extension = fileName.substring(fileName.lastIndexOf("."));
For example, if your file name is 'your_image.jpg' then the extension will be '.jpg'

In Java
public String getFileExt(String fileName) {
return fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
}
In Kotlin
fun getFileExt(fileName: String): String? {
return fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length)
}

Kotlin
import android.webkit.MimeTypeMap
MimeTypeMap.getFileExtensionFromUrl("my.xlsx") // xlsx
MimeTypeMap.getFileExtensionFromUrl("my.pdf") // pdf
MimeTypeMap.getFileExtensionFromUrl("http://www.google.com/my.docx") // docx
MimeTypeMap.getFileExtensionFromUrl(File.createTempFile("aaa", ".txt").absolutePath) // txt

Getting extension of file in Kotlin:
fun getExtension(fileName: String): String {
return fileName.substring(if (fileName.lastIndexOf(".") > 0) fileName
.lastIndexOf(".") + 1 else return "",fileName.length)
}

getContentResolver().getType(theReceivedUri); // return "media/format"

Android - no app found to open link within Edittext

If I click on the HYPERLINK, I get a dialog with the message that no app was found to handle this link, but I know that my android device has some applications to handle this file, becuase I open this file already by click the file itself. Here the code snippet:
case DragEvent.ACTION_DROP:
final String DATA = event.getClipData().getItemAt(0).getText().toString();
final String RECORDS_DIR = ((ScribeApplication ) getApplication()).RECORDS_DIRECTORY_ABSOLUTE_PATH;
final Spanned HYPERLINK = Html.fromHtml("" + RECORDS_DIR + DATA + "");
editor.setMovementMethod(LinkMovementMethod.getInstance());
if (editor.length() > 0)
{
editor.append("\n");
editor.append(HYPERLINK);
}
else
editor.append(HYPERLINK);
return true;
DATA is the file name e.g. record1.3pg
RECORDS_DIR is the absolute path to the directory with the recording files.
HYPERLINK is the absolute path of a record file.
editor is an instance of Eidttext
As mentioned above, if I navigate to the records directory and click the record file itself I get an app chooser and can select an app to handle this record file. So what I did wrong that I dont get an app chooser by clicking the hyperlink within the edittext but rather an dialog with the failure that no app was found?
Many thanks in advance!

Here is my solution for the issue described by CommonsWare:
public class ClickableIntentURLSpan extends URLSpan
{
private Context context;
private Intent intent;
public ClickableIntentURLSpan(final Context CONTEXT, final String URL, final Intent INTENT)
{
super(URL);
final boolean INPUT_OK = (CONTEXT != null) && (INTENT != null);
if (INPUT_OK)
{
context = CONTEXT;
intent = INTENT;
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
}
else
throw new IllegalArgumentException("Illegal refer to null.");
}
#Override
public void onClick(final View VIEW)
{
context.startActivity(intent);
}
}
case DragEvent.ACTION_DROP:
final String DATA = event.getClipData().getItemAt(0).getText().toString();
final String RECORDS_DIR = ((ScribeApplication ) getApplication()).RECORDS_DIRECTORY_ABSOLUTE_PATH;
final String ABSOLUTE_URL = "file://" + RECORDS_DIR + '/' + DATA;
final Intent PLAY_RECORD_INTENT = new Intent(Intent.ACTION_VIEW);
final File RECORD_FILE = new File(RECORDS_DIR, DATA);
PLAY_RECORD_INTENT.setDataAndType(Uri.fromFile(RECORD_FILE), "audio/*");
final ClickableIntentURLSpan INTENT_URL = new ClickableIntentURLSpan(getApplicationContext(), ABSOLUTE_URL, PLAY_RECORD_INTENT);
final SpannableString HYPERLINK = new SpannableString(DATA);
HYPERLINK.setSpan(INTENT_URL, 0, DATA.length(), 0);
editor.setMovementMethod(LinkMovementMethod.getInstance());
if (editor.length() > 0)
{
editor.append("\n");
editor.append(HYPERLINK);
}
else
editor.append(HYPERLINK);
return true;

Android - Configurable directory?

One of the steps in building my app is to let the user select a folder in which some files are stored. How can i make this configurable, without hardcoding the directory. Is there any 3rd party library that i can use to do this ?

#Vikram's link provides a dialog that you can use. You can then save the directory the user chose using Shared Preferences.
Here is a simple example on how to use Shared Preferences.
Another tutorial can be found here.
UPDATE: A switch suddenly turned on inside me to do something like this. Credits still go to schwiz in this answer for the base code used. :)
//global variables
private File[] fileList;
private String[] filenameList;
private File[] loadFileList(String directory) {
File path = new File(directory);
if(path.exists()) {
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String filename) {
//add some filters here, for now return true to see all files
//File file = new File(dir, filename);
//return filename.contains(".txt") || file.isDirectory();
return true;
}
};
//if null return an empty array instead
File[] list = path.listFiles(filter);
return list == null ? new File[0] : list;
} else {
return new File[0];
}
}
public void showFileListDialog(final String directory, final Context context) {
Dialog dialog = null;
AlertDialog.Builder builder = new Builder(context);
File[] tempFileList = loadFileList(directory);
//if directory is root, no need to up one directory
if(directory.equals("/")) {
fileList = new File[tempFileList.length];
filenameList = new String[tempFileList.length];
//iterate over tempFileList
for(int i = 0; i < tempFileList.length; i++) {
fileList[i] = tempFileList[i];
filenameList[i] = tempFileList[i].getName();
}
} else {
fileList = new File[tempFileList.length+1];
filenameList = new String[tempFileList.length+1];
//add an "up" option as first item
fileList[0] = new File(upOneDirectory(directory));
filenameList[0] = "..";
//iterate over tempFileList
for(int i = 0; i < tempFileList.length; i++) {
fileList[i+1] = tempFileList[i];
filenameList[i+1] = tempFileList[i].getName();
}
}
builder.setTitle("Choose your file: " + directory);
builder.setItems(filenameList, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
File chosenFile = fileList[which];
if(chosenFile.isDirectory()) {
showFileListDialog(chosenFile.getAbsolutePath(), context);
}
}
});
builder.setNegativeButton("Cancel", new OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
dialog = builder.create();
dialog.show();
}
public String upOneDirectory(String directory) {
String[] dirs = directory.split(File.separator);
StringBuilder stringBuilder = new StringBuilder("");
for(int i = 0; i < dirs.length-1; i++) {
stringBuilder.append(dirs[i]).append(File.separator);
}
return stringBuilder.toString();
}
The code above acts like a mini file explorer that lists the files and folders of the Android File System. You use it like:
showFileListDialog(Environment.getExternalStorageDirectory().toString(),
MainActivity.this);
Answering your question:
Add global key variables
//package name goes here.
public static final String PACKAGE_NAME = "com.example.app";
public static final String KEY_DIRECTORY_SELECTED =
PACKAGE_NAME + ".DIRECTORY_SELECTED";
private SharedPreferences prefs;
initialize your SharedPreferences somewhere on onCreate before you use it:
prefs = getSharedPreferences(PACKAGE_NAME, Context.MODE_PRIVATE);
and then you can add a positive button to the dialog
builder.setPositiveButton("Save Directory", new OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
prefs.edit().putString(KEY_DIRECTORY_SELECTED, directory).commit();
}
});
In your activity, instead of using the SDCard default directory you can
//if no saved directory yet, use SDCard directory as default
String oldChosenDirectory = prefs.getString(KEY_DIRECTORY_SELECTED,
Environment.getExternalStorageDirectory().toString());
showFileListDialog(oldChosenDirectory, MainActivity.this);
As Vikram pointed out. you also need to do this in your FileNameFilter so that the dialog will display directories ONLY.
Update: As noted in this SO answer, the parameters dir and filename does not refer to the same file. The dir parameter is the directory containing the file, while filename is the filename of the file itself. To determine whether the filte itself is a directory, we need to create a new file from the parameters like so:
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String filename) {
File file = new File(dir.getAbsolutePath() + File.separator + filename);
return file.isDirectory();
}
};