I'm trying to create an app and have the ability to save files to /data/data/(packagename)/files or a directory similar to that. The goal would be to have a pdf or doc handler, as necessary, open the files stored on the internal storage and be viewed by the user. I have the code to get a pdf reader that is installed and display the file but I do not know how to package the files so they are installed in a directory like the one above. Also, if I am able to do this would I use getResources to access the files? How should the file structure look in eclipse to make this happen on install of the APK?
I do prefer to have the files stored internally (they are small) and not on the SD card.
I admit I am new to this and am trying to learn as I go. Thanks for the help!
As I understand your approach you only need to place your files to assets folder of your application and then just copy them to the internal storage. Read more here.
Related
I need to open a file in libgdx for random access, i.e. I need to be able to seek() to different parts of the file (not read sequentially).
Using libgdx I am able to access the file via Gdx.files.internal(), but libgdx's filehandlers don't support random access methods like seek(). I tried using java.io.RandomAccessFile, but it generates the exception No such file or directory, probably because the file is stored internally in the jar file.
How can I access the file using java.io.RandomAccessFile` or alternatively how can i open file for random-access in libgdx?
This needs to work on both Android and desktop platforms.
This is not a Libgdx limitation. You cannot do random access on files stored inside a JAR file (since they're compressed, you need to stream the contents). (I can't find a concise reference for this, but look at the definitions of JarFile and ZipFile: they only let you create streaming file handles).
Libgdx itself runs into this problem. It stores native libraries in a .jar file (the libgdx-natives.jar). To use the files, it extracts them to the local filesystem and uses them from there. See SharedLibraryLoader.java.
As far as I can tell there are three workarounds to chose from:
Remove the need for the random access in your code.
Stream the file from the JAR into memory, and randomly access it there
Copy the file from the JAR into local (private) storage or temp storage (hopefully this could be done once and not re-done on each run of the app).
I am currently developing an android application that useLibsvm library for data
classification.
To use the Libsvm I should provide file text describing data
the size of my data=1,3G
I have placed all my files in assets Folder => copied them in sdCard and then running the
classification
The problem Now is that my application take a lot of time to be installed on my device!
It is possible to compress those files and the decompress them while running my
classification?
And How to do this in Android
move your resources to desktop and delete them from your app, this would be helpful for testing your app.
You could zip the file on the installation and make your service unzips it the first time it's used.
You may zip/unzip using the java.util.zip standard package.
i am building a project in which i have to retrieve text content of a file,i read this article https://developers.google.com/appengine/docs/java/gettingstarted/staticfiles .in this article i can store file in the war/ directory and access it.but it is publicly accessible any one can access this file my file contain some sensitive data where to store this file and how to access it?? please guideline!!
You need to designate static file as described here:
https://developers.google.com/appengine/docs/java/config/appconfig#Static_Files_and_Resource_Files
You can definitely store statis files and process them as required in your application. Please keep your files into a folder that is not directly accessible by others.
I suggest the following:
Keep the files inside of /WEB-INF/myfiles or some folder like that inside of the /WEB-INF folder.
Use the File APIs to read the content of the files.
Hope this helps.
I have a swing application that uses many data files, these data files will change time to time. How can I load these data files on client's machine? Is there any way to create a folder like structure and run a batch file or so? Any help is appreciated.
There are several ways to do this:
Assume you want to ship your application with the datafiles, you may embed them as a zip/jar in your application-jar-file.
Extract the embedded zip to a temporary local file and use ZipFileSystemProvider to extract the content to some place on the disc.
Here is an example how to extract some content from zip/jar-file embedded in a .jar-file downloaded by JWS.
Same as 1, but skip the zip stuff and instead provide a list of all the resources you want to extract
One other way is to create the files pragmatically using either java.nio.file (java 7+) or java.io.File
According to current requirement,user will upload files with large size,which he may like to download later. I cannot store the uploaded files in DB because the size of files is large and performance will be impacted if I store uploaded files in DB.
Any one knows any java plugin which provide efficient file management on webserver and maintains the link to file so that the file can be downloaded when the link is requested. Also the code will make sure that user will be able to download only those files which is uploaded by them,they cannot download any file just by modifying the download link etc. I am using spring3 as the framework.
Please suggest how to solve this problem?
if you have write access to the file system why not just save them there ?
you then generate an unique ID and save the hash/file relation in db, you then need to supply the ID to get the file feed from a servlet
Store the file content on a part of filesystem out of web application so you cannot reach it changing the link.
Then you can store on db the path for that file, and return them only if the user has the permissions to read it.
Pay attention, do not store all the file on the same folder, or the number of files could grow too much. So find a way to store them with more folder levels.