Develop Reference

Why cant i load the image in picasso?

The actual code is very simple like this but doesnt works!!
File f = new File("file://E:/test.jpeg");
Picasso.with(this).load(f).
into(avatar);

File f = new File("file://E:/test.jpeg");
First, Android does not have drive letters, let alone an E: drive. That is not a valid filesystem path to any file on any Android device.
Second, the File constructor takes a filesystem path, not a Uri with a scheme (e.g., file://).

Its important to know that the file you are accessing has to be on your DEVICE and NOT from your computer. There is no such directory as a E: drive on phones.
You have a few options. Store the image online, and load it with Picasso (the easiest).
Picasso.with(getActivity())
.load("http://www.image_url.com/image.png")
.into(avatar);
Or, you can get the file path of an image, and then use that with picasso.
File file = new File("path-to-image/image.png")
Picasso.with(getActivity()).load(file).into(avatar);
How do you get the path-to-image of an image on your device?
You can follow this http://www.limbaniandroid.com/2014/03/how-to-get-absolute-path-when-select.html

Android create file without saving

File tempFile = File.createTempFile(""+Common.getMobileNumber(), ".jpg", null);
FileOutputStream fos = new FileOutputStream(tempFile);
fos.write(bos.toByteArray());
I do this, but thing is ...when i go to apps, and click on my app... i see that its adding caching. and this particular file is caching, how can i create file without caching/saving.
only need of file for me, is to send it over to server side. Is there any way i create a object file without saving/caching?

If you are saying you need like a file only in the memory for the particular task like uploading to server. It is very similar to this question to do that. There is a code to create a file in memory.
Android Creating a memory resident input file that can be attached to an email

Can't find file downloaded by download manager in android

I'm trying to download a file to directory that can vary based on whichever directory the user chooses. I store the current directory in a file object and now attempting to download the file. The file downloads, but it doesn't download the specified directory. So, what can I do to get the file in the directory selected.
// Getting path to store the file
String path = root.getAbsolutePath();
path += curr.getName();
request.setDestinationInExternalPublicDir(path, new File(url).getName());
// get download service and enqueue file
DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
manager.enqueue(request);
The String named url, that is being passed to the File constructor, contains a URL. Just using that to retrieve that name of the file.
UPDATE:
I just found the file. Its in the phone not the sd card. It was in this folder, storage\emulated\00. Not sure why? Also, the absolute path that I'm getting is storage\emulated\0.

So, I figured out that the path returned is always storage\emulated\0 for the call getExternalStorageDirectory().getPath()) to the Environment. Which is what I using to the get the initial directory. So for instance if I navigated through the folders to the Downloads folder the path would be storage\emulated\0\Download. When I was downloading the file though instead of going to the actual downloads folder it would go to, or create, the downloads folder in the emulated folder in the storage folder. To resolve this I found the index of the zero in the path, added 1, and got the substring using that. After that it worked. Also I had to do this in another method where I navigate through the directory. As a parameter I pass in the file and then within the method I get the substring. Within the method that I use to download the file I get storage\emulated\0 no matter what. Not sure why it does this. If anyone could explain this it would be greatly appreciated.

Does root.getAbsolutePath() return a string with a path separator character at the end?
If not, then you might be doing something like bin/usr/var/appfilename.ext instead of bin/usr/var/app/filename.ext, because you're concatenating it straight into name of the file.

I still had this issue on Android 7. In my case, the file would not show up until I restart the device. This a known issue: https://issuetracker.google.com/issues/36956498
Source: https://stackoverflow.com/a/20413888/2552811

android assetManager

I need to get Absolute path to Folder in Assets.
Some like this for sd-card:
final String sdDir = Environment.getExternalStorageDirectory() + "Files";
What i do incorrect?
First I try to get path (in green ractangle) this way but I alwase get "False".
Then I comment this block and try to get path from getAssets().list();
But I get 3 folders witch I see first time.
I want to make massive like this "green" but I need to use files from assets:
Look the image
Help me to get absolute path to my Files folder.

I'm not exactly sure what you're trying to do, so I'll try to cover the bases, and maybe this will help.
If you are just trying to get a list of what's in your assets, then
use getAssets().list("Files"). (You have to use the subdirectory,
because of this).
If you are trying to get an absolute path to your assets directory
(or any subdirectory), you can't. Whatever is in the assets directory
is in the APK. It's not in external storage like on an SD card.
If you are trying to open up files in the assets directory, use
AssetManager.open(filename) to get the InputStream. Here,
filename should be the relative path from the assets directory.
EDIT
I'm not sure what you mean by "massive", but if you want to load the file black.png from assets instead of the SD card, then write this:
// must be called from Activity method, such as onCreate()
AssetManager assetMgr = this.getAssets();
mColors = new Bitmap[] {
BitmapFactory.decodeStream(assetMgr.open("black.png"));
// and the rest
};

Assets are stored in the APK file so there are no absolute path than your application can use. But, I would suggest to take a look at file:///android_asset. It might fits your needs. Here is a good example on how to display an Asset in a WebView.

android: Check the existence of a file in the application

I have few html files in assets folder of my application. My application loads these files depending on the device language. When I check for the existance of the file it say does not exist, but when I load that file using browser.loadUrl(filename), it loads it fine.
Following code will help you to understand my problem:
String filename="file:///android_asset/actualfilemname.html";
File f = new File(filename);
if(!f.exist){
filename = "file:///android_asset/newfile.html";[Everytime it loads this file even though I have actualfilename.html in the folder]
}
browser.loadUrl(filename);
[it loads the newfile.html but not actualfilename.html]

You can't use File for resources. You'll need to use the AssetManager for that.
(In the off-chance that File does handle resources, which I don't think it does, you'll have to convert the path to a URI first, for example using URI.create(). File(String) expects a path, not a URI.)

Is this the exact code you are using? you probably want to be calling f.exists() not filename.exist().
Edit: try working with the AssetManager instead of hard coding your file path. My best guess is that the file path you are using is not exactly how it supposed to be.