Develop Reference

unzipping a file containing pictures in my app

I developed an app where I am backing up and restoring app data. The backup data is stored in .zip format in phone directory. While restoring I am unzipping the file till here everything works fine. But, if the backup contain images as data, while restoring they are not opening in app and giving an error. The code written for unzipping file is written as
public void DBimport(String inFileName) {
opener= new DataBaseOpener(mApp);
final String outFileName = mContext.getDatabasePath(opener.getDatabaseName()).toString();
try {
File dbFile = new File(inFileName);
FileInputStream fis = new FileInputStream(dbFile);
ZipInputStream zipInputStream= new ZipInputStream(fis);
ZipEntry zipEntry= zipInputStream.getNextEntry();
while(zipEntry!=null) {
String fileName=zipEntry.getName();
File newFile= new File(outFileName/* + File.separator + fileName*/);
new File(newFile.getParent()).mkdirs();
// Open the empty db as the output stream
OutputStream output = new FileOutputStream(newFile);
// Transfer bytes from the input file to the output file
byte[] buffer = new byte[1024];
int length;
while ((length = zipInputStream.read(buffer)) > 0) {
output.write(buffer, 0, length);
}
// Close the streams
output.flush();
output.close();
zipEntry=zipInputStream.getNextEntry();
}
zipInputStream.closeEntry();
fis.close();
Toast.makeText(mContext, "Restore Completed", Toast.LENGTH_LONG).show();
} catch (IOException e) {
Toast.makeText(mContext, "Unable to Restores. Retry", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
}
May I know where I am going wrong ? and how to resolve this issue. any suggestions will be helpful.

Setting permissions for created directory to copy files into it

During the execution of my program it creates a directory which contains two sub-directories/two folders. Into one of these folders I need to copy a Jar-File. My programm resembles an installation routine. The copying of the Jar file is not the problem here, but the permissions of the created directories.
I tried to set the permissions of the directories (before actually creating them with the mkdirs() method) with File.setWritable(true, false) and also with the .setExecutable and .setReadable methods, but the access to the sub-directories is still denied.
Here's an excerpt of my code for the creation of one of the two sub-directories:
folderfile = new File("my/path/to/directory");
folderfile.setExecutable(true, false);
folderfile.setReadable(true, false);
folderfile.setWritable(true, false);
result = folderfile.mkdirs();
if (result) {
System.out.println("Folder created.");
}else {
JOptionPane.showMessageDialog(chooser, "Error");
}
File source = new File("src/config/TheJar.jar");
File destination = folderfile;
copyJar(source, destination);
And my "copyJar" method:
private void copyJar(File source, File dest) throws IOException {
InputStream is = null;
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer))>0) {
os.write(buffer, 0, length);
}
} catch (Exception e) {
e.printStackTrace();
}
is.close();
os.close();
}
At os = new FileOutputStream(dest); the debugger throws a FileNotFoundException with the description that the access to the directory has been denied.
Does anyone have an idea what I am doing wrong or have a better solution for setting the permissions via Java? Thanks in advance!

A similar question was asked there are several years.
A possible solution for Java 7 and Unix system is available here : How do i programmatically change file permissions?
Or, below the best response, a example with JNA.
I hope that that will help you !

I solved the problem. In the end it was much easier to solve than expected.
The main problem was not the permission issue but the FileNotFoundException. The file that is assigned to the OutputStream is not really a file, but just a directory so that the Stream can't find it. You have to create the file before initializing the OutputStream and after that you copy your source file into the newly created file. The code:
private void copyJar(File source, File dest) throws IOException {
InputStream is = null;
File dest2 = new File(dest+"/TheJar.jar");
dest2.createNewFile();
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest2);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer))>0) {
os.write(buffer, 0, length);
}
} catch (Exception e) {
e.printStackTrace();
}
is.close();
os.close();
}

Writing to an External File on Android --- File Doesn't Register, But Java Can Read

I'm trying to write to an external txt (or csv) file for Android. I can run an app, close it, and run it again, and readData() will read back to my log what I've stored. However, the dirFile (file directory) appears nowhere within my Android files (even if I connect it to a computer and search).
Something interesting, though: if I clear my log (similar to a list of print statements shown within Eclipse) and disconnect my phone from my computer, then reconnect it, the log reappears with everything I've ever written to my file (even if I later overwrote it)...yet the app isn't even running!
Here is my code. Please help me understand why I cannot find my file!
(Note: I've tried appending a "myFile.txt" extension to the directory, but it just causes an EISDIR exception.)
public void writeData(String dirName){
try
{
File root = new File(getExternalFilesDir(null), dirName);
// Writes to file
//
// The "true" argument allows the file to be appended. Without this argument (just root),
// the file will be overwritten (even though we later call append) rather than appended to.
FileWriter writer = new FileWriter(root, true);
writer.append("Append This Text\n");
writer.flush();
writer.close();
// Checks if we actually wrote to file by reading it back in (appears in Log)
//readData(dirName);
}
catch(Exception e)
{
Log.v("2222", "2222 ERROR: " + e.getMessage());
}
}
If you're interested, here's the function I wrote to read in the data:
public void readData(String dirName){
try
{
File root = new File(getExternalFilesDir(null), dirName);
// Checks to see if we are actually writing to file by reading in the file
BufferedReader reader = new BufferedReader(new FileReader(root));
try {
String s = reader.readLine();
while (s != null) {
Log.v("2222", "2222 READ: " + s);
s = reader.readLine();
}
}
catch(Exception e) {
Log.v("2222", "2222 ERROR: " + e.getMessage());
}
finally {
reader.close();
}
}
catch(Exception e) {
Log.v("2222", "2222 ERROR: " + e.getMessage());
}
}
Thanks!

even if I connect it to a computer and search
if I clear my log (similar to a list of print statements shown within Eclipse) and disconnect my phone from my computer, then reconnect it, the log reappears with everything I've ever written to my file (even if I later overwrote it).
What you are seeing on your computer is what is indexed by MediaStore, and possibly a subset of those, depending upon whether your computer caches information it gets from the device in terms of "directory" contents.
To help ensure that MediaStore indexes your file promptly:
Use a FileOutputStream (optionally wrapped in an OutputStreamWriter), not a FileWriter
Call flush(), getFD().sync(), and close() on the FileOutputStream, instead of calling flush() and close() on the FileWriter (sync() will ensure the bytes are written to disk before continuing)
Use MediaScannerConnection and scanFile() to tell MediaStore to index your file
You can then use whatever sort of "reload" or "refresh" or whatever option is in your desktop OS's file manager, and your file should show up.
This blog post has more on all of this.

public void create(){
folder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES),"video");
boolean success = true;
if (!folder.exists()) {
success=folder.mkdirs();
}
if (success) {
readfile();
} else {
System.out.println("failed");
}
}
The above code will be used to crete the directory in th emobile at desired path
private void readfile() {
// TODO Auto-generated method stub
AssetManager assetManager = getResources().getAssets();
String[] files = null;
try {
files = assetManager.list("clipart");
} catch (Exception e) {
Log.e("read clipart ERROR", e.toString());
e.printStackTrace();
}
for(String filename : files) {
System.out.println("File name => "+filename);
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open("clipart/" + filename);
out = new FileOutputStream(folder + "/" + filename);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(Exception e) {
Log.e("copy clipart ERROR", e.toString());
e.printStackTrace();
}
}}private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}}
this is my code used to write file in internal memory from the assets folder in project. This code can read all type(extension) of file from asset folder to mobile.
Don't forget to add permission in manifest file
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
and call the above function by
readfile();//this call the function to read and write the file
I hope this may help you.
Thank you.

How to Read PNG from a jar packaged in a war

I am trying to write some code that allows me to access a file (specifically EMailBanner.png) that is wrapped as a jar and then included in a war.
The code I have cobbled together is as follows;
public static File getFile(String imagePath){
if(StringUtilities.stringEmptyOrNull(imagePath)){
throw new IllegalArgumentException("Invalid image path");
}
File tempFile = null;
InputStream is = null;
FileOutputStream fos = null;
try{
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
is = classLoader.getResourceAsStream(imagePath);
tempFile = File.createTempFile("EMailBanner", ".png");
tempFile.deleteOnExit();
fos = new FileOutputStream(tempFile);
byte[] buf = new byte[1024];
int len;
while ((len = is.read(buf)) != -1) {
fos.write(buf, 0, len);
}
}catch(IOException e ){
LOGGER.error("Unable to load image", e);
}catch(Exception e){
LOGGER.error("Unable to load image", e);
}finally{
try {
fos.close();
is.close();
} catch (IOException e) {
LOGGER.warn("Unable to close the file input / file output streams", e);
}
}
return tempFile;
}
The issue I am facing is that when deployed on to the development box as a war file - the application cannot find the png file. If I run locally in eclipse it isn't a problem.
Whats strange is I have a number of properties files in the resources folder as you can see from the image below;
I have no problems loading those from within the jar file - loaded like this;
public static Properties getDatabaseConnectionProps(ApplicationName appName) throws IOException{
if(appName == null){
throw new IllegalArgumentException("Path to proeprties file was null or empty");
}
Properties props = null;
try(InputStream resourceStream = DatabaseUtilities.class.getResourceAsStream("/vimba.properties")) {
if(resourceStream != null){
props = new Properties();
props.load(resourceStream);
return props;
}else{
throw new IllegalArgumentException("In invalid properties file path was provided");
}
} catch (IOException e) {
throw e;
}
}
So why would one approach work and potentially not the other? I am completely out of alternative options so really hope someone can save the day
Thanks

I have just tested something similar on my local machine using your code. It seems to work fine from what I can see.
The only other issue I can see is - if you check the JAR (you can de-compile it), make sure the image you are trying to retrieve is in there and that the filename matches.

Is it possible to copy database file to SD card?

I have a database on my Android phone, and I need to get the information onto an SD card.
Is it possible to save the database file onto the SD card in a readable state? I haven't been able to find any information on how to do this.
Some source code that copies the database file to an SD card would be ideal.

The database file is just like any other file, if you make a binary file copy it will work.
Java has no built in file copy method, so you can use this:
Standard concise way to copy a file in Java?
Just don't forget to add your manifest permission to write to the SD card:
Permission to write to the SD card

Here's a script I've bastardized from several other users on SO. It looks like you can tell android where to store the file, but when you go into the phone with adb shell you might have a hard time finding it!
This code (which I mapped to a temporary button in my action bar for debugging) would print something like: "database saved to: /storage/emulated/0/DB-DEBUG/todotable.db", but going into the shell on my phone I actually found my database at: "/storage/emulated/legacy/DB-DEBUG/"... not sure what's up with that, but now I can check out my database with an sqlite browser!
//db will reside in: /storage/emulated/legacy/DB_DEBUG
private void copyDatabase(Context c, String DATABASE_NAME) {
String databasePath = c.getDatabasePath(DATABASE_NAME).getPath();
File f = new File(databasePath);
OutputStream myOutput = null;
InputStream myInput = null;
Log.d("testing", " testing db path " + databasePath);
Log.d("testing", " testing db exist " + f.exists());
if (f.exists()) {
try {
File directory = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/DB-DEBUG");
if (!directory.exists()){
directory.mkdir();
}
String copyPath = directory.getAbsolutePath() + "/" + DATABASE_NAME;
myOutput = new FileOutputStream(copyPath);
myInput = new FileInputStream(databasePath);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
Toast.makeText(getBaseContext(), "Your database copied to: " + copyPath, Toast.LENGTH_LONG).show();
Log.d("testing", " database saved to: " + copyPath);
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_LONG).show();
} finally {
try {
if (myOutput != null) {
myOutput.close();
myOutput = null;
}
if (myInput != null) {
myInput.close();
myInput = null;
}
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
}