Develop Reference

How to save an PNG via code in a Runnable JAR file?

I'm having trouble fixing this issue,
I have created a Client\Server side application and created a Method where a user can
"Send" a PNG file from his side to Server side, then the Server side "Creates" and saves the image in a Package that only contains pictures.
When i run this Method of sending a Picture from Client side to Server side via Eclipse IDE
it works as expected, but when exporting Client/Server side into Runnable JAR files, i get the next error:
Java
private static void getImg(MyFile msg) {
int fileSize =msg.getSize();
System.out.println("length "+ fileSize);
try {
File newFile = new File(System.getProperty("user.dir")+"\\src\\GuiServerScreens\\"+msg.getFileName());
FileOutputStream fileOut;
fileOut = new FileOutputStream(newFile);
BufferedOutputStream bufferOut = new BufferedOutputStream(fileOut);
try {
bufferOut.write(msg.getMybytearray(), 0, msg.getSize());
fileOut.flush();
bufferOut.flush();
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
I get the follow error :
java.io.FileNotFoundException: java.io.FileNotFoundException: C:\Users\Ilya\Desktop\src\GuiServerScreens\test.png (The system cannot
find the path specified)
It seems that using File newFile = new File(System.getProperty("user.dir")+"\\src\\GuiServerScreens\\"+msg.getFileName());
Does not provide the wanted result

I think you are mixing what your directories look like in netbeans with what's available on the server. Save to an external directory instead, not to your src directory.

Java Zip File Extraction

I have a GTFS schedule manager which automatically downloads a zipped file from a specified provider URL and extracts files from it on the fly to a specified folder. So at the end of this process the folder contains just the extracted files and not the zipped file itself.
This has up to now always worked worked but with
http://mta.maryland.gov/_googletransit/latest/google_transit.zip
it does not work for some reason. When I go to get the first zip entry from the stream it is null. I can however manually download the zipped file to a local folder, change the URL in my java application to it and it extracts fine. It is just the extraction on the fly that does not work.
This is demonstrated by running the code below as it is: you will see the failure. If you then download the zipped file manually to the "feeds" folder and swap around the commented "extractFilesFromFeed.extract" lines in main below the extraction works.
Question is if there a change I can make below so that this particular URL can be extracted on the fly ?
===
import java.io.File;
import java.io.FileOutputStream;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class ExtractFilesFromFeed {
private Logger logger = Logger.getLogger("");
public void extract(String feedLocation, String feedFolder) throws Exception {
if (feedLocation == null || feedLocation.length() == 0) {
String tmp = "Invalid feed location specified for GTFS schedule file extraction";
throw new Exception(tmp);
}
else if (feedFolder == null || feedFolder.length() == 0) {
String tmp = "Invalid feed folder specified for GTFS schedule file extraction";
throw new Exception(tmp);
}
else {
logger.log(Level.INFO, String.format("Extracting GTFS schedule files from %s to %s",
feedLocation, feedFolder));
}
URL url;
if (feedLocation.startsWith("http")) {
url = new URL(feedLocation);
}
else {
url = new File(feedLocation).toURI().toURL();
}
File dir = new File(feedFolder);
if(!dir.exists()){
dir.mkdir();
}
byte[] buffer = new byte[8192];
ZipInputStream zis = new ZipInputStream(url.openStream());
ZipEntry ze = zis.getNextEntry();
if (ze == null) {
logger.log(Level.WARNING, "Unable to get first entry from zip file, aborting download");
zis.close();
throw new Exception(String.format("Unable to get first entry from zip file %s", feedLocation));
}
while (ze != null){
String zipFileName = ze.getName();
if (ze.isDirectory()) {
dir = new File(feedFolder + "/" + zipFileName);
if(!dir.exists()){
dir.mkdir();
}
}
else {
FileOutputStream fos = new FileOutputStream(feedFolder + File.separator + zipFileName);
int len;
while ((len = zis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
fos.close();
}
ze = zis.getNextEntry();
}
zis.close();
}
public static void main(String[] args) throws Exception {
ExtractFilesFromFeed extractFilesFromFeed = new ExtractFilesFromFeed();
extractFilesFromFeed.extract("http://mta.maryland.gov/_googletransit/latest/google_transit.zip", "feeds");
//extractFilesFromFeed.extract("feeds/google_transit.zip", "feeds");
}
}

Looks like there are actually two problems here:
http://mta.maryland.gov/_googletransit/latest/google_transit.zip has a HTTP 301 redirect to a secure SSL version at https://mta.maryland.gov/_googletransit/latest/google_transit.zip.
The SSL handshake may fail due to lack of security policy files
For the redirect, you'll need to use something like the following:
URL url;
if (feedLocation.startsWith("http")) {
url = new URL(feedLocation);
URLConnection urlConnection = url.openConnection();
// Check for HTTP 301 redirect
String redirect = urlConnection.getHeaderField("Location");
if (redirect != null) {
logger.log(Level.WARNING, "Redirecting to " + redirect);
url = new URL(redirect);
}
} else {...
Then, when opening the input stream, you'll probably want to catch and log any SSLHandshakeExceptions:
try {
ZipInputStream zis = new ZipInputStream(url.openStream());
...
} catch (SSLHandshakeException sslEx) {
logger.log(Level.ERROR, "SSL handshake failed. Try installing the JCE Extension - see http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html");
}
To install the JCE Extension, you will need to replace the US_export_policy.jar and local_policy.jar files in your JVM /security directory, such as C:\Program Files\Java\jdk1.8.0_73\jre\lib\security, with the JAR files in the JCE Extension download.
I just fixed this same issue in our project - the commit that resolved the issue is https://github.com/CUTR-at-USF/gtfs-realtime-validator/commit/180785d22ca58afa2463b322ad4e1b122c5f0a30, and the Github issue for the problem was https://github.com/CUTR-at-USF/gtfs-realtime-validator/issues/89.
Credit to 301 Moved Permanently for the HTTP 301 redirect solution and https://stackoverflow.com/a/30760134/937715 for installing the JCE Extension.

Android unzip not a directory issue

I am trying to unzip a zip file which is stored in the raw folder. Code is as follows
try
{
File myDir = new File(getFilesDir().getAbsolutePath());
File newFile = new File(myDir + "/imageFolder");
if(!newFile.exists())
{
newFile.mkdir();
}
ZipInputStream zipIs = new ZipInputStream(con
.getResources().openRawResource(R.raw.images));
ZipEntry ze = null;
while ((ze = zipIs.getNextEntry()) != null)
{
Log.v("Name", ze.getName());
Log.v("Size", "" + ze.getSize());
if(ze.getSize() >0)
{
FileOutputStream fout = new FileOutputStream(newFile
+ "/" + ze.getName());
byte[] buffer = new byte[1024];
int length = 0;
while ((length = zipIs.read(buffer)) > 0)
{
fout.write(buffer, 0, length);
}
zipIs.closeEntry();
fout.close();
}
}
zipIs.close();
} catch (Exception e)
{
e.printStackTrace();
}
But I keep getting this error
01-18 11:24:28.301: W/System.err(2285): java.io.FileNotFoundException:
/data/data/com.example.ziptests/files/imageFolder/TestImages/background.png
(Not a directory)
I have absolutely no idea why it is causing this, it finds the files, but when it comes to writing them out, it brings up that error. Originally I found a problem that was caused by having the zip file zipped up on the mac, so I zipped up the file on my windows machine instead, that got rid of one problem (when you zip on a mac, it adds these extra folders and files such s store.ds which causes an error when trying to unzip), but this not a directory error keeps coming up.
Any ideas why this is happening?

Please try below link code for unzip zip file.
Code for Extract Zip File
Unzip Zip File
The Problem is I am Uploading zip File which is not made using winrar software, so it is not proper extracted and give me error.
It will solve your problem.

You can't write files to the raw folder. It is a read only dir intended to contain resource files included in your apk.
UPDATE
That file would be better in the assets directory. You can access it through the AssetManager. If not, leave it in the res/raw dir, but access it through Resources.openRawResource. Either way they are Read-Only.

zip the files which are present at one FTP location and copy to another FTP location directly

I want to create zip file of files which are present at one ftp location and Copy this zip file to other ftp location without saving locally.
I am able to handle this for small size of files.It works well for small size files 1 mb etc
But if file size is big like 100 MB, 200 MB , 300 MB then its giving error as,
java.io.FileNotFoundException: STOR myfile.zip : 550 The process cannot access the
file because it is being used by another process.
at sun.net.ftp.FtpClient.readReply(FtpClient.java:251)
at sun.net.ftp.FtpClient.issueCommand(FtpClient.java:208)
at sun.net.ftp.FtpClient.openDataConnection(FtpClient.java:398)
at sun.net.ftp.FtpClient.put(FtpClient.java:609)
My code is
URLConnection urlConnection=null;
ZipOutputStream zipOutputStream=null;
InputStream inputStream = null;
byte[] buf;
int ByteRead,ByteWritten=0;
***Destination where file will be zipped***
URL url = new URL("ftp://" + ftpuser+ ":" + ftppass + "#"+ ftppass + "/" +
fileNameToStore + ";type=i");
urlConnection=url.openConnection();
OutputStream outputStream = urlConnection.getOutputStream();
zipOutputStream = new ZipOutputStream(outputStream);
buf = new byte[size];
for (int i=0; i<li.size(); i++)
{
try
{
***Souce from where file will be read***
URL u= new URL((String)li.get(i)); // this li has values http://xyz.com/folder
/myPDF.pdf
URLConnection uCon = u.openConnection();
inputStream = uCon.getInputStream();
zipOutputStream.putNextEntry(new ZipEntry((String)li.get(i).substring((int)li.get(i).lastIndexOf("/")+1).trim()));
while ((ByteRead = inputStream .read(buf)) != -1)
{
zipOutputStream.write(buf, 0, ByteRead);
ByteWritten += ByteRead;
}
zipOutputStream.closeEntry();
}
catch(Exception e)
{
e.printStackTrace();
}
}
if (inputStream != null) {
try {
inputStream .close();
}
catch (Exception e) {
e.printStackTrace();
}
}
if (zipOutputStream != null) {
try {
zipOutputStream.close();
} catch (Exception e){
e.printStackTrace();
}
}
Can anybody let me know how I can avoid this error and handle large files

This is unrelated to file sizes; as the error says, you can't replace the file because some other process is currently locking it.
The reason why you see it more often with large files is because these take longer to transfer hence the chance of concurrent accesses is higher.
So the only solution is to make sure that no one uses the file when you try to transfer it. Good luck with that.
Possible other solutions:
Don't use Windows on the server.
Transfer the file under a temporary name and rename it when it's complete. That way, other processes won't see incomplete files. Always a good thing.
Use rsync instead of inventing the wheel again.

Back in the day, before we had network security, there were FTP servers that allowed 3rd party transfers. You could use site specific commands and send a file to another FTP server directly. Those days are long gone. Sigh.
Ok, maybe not long gone. Some FTP servers support the proxy command. There is a discussion here: http://www.math.iitb.ac.in/resources/manuals/Unix_Unleashed/Vol_1/ch27.htm

How to copy a file on the FTP server to a directory on the same server in Java?

I'm using Apache Commons FTP to upload a file. Before uploading I want to check if the file already exists on the server and make a backup from it to a backup directory on the same server.
Does anyone know how to copy a file from a FTP server to a backup directory on the same server?
public static void uploadWithCommonsFTP(File fileToBeUpload){
FTPClient f = new FTPClient();
FTPFile backupDirectory;
try {
f.connect(server.getServer());
f.login(server.getUsername(), server.getPassword());
FTPFile[] directories = f.listDirectories();
FTPFile[] files = f.listFiles();
for(FTPFile file:directories){
if (!file.getName().equalsIgnoreCase("backup")) {
backupDirectory=file;
} else {
f.makeDirectory("backup");
}
}
for(FTPFile file: files){
if(file.getName().equals(fileToBeUpload.getName())){
//copy file to backupDirectory
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
Edited code: still there is a problem, when i backup zip file, the backup-ed file is corrupted.
Does any body know the reason for it?
public static void backupUploadWithCommonsFTP(File fileToBeUpload) {
FTPClient f = new FTPClient();
boolean backupDirectoryExist = false;
boolean fileToBeUploadExist = false;
FTPFile backupDirectory = null;
try {
f.connect(server.getServer());
f.login(server.getUsername(), server.getPassword());
FTPFile[] directories = f.listDirectories();
// Check for existence of backup directory
for (FTPFile file : directories) {
String filename = file.getName();
if (file.isDirectory() && filename.equalsIgnoreCase("backup")) {
backupDirectory = file;
backupDirectoryExist = true;
break;
}
}
if (!backupDirectoryExist) {
f.makeDirectory("backup");
}
// Check if file already exist on the server
f.changeWorkingDirectory("files");
FTPFile[] files = f.listFiles();
f.changeWorkingDirectory("backup");
String filePathToBeBackup="/home/user/backup/";
String prefix;
String suffix;
String fileNameToBeBackup;
FTPFile fileReadyForBackup = null;
f.setFileType(FTP.BINARY_FILE_TYPE);
f.setFileTransferMode(FTP.BINARY_FILE_TYPE);
for (FTPFile file : files) {
if (file.isFile() && file.getName().equals(fileToBeUpload.getName())) {
prefix = FilenameUtils.getBaseName(file.getName());
suffix = ".".concat(FilenameUtils.getExtension(file.getName()));
fileNameToBeBackup = prefix.concat(Calendar.getInstance().getTime().toString().concat(suffix));
filePathToBeBackup = filePathToBeBackup.concat(fileNameToBeBackup);
fileReadyForBackup = file;
fileToBeUploadExist = true;
break;
}
}
// If file already exist on the server create a backup from it otherwise just upload the file.
if(fileToBeUploadExist){
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
f.retrieveFile(fileReadyForBackup.getName(), outputStream);
InputStream is = new ByteArrayInputStream(outputStream.toByteArray());
if(f.storeUniqueFile(filePathToBeBackup, is)){
JOptionPane.showMessageDialog(null, "Backup succeeded.");
f.changeWorkingDirectory("files");
boolean reply = f.storeFile(fileToBeUpload.getName(), new FileInputStream(fileToBeUpload));
if(reply){
JOptionPane.showMessageDialog(null,"Upload succeeded.");
}else{
JOptionPane.showMessageDialog(null,"Upload failed after backup.");
}
}else{
JOptionPane.showMessageDialog(null,"Backup failed.");
}
}else{
f.changeWorkingDirectory("files");
f.setFileType(FTP.BINARY_FILE_TYPE);
f.enterLocalPassiveMode();
InputStream inputStream = new FileInputStream(fileToBeUpload);
ByteArrayInputStream in = new ByteArrayInputStream(FileUtils.readFileToByteArray(fileToBeUpload));
boolean reply = f.storeFile(fileToBeUpload.getName(), in);
System.out.println("Reply code for storing file to server: " + reply);
if(!f.completePendingCommand()) {
f.logout();
f.disconnect();
System.err.println("File transfer failed.");
System.exit(1);
}
if(reply){
JOptionPane.showMessageDialog(null,"File uploaded successfully without making backup." +
"\nReason: There wasn't any previous version of this file.");
}else{
JOptionPane.showMessageDialog(null,"Upload failed.");
}
}
//Logout and disconnect from server
in.close();
f.logout();
f.disconnect();
} catch (IOException e) {
e.printStackTrace();
}
}

If you are using apache commons net FTPClient, there is a direct method to move a file from one location to another location (if the user has proper permissions).
ftpClient.rename(from, to);
or, If you are familiar with ftp commands, you can use something like
ftpClient.sendCommand(FTPCommand.yourCommand, args);
if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
//command successful;
} else {
//check for reply code, and take appropriate action.
}
If you are using any other client, go through the documentation, There wont be much changes between client implementations.
UPDATE:
Above approach moves the file to to directory, i.e, the file won't be there in from directory anymore. Basically ftp protocol meant to be transfer the files from local <-> remote or remote <-> other remote but not to transfer with in the server.
The work around here, would be simpler, get the complete file to a local InputStream and write it back to the server as a new file in the back up directory.
to get the complete file,
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
ftpClient.retrieveFile(fileName, outputStream);
InputStream is = new ByteArrayInputStream(outputStream.toByteArray());
now, store this stream to backup directory. First we need to change working directory to backup directory.
// assuming backup directory is with in current working directory
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);//binary files
ftpClient.changeWorkingDirectory("backup");
//this overwrites the existing file
ftpClient.storeFile(fileName, is);
//if you don't want to overwrite it use storeUniqueFile
Hope this helps you..

Try this way,
I am using apache's library .
ftpClient.rename(from, to) will make it easier, i have mentioned in the code below
where to add ftpClient.rename(from,to).
public void goforIt(){
FTPClient con = null;
try
{
con = new FTPClient();
con.connect("www.ujudgeit.net");
if (con.login("ujud3", "Stevejobs27!!!!"))
{
con.enterLocalPassiveMode(); // important!
con.setFileType(FTP.BINARY_FILE_TYPE);
String data = "/sdcard/prerakm4a.m4a";
ByteArrayInputStream(data.getBytes());
FileInputStream in = new FileInputStream(new File(data));
boolean result = con.storeFile("/Ads/prerakm4a.m4a", in);
in.close();
if (result)
{
Log.v("upload result", "succeeded");
//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$Add the backup Here$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$//
// Now here you can store the file into a backup location
// Use ftpClient.rename(from, to) to place it in backup
//$$$$$$$$$$$$$$$$$$$$$$$$$$$$$Add the backup Here$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$//
}
con.logout();
con.disconnect();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}

There's no standard way to duplicate a remote file over FTP protocol. Some FTP servers support proprietary or non-standard extensions for this though.
So if your are lucky that your server is ProFTPD with mod_copy module, you can use FTP.sendCommand to issue these two commands:
f.sendCommand("CPFR sourcepath");
f.sendCommand("CPTO targetpath");
The second possibility is that your server allows you to execute arbitrary shell commands. This is even less common. If your server supports this you can use SITE EXEC command:
SITE EXEC cp -p sourcepath targetpath
Another workaround is to open a second connection to the FTP server and make the server upload the file to itself by piping a passive mode data connection to an active mode data connection. Implementation of this solution (in PHP though) is shown in FTP copy a file to another place in same FTP.
If neither of this works, all you can do is to download the file to a local temporary location and re-upload it back to the target location. This is that the answer by #RP- shows.
See also FTP copy a file to another place in same FTP.

To backup at same Server (move), can you use:
String source="/home/user/some";
String goal ="/home/user/someOther";
FTPFile[] filesFTP = cliente.listFiles(source);
clientFTP.changeWorkingDirectory(goal); // IMPORTANT change to final directory
for (FTPFile f : archivosFTP)
{
if(f.isFile())
{
cliente.rename(source+"/"+f.getName(), f.getName());
}
}