Develop Reference

Can't read lines from file by using StreamReader on Unity3d (Android)

I need to read a text stream by using StreamReader from file on android platform. File is about 100k lines, so even editor is getting stuck if i try to load it all to TextAsset or if i use WWW.
I simply need to read that file line by line without loading it all to a string. Then i'll do a tree generation from the lines that i got from the file. (But probably that part doesn't matter, i just need help on file reading part.)
I'm giving the code that i wrote down below. It works perfectly on editor, but fails on android.
I would be glad if anyone tell me, what am i missing.
(ps. english is not my native and this is my first question on the site. so sorry for the any mistakes that i may have done.)
private bool Load(string fileName)
{
try
{
string line;
string path = Application.streamingAssetsPath +"/";
StreamReader theReader = new StreamReader(path + fileName +".txt", Encoding.UTF8);
using (theReader)
{
{
line = theReader.ReadLine();
linesRead++;
if (line != null)
{
tree.AddWord(line);
}
}
while (line != null);
theReader.Close();
return true;
}
}
catch (IOException e)
{
Debug.Log("{0}\n" + e.Message);
exception = e.Message;
return false;
}
}

You can't use Application.streamingAssetsPath as a path on Android because streaming assets are stored within the JAR file with the application.
From http://docs.unity3d.com/Manual/StreamingAssets.html:
Note that on Android, the files are contained within a compressed .jar
file (which is essentially the same format as standard zip-compressed
files). This means that if you do not use Unity’s WWW class to
retrieve the file then you will need to use additional software to see
inside the .jar archive and obtain the file.
Use WWW like this in a coroutine:
WWW data = new WWW(Application.streamingAssetsPath + "/" + fileName);
yield return data;
if(string.IsNullOrEmpty(data.error))
{
content = data.text;
}
Or, if you really want to keep it simple (and your file is only a few 100k, stick it in a resource folder:
TextAsset txt = (TextAsset)Resources.Load(fileName, typeof(TextAsset));
string content = txt.text;

Access WordNet dict files in Android app

I'm writing a word game in Android. It's my first app so my knowledge is almost non-existent.
What I would like to do is use JWI to access the WordNet dictionary. This requires specifying the WordNet dictionary's file path.
From what I've read, Android "assets" are not available via a simple file path, but what JWI requires to initialize the WordNet dictionary API is a URL to the disk location of the dictionary files.
So, what is the best course of action? Should I copy the assets at startup-time into a known folder on the android device? I can't think of a better way but that seems entirely stupid to me.
Any help gratefully received.

I have the same problem (for a jetty webapp however and not android) and tried those two approaches, however unsuccessfully:
JWNL.initialize(this.getClass().getClassLoader().getResourceAsStream("wordnet_properties.xml");
dict = Dictionary.getInstance();
Here it successfully loads wordnet_properties.xml but it cannot access the dictionary which is pointed to by the properties file.
Using the dictionary folder directly:
String dictPath = "models/en/wordnet/dict/";
URL url = this.getClass().getClassLoader().getResource(dictPath);
System.out.println("loading wordnet from "+url);
dict = new RAMDictionary(url, ILoadPolicy.NO_LOAD);
Here I get the dictionary URL to be jar:file:/home/myusername/.m2/repository/package/1.0-SNAPSHOT/commons-1.0-SNAPSHOT.jar!/models/en/wordnet/dict/. WordNet however doesn't accept the jar protocol and gives me the error:
java.lang.IllegalArgumentException: URL source must use 'file' protocol
at edu.mit.jwi.data.FileProvider.toFile(FileProvider.java:693)
at edu.mit.jwi.data.FileProvider.open(FileProvider.java:304)
at edu.mit.jwi.DataSourceDictionary.open(DataSourceDictionary.java:92)
at edu.mit.jwi.RAMDictionary.open(RAMDictionary.java:216)
My next investigation will be to create a subclass to RAMDictionary or something similar, please tell me if you have found a solution in the meantime.
P.S.: I just wrote the developer a mail asking for help after I tried to rewrite the FileProvider to use resources instead but after one or two hours I gave up because the code calls so much other code that also only works with files. I will keep you up to date!
P.P.S.: I received an answer from the developer saying that it is principially not possible with streams because they don't offer random access which is necessary. However, he offered to implement a solution to load it all in RAM, if really necessary, but that would use up about 500 MB and I guess that is too much for android apps so I guess it is still best to unpack it somewhere.
P.S.: Here is my unpacking solution (you can replace the System.out.println statements with logger statements if you use logging or remove them if you don't like them):
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
/** Allows WordNet to be run from within a jar file by unpacking it to a temporary directory.**/
public class WordNetUnpacker
{
static final String ID = "178558556719"; // minimize the chance of interfering with an existing directory
static final String jarDir = "models/en/wordnet/dict";
/**If running from within a jar, unpack wordnet from the jar to a temp directory (if not already done) and return that.
* If not running from a jar, just return the existing wordnet directory.
* #see getUnpackedWordNetDir(Class)*/
static File getUnpackedWordNetDir() throws IOException
{return getUnpackedWordNetDir(WordNetUnpacker.class);}
/**If running from within a jar, unpack wordnet from the jar to a temp directory (if not already done) and return that.
* If not running from a jar, just return the existing wordnet directory.
* #param clazz the class in whose classloader the wordnet resources are found.
* #see getUnpackedWordNetDir()**/
static File getUnpackedWordNetDir(Class clazz) throws IOException
{
String codeSource = clazz.getProtectionDomain().getCodeSource().getLocation().getPath();
System.out.println("getUnpackedWordNetDir: using code source "+codeSource);
if(!codeSource.endsWith(".jar"))
{
System.out.println("not running from jar, no unpacking necessary");
try{return new File(WordNetUnpacker.class.getClassLoader().getResource(jarDir).toURI());}
catch (URISyntaxException e) {throw new IOException(e);}
}
try(JarFile jarFile = new JarFile(codeSource))
{
String tempDirString = System.getProperty("java.io.tmpdir");
if(tempDirString==null) {throw new IOException("java.io.tmpdir not set");}
File tempDir = new File(tempDirString);
if(!tempDir.exists()) {throw new IOException("temporary directory does not exist");}
if(!tempDir.isDirectory()) {throw new IOException("temporary directory is a file, not a directory ");}
File wordNetDir = new File(tempDirString+'/'+"wordnet"+ID);
wordNetDir.mkdir();
System.out.println("unpacking jarfile "+jarFile.getName());
copyResourcesToDirectory(jarFile, jarDir, wordNetDir.getAbsolutePath());
return wordNetDir;
}
}
/** Copies a directory from a jar file to an external directory. Copied from Stack Overflow. */
public static void copyResourcesToDirectory(JarFile fromJar, String jarDir, String destDir) throws IOException
{
int copyCount = 0;
for (Enumeration<JarEntry> entries = fromJar.entries(); entries.hasMoreElements();)
{
JarEntry entry = entries.nextElement();
if(!entry.getName().contains("models")) continue;
if (entry.getName().startsWith(jarDir) && !entry.isDirectory()) {
copyCount++;
File dest = new File(destDir + "/" + entry.getName().substring(jarDir.length() + 1));
File parent = dest.getParentFile();
if (parent != null) {
parent.mkdirs();
}
FileOutputStream out = new FileOutputStream(dest);
InputStream in = fromJar.getInputStream(entry);
try {
byte[] buffer = new byte[8 * 1024];
int s = 0;
while ((s = in.read(buffer)) > 0) {
out.write(buffer, 0, s);
}
} catch (IOException e) {
throw new IOException("Could not copy asset from jar file", e);
} finally {
try {
in.close();
} catch (IOException ignored) {}
try {
out.close();
} catch (IOException ignored) {}
}
}
}
if(copyCount==0) System.out.println("Warning: No files copied!");
}
}

You can just copy all dict files from "assets" to the internal directory of your app. Just do it once, on the first app launch.
Since then you can use JWI in a causual way like this:
String path = getFilesDir() + "/dict";
URL url = new URL("file", null, path);
IDictionary dict = new Dictionary(url);

Upload files from a folder to a FTP-Server. I've get two errors. How can I solve these errors?

I'm working on a FTP-Client.
I've already created an FTP-Client based by this one: Android How to upload a file via FTP
With this code. It was possible to send a txt-File with an included string to my FTP-Server.
I've got pictures in my local folder "/sdcard/ftp/"
Now I'm trying to change the code, that it is possible that all the jpg-files in the folder will be send by ftp client.
package de.android.datenuebertragung;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPConnectionClosedException;
import org.apache.commons.net.ftp.FTPFile;
import android.app.Activity;
import android.util.Log;
public class FTPManager extends Activity{
FTPClient con = new FTPClient();{
try
{
con.connect("host");
if (con.login("user", "password"))
{
// in application never use hardcoded paths
File folder = new File("/sdcard/ftp/");
File tempFile = null;
FTPFile[] tempFTPFile = null;
//get all files in folder
for(String fileInDir : folder.list()){
tempFile = new File(fileInDir);
tempFTPFile = con.listNames(tempFile.getFiles);
if(tempFTPFile!=null || tempFTPFile.length<=0){
con.upload(fileInDir);
}
}
}
}
catch (Exception e)
{
e.printStackTrace();
}
try
{
con.logout();
con.disconnect();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
I've got two errors in the these marked words (getFiles and upload):
tempFTPFile = con.listNames(tempFile.getFiles);
con.upload(fileInDir);
The error in con.listNames(tempFile.getFiles) is: getFiles cannot be resolved or is not a field
and the another error in con.upload(fileInDir) is: The method upload(String) is undefined for the type FTPClient
I've tried the whole day to solve this problem. Hope someone can help me. Maybe post the changed and worked code. I'm an absolutley newbie in Android programming.

If you've pasted your code directly and there isn't a typo then it should be getFiles() and not getFiles in this line...
tempFTPFile = con.listNames(tempFile.getFiles);
Also, I suspect the default transfer mode will be ASCII (this is usually the case for any FTP client software).
Try calling...
con.setFileType(FTP.BINARY_FILE_TYPE);
...before attempting the uploads.

determine whether android asset entry is a file or directory

Hej,
I have some data shipped out with the app which shall be copied on the external storage. It's nested in a couple of subfolders and I'd like to copy the whole structure.
I'm having a hard time getting a File object for any ressource in /assets. But I think I'm depended on that 'cause I need something like File.isDirectory() to determine if I have to start copying or dive deeper into the system.
My first approach was using Assets Manager but it seems that class is not providing the information I need. The most promising why was to obtain an AssetFileDescriptorand go down to a [FileDescriptor][2]. However non of them seems to have a isDirectory-method.
So my other approach is straight forward: Creating a File Object and be happy. However it seems like I'm running in this problem of lacking a proper path to instance the file object. I'm aware of file://android_asset but it doesn't seem to work for the fileconstructor.
My last idea would to utilise the InputStream (which I need for copying anyway) and somehow filter the byte for a significant bit which indicates this resource to be a directory. That's a pretty hacky solution and probably right in the hell of ineffectiveness but I don't see another way to get around that.

I had the same problem. At some point I realized that list() is really slow (50ms on every call), so i'm using a different approach now:
I have an (eclipse) ant-builder which creates an index-file everytime my asset-folder changes. The file just contains one file-name per line, so directories are listed implicitely (if they are not empty).
The Builder:
<?xml version="1.0"?>
<project default="createAssetIndex">
<target name="createAssetIndex">
<fileset id="assets.fileset" dir="assets/" includes="**"
excludes="asset.index" />
<pathconvert pathsep="${line.separator}" property="assets"
refid="assets.fileset">
<mapper>
<globmapper from="${basedir}/assets/*" to="*"
handledirsep="yes" />
</mapper>
</pathconvert>
<echo file="assets/asset.index">${assets}</echo>
</target>
</project>
The class which loads asset.index into a List of Strings, so you can do arbitrary stuff with it, fast:
import android.content.ContextWrapper;
import com.google.common.collect.ImmutableList;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* uses asset.index file (which is pregenerated) since asset-list()s take very long
*
*/
public final class AssetIndex {
//~ Static fields/initializers -------------------------------------------------------------------------------------
private static final Logger L = LoggerFactory.getLogger(AssetIndex.class);
//~ Instance fields ------------------------------------------------------------------------------------------------
private final ImmutableList<String> files;
//~ Constructors ---------------------------------------------------------------------------------------------------
public AssetIndex(final ContextWrapper contextWrapper) {
ImmutableList.Builder<String> ib = ImmutableList.builder();
L.debug("creating index from assets");
InputStream in = null;
Scanner scanner = null;
try {
in = contextWrapper.getAssets().open("asset.index");
scanner = new Scanner(new BufferedInputStream(in));
while (scanner.hasNextLine()) {
ib.add(scanner.nextLine());
}
scanner.close();
in.close();
} catch (final IOException e) {
L.error(e.getMessage(), e);
} finally {
if (scanner != null) {
scanner.close();
}
if (in != null) {
try {
in.close();
} catch (final IOException e) {
L.error(e.getMessage(), e);
}
}
}
this.files = ib.build();
}
//~ Methods --------------------------------------------------------------------------------------------------------
/* returns the number of files in a directory */
public int numFiles(final String dir) {
String directory = dir;
if (directory.endsWith(File.separator)) {
directory = directory.substring(0, directory.length() - 1);
}
int num = 0;
for (final String file : this.files) {
if (file.startsWith(directory)) {
String rest = file.substring(directory.length());
if (rest.charAt(0) == File.separatorChar) {
if (rest.indexOf(File.separator, 1) == -1) {
num = num + 1;
}
}
}
}
return num;
}
}

list() on AssetManager will probably give a null / zero length array / IOException if you try to get a list on a file, but a valid response on a directory.
But otherwise it should be file:///android_asset (with 3 /)

In my specific case, regular files have a name like filename.ext, while directories only have a name, without extension, and their name never contains the "." (dot) character.
So a regular file can be distinguished from a directory by testing its name as follows:
filename.contains(".")
If this your case too, the same solution should work for you.

Copy the shared preferences XML file from /data on Samsung device failed

There's an exporting feature in my application. It's just a copy operation since all my settings are store in shared preference.
I just copy the xml file from /data/data/package.name/shared_prefs/settings.xml to SD card. It works fine on my HTC desire. However, it might not work on Samsung devices, and i got the following error while I try to copy the file.
I/System.out( 3166): /data/data/package.name/shared_prefs/settings.xml (No such file or directory)
in the directory.
Anyone know how to fix it, or is there another simple way to store the shared preference ?
Thanks.

Never never never never never never never never never hardwire paths.
Unfortunately, there's no getSharedPreferenceDir() anywhere that I can think of. The best solution I can think of will be:
new File(getFilesDir(), "../shared_prefs")
This way if a device manufacturer elects to change partition names, you are covered.
Try this and see if it helps.

CommonsWare's suggestion would a be clever hack, but unfortunately it won't work.
Samsung does not always put the shared_prefs directory in the same parent directory as the getFilesDir().
I'd recommend testing for the existence of (hardcode it, except for package name):
/dbdata/databases/<package_name>/shared_prefs/package.name_preferences.xml and if it exists use it, otherwise fall back to either CommonsWare's suggestion of new File(getFilesDir(), "../shared_prefs") or just /data/data/<package_name>/shared_prefs/package.name_preferences.xml.
A warning though that this method could potentially have problems if a user switched from a Samsung rom to a custom rom without wiping, as the /dbdata/databases file might be unused but still exist.
More details
On some Samsung devices, such as the Galaxy S series running froyo, the setup is this:
/data/data/<package_name>/(lib|files|databases)
Sometimes there's a shared_prefs there too, but it's just Samsung's attempt to confuse you! Don't trust it! (I think it can happen as a left over from a 2.1 upgrade to 2.2, but it might be a left over from users switching roms. I don't really know, I just have both included in my app's bug report interface and sometimes see both files).
And:
/dbdata/databases/<package_name>/shared_prefs
That's the real shared_prefs directory.
However on the Galaxy Tab on Froyo, it's weird. Generally you have: /data/data/<package_name>/(lib|shared_prefs|files|databases)
With no /dbdata/databases/<package_name> directory, but it seems the system apps do have:
/dbdata/databases/<package_name>/yourdatabase.db
And added bonus is that /dbdata/databases/<package_name> is not removed when your app is uninstalled. Good luck using SharedPreferences if the user ever reinstalls your app!

Try using
context.getFilesDir().getParentFile().getAbsolutePath()

Best way to get valid path on all devices - run method Context.getSharedPrefsFile defined as:
/**
* {#hide}
* Return the full path to the shared prefs file for the given prefs group name.
*
* <p>Note: this is not generally useful for applications, since they should
* not be directly accessing the file system.
*/
public abstract File getSharedPrefsFile(String name);
Because of it hidden need use reflection and use fallback on fail:
private File getSharedPrefsFile(String name) {
Context context = ...;
File file = null;
try {
if (Build.VERSION.SDK_INT >= 24) {
try {
Method m = context.getClass().getMethod("getSharedPreferencesPath", new Class[] {String.class});
file = (File)m.invoke(context, new Object[]{name});
} catch (Throwable e) {
Log.w("App TAG", "Failed call getSharedPreferencesPath", e);
}
}
if (file == null) {
Method m = context.getClass().getMethod("getSharedPrefsFile", new Class[] {String.class});
file = (File)m.invoke(context, new Object[]{name});
}
} catch (Throwable e) {
Log.w("App TAG", "Failed call getSharedPrefsFile", e);
file = new File(context.getFilesDir(), "../shared_prefs/" + name + ".xml");
}
return file;
}
On some Samsungs implements like this:
public File getSharedPrefsFile(String paramString) {
return makeFilename(getPreferencesDir(), paramString + ".xml");
}
private File getPreferencesDir() {
synchronized (this.mSync) {
if (this.mPreferencesDir == null) {
this.mPreferencesDir = new File("/dbdata/databases/" + getPackageName() + "/", "shared_prefs");
}
File localFile = this.mPreferencesDir;
return localFile;
}
}
On other Android like this:
public File getSharedPrefsFile(String name) {
return makeFilename(getPreferencesDir(), name + ".xml");
}
private File getPreferencesDir() {
synchronized (mSync) {
if (mPreferencesDir == null) {
mPreferencesDir = new File(getDataDirFile(), "shared_prefs");
}
return mPreferencesDir;
}
}
private File getDataDirFile() {
if (mPackageInfo != null) {
return mPackageInfo.getDataDirFile();
}
throw new RuntimeException("Not supported in system context");
}
After while Google change API for level 24 and later:
https://android.googlesource.com/platform/frameworks/base/+/6a6cdafaec56fcd793214678c7fcc52f0b860cfc%5E%21/core/java/android/app/ContextImpl.java

I've tested in Samsung P1010 with:
//I'm in a IntentService class
File file = this.getDir("shared_prefs", MODE_PRIVATE);
I got:
"/data/data/package.name/app_shared_prefs"
It works fine to me. I can run ffmpeg in this folder.
Look:
Context.getDir

You have to create the shared_prefs directory:
try{
String dir="/data/data/package.name/shared_prefs";
// Create one directory
boolean success = (new File(dir)).mkdirs();
if (success) {
// now copy the file
}
}catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
Also... the package of your app is package.name? Make sure you are referring to the right package.