Develop Reference

How do i find a filepath given only the name of the file?

I am currently working on transferring a file from a server to a client via tcp connection. The file exists somewhere within a sharedroot directory of the server. This is the sample code of my upload method for server upload to client.
public void upload(String filename, DataOutputStream out) throws IOException {
File fname = null;
if (filename.contains(sharedroot)) { //this is if the client provides a proper filepath with the filename
fname = new File(filename);
}else { //if client only provides a filename without path
fname = new File(filename);
//"..\\..\\"+ //i was working around with this, but somehow just making the file whether or not it contains the sharedroot seems to give me the "best" output so far...
}
System.out.println(fname.getCanonicalPath());
if (fname.isDirectory()) {
System.out.println("File is a directory");
String quit = "404 not found";
sendOut(quit, out);
return;
}
String path = fname.getAbsolutePath();
System.out.println(path);
if (fname.isFile()) {
String canonpath = fname.getCanonicalPath();
if (canonpath.contains(sharedroot)) {
try {
FileInputStream in = new FileInputStream(fname);
byte[] buffer = new byte[1024];
out.writeInt(fname.getName().length());
out.write(fname.getName().getBytes(), 0, fname.getName().length()); // writes file name only, not
// including the path
long size = fname.length();
out.writeLong(size);
while (size > 0) {
int len = in.read(buffer, 0, buffer.length);
out.write(buffer, 0, len);
size -= len;
}
} catch (Exception e) {
System.out.println("Error occurred in uploading file to client. Please try again");
}
}else {
System.out.println("File not in shared directory");
String quit = "404 not found";
sendOut(quit, out);
}
}else {
System.out.println("File not exists");
String quit = "404 not found";
sendOut(quit, out);
}
}
The output given by getCanonicalPath() and getAbsolutePath() as seen below is wrong because it is checking inside the directory of my eclipse and not the sharedroot directory. How can I get the filepath of the file so that i can compare it to my sharedroot and ensure it exists within the sharedroot? The sharedroot would be for example: D:\seant\2uniFiles\1. FINE2005 Year 3
D:\seant\eclipse-workspace\DCN3005\Lecture 1 Exercise.pdf
D:\seant\eclipse-workspace\DCN3005\Lecture 1 Exercise.pdf
File not exists

Your creation of File does not specify a dedicated directory. There are two constructors requiring a (root) directory and a file name – one as File itself, the other as String. I assume one of your paths is relative but your else-branch creates the file the same way as the full qualified path. You should pass the sharedRoot instead as first parameter and the fileName as second.
File fname = null;
// sharedRoot is more like a constant and startsWith
// avoids reading somewhere else that looks similar
if (filename.startsWith(sharedRoot)) {
fname = new File(filename);
} else {
fname = new File(sharedRoot, filename);
}
In all other cases relative paths are relative to the root directory of the VM process – and I mean process. If for example a user starts this in the user's HOME directory it'll be relative to this. If an operating system task starts the VM it'll be relative to the OS process' root – which might be a Unix cron job or a Windows scheduling thing.
Maybe you introduce a sort of configuration of sharedRoot so you don't need to recompile if this changes in the future.

SFTP Mule Client Java API - User Login Time out Issue

I am working on a Java code to SFTP file to remote from HDFS filesystem. It works fine for smallers file less than 200 MB. For large files I get the following error.
17/08/08 02:44:49 ERROR sftp.SftpClient: Error writing data over SFTP service, error was: Failure
4: Failure
at com.jcraft.jsch.ChannelSftp.throwStatusError(ChannelSftp.java:2289)
at com.jcraft.jsch.ChannelSftp.checkStatus(ChannelSftp.java:1937)
at com.jcraft.jsch.ChannelSftp._put(ChannelSftp.java:541)
at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:439)
at com.jcraft.jsch.ChannelSftp.put(ChannelSftp.java:406)
My code is as follows:
public static void sendFile(String targetDirectory, String sourceFileWithFullPath) throws IOException {
SftpClient client = new SftpClient("karthick");
BufferedInputStream bis = null;
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
FSDataInputStream fsdisPath = null;
String filePath = null;
try {
filePath=sourceFileWithFullPath;
Path inputPath = new Path(filePath);
fsdisPath = fs.open(inputPath);
bis = new BufferedInputStream(fsdisPath);
client.login("karthick","/karthick/id_rsa", null);
client.changeWorkingDirectory(targetDirectory);
client.storeFile(inputPath.getName(), bis);
System.out.println("The actual path is" + client.getAbsolutePath(sourceFileWithFullPath));
}
finally {
if (client != null) {
client.disconnect();
}
if (bis != null) {
bis.close();
}
}
}
I ensured that I have enough disk space, no memory issues and all the required permissions. What could be other possible ways to avoid this issue. I am planning to have this utility to copy 500GB files. I am beginning java and learning the fundamentals now. Any suggestions would be greatly appreciated.
Update: I am receiving this error as well com.jcraft.jsch.JSchException: verify: false . I have added keys wherever necessary. How do I resolve this issue
ERROR sftp.SftpClient: Error during login to karthick#karthick
com.jcraft.jsch.JSchException: verify: false
at com.jcraft.jsch.Session.connect(Session.java:295)
at com.jcraft.jsch.Session.connect(Session.java:150)
at org.mule.transport.sftp.SftpClient.login(SftpClient.java:178)

It looks like one of 4 reasons:
1)Permissions on the folder you're writing to
2)Spaces on the file path (or name).
3)Wrong slash in the file path.
4)Time out issues are happen while reading or writing the huge File..

Open file from network drive

I'm trying to create hyperlinks to open files from network drive G:
This is part of my testing servlet:
#WebServlet(name="fileHandler", urlPatterns={"/fileHandler/*"})
public class FileServlet extends HttpServlet
{
private static final int DEFAULT_BUFFER_SIZE = 10240; // 10KB.
...
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
String requestedFile = request.getPathInfo();
...
File file = new File("G:/test_dir", URLDecoder.decode(requestedFile, "UTF-8")); // cesta se nacita v kazdem doGet
String contentType = getServletContext().getMimeType(file.getName());
response.reset();
response.setBufferSize(DEFAULT_BUFFER_SIZE);
response.setContentType(contentType);
response.setHeader("Content-Length", String.valueOf(file.length()));
response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");
BufferedInputStream input = null;
BufferedOutputStream output = null;
try
{
input = new BufferedInputStream(new FileInputStream(file), DEFAULT_BUFFER_SIZE);
output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);
byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
int length;
while ((length = input.read(buffer)) > 0)
{
output.write(buffer, 0, length);
}
}
finally
{
close(output);
close(input);
}
}
}
My HTML component:
TEST FILE
Network drive is mapped on application server as G:\
Everything is working fine on my localhost application server. I'm able to open file from local drive C: and even from the same network drive G:.
When I start the JSF application on real server, I'm able to open files from local drive only. Not from G: drive.
I've tried to simple JAVA application (to find if java instance has an access to network drive) and it works on both (server and dev.PC):
public class Test
{
static void main(String[] args)
{
String path = "G:/test_dir/test.txt";
File file = new File(path);
System.err.println(file.exists() ? "OK" : "NOK");
}
}
I've tried different URI schemes:
G:/test_dir
G:\\test_dir
And following doesn't work at all:
file://server/g:/test_dir
///server/g:/test_dir
\\\\server\\g\\test_dir ---> in fact, this should work
Where should be a difference between my develop PC and application server?
SOLUTION:
I've found that links to network drive doesn't work in standalone Tomcat, but works in Eclipse + Tomcat, so I have to use complete URI:
Case Eclipse + Tomcat: Path G:/test_dir/test.txt works
Case Standalone Tomcat: Path \\\\server\\g\\test_dir\\test.txt works

If you can debug your server and look at the logs, try this:
String requestedFile = request.getPathInfo();
log.debug('requestedFile='+requestedFile);
String decodedFilename = URLDecoder.decode(requestedFile, "UTF-8");
log.debug('decodedFilename='+decodedFilename);
File dir = new File("G:/test_dir");
log.debug('File g:/test_dir is a dir:'+dir.isDirectory());
File file = new File(dir, decodedFilename);
log.debug('requested file = '+file.getAbsolutePath());
log.debug('file exists = '+file.isFile());
If you do not have a logging framework set up, you can use System.out.println() instead of log.debug(), but that's not recommended for production use.
This won't solve your problem, but you'll be able to see what's going on.

I've found that links to network drive doesn't work in standalone Tomcat, but works in Eclipse + Tomcat, so I have to use complete URI:
Case Eclipse + Tomcat: Path G:/test_dir/test.txt works
Case Standalone Tomcat: Path \\\\server\\g\\test_dir\\test.txt works

How to save and load an image on a Tomcat server [duplicate]

This question already has answers here:
Recommended way to save uploaded files in a servlet application
(2 answers)
Closed 7 years ago.
I'm writing a Java EE application, and I try to get an image from an URL then save it in my resource folder (thru an AJAX request).
My problem is if I don't reboot my server I'm not able to display this image because it isn't loaded on my server.
I'm using Tomcat 7, Spring, Hibernate, Primeface.
Here is my class to save myimage
public class ImageSaver {
final static int SIZE=1024;
public static void fileUrl(String fAddress, String localFileName, String destinationDir) {
OutputStream outStream = null;
URLConnection uCon = null;
InputStream is = null;
try {
URL url = new URL(fAddress);
byte[] buf;
int byteRead;
int byteWritten=0;
outStream = new BufferedOutputStream(new FileOutputStream(destinationDir+"\\"+localFileName));
uCon = url.openConnection();
is = uCon.getInputStream();
buf = new byte[SIZE];
while ((byteRead = is.read(buf)) != -1) {
outStream.write(buf, 0, byteRead);
byteWritten += byteRead;
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
try {
is.close();
outStream.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
public static void fileDownload(String fAddress,String fileName, String destinationDir){
int slashIndex =fAddress.lastIndexOf('/');
int periodIndex =fAddress.lastIndexOf('.');
//String fileName=fAddress.substring(slashIndex + 1);
if (periodIndex >=1 && slashIndex >= 0 && slashIndex < fAddress.length()-1){
}
else{
System.err.println("path or file name.");
}
}
}
and the way I call the function :
ImageSaver.fileDownload("http://www.mywebsite.com/myImage.jpg","myImage.jpg", "C:\\Users\\MyProject\\src\\main\\webapp\\resources\\images");
How can I automatically loaded on my serve my uploaded Image without any reboot ?
Which file allows the configuration of an upload folder ? And how ?

You should not write images retrieved dynamically into your webapp's folder - this opens you up for a whole category of problems. Instead, save them to a folder outside of the appserver's root directory and create a download servlet that will serve these resources.
The danger otherwise is that you'll retrieve some jsp file from external sources, save them to your appserver and on download the appserver will happily execute it server side.
Assume your webapp's directory to be non-writeable to your webapp. This will also ease backup and updates: Imagine you'll need to install an update or migrate to a different server: The application you have on your server will only partially be contained in its *.war file. If there's an explicit resource directory, you can back this up independently (or put it on a network share drive)

Webapp deployed in Glassfish can't write to files

I have the following function inside a Stateless EJB running in Glassfish. All it does is write some data to a file. The first part of the function just creates the path to where the file needs to go. The second part actually writes the file.
private boolean createFile(String companyName, String fileName, byte[] data)
{
logger.log(Level.FINEST, "Creating file: {0} for company {1}", new Object[]{fileName, companyName});
File companyFileDir = new File(LOCAL_FILE_DIR, companyName);
if(companyFileDir.exists() == false)
{
boolean createFileDir = companyFileDir.mkdirs();
if(createFileDir == false)
{
logger.log(Level.WARNING, "Could not create directory to place file in");
return false;
}
}
File newFile = new File(companyFileDir, fileName);
try
{
FileOutputStream fileWriter = new FileOutputStream(newFile);
fileWriter.write(data);
}
catch(IOException e)
{
logger.log(Level.SEVERE,"Could not write file to disk",e);
return false;
}
logger.log(Level.FINEST,"File successfully written to file");
return true;
}
The output I get after this code executes is:
WARNING: Could not create directory to place file in
So obviously Glassfish cant create this directory. I am am assuming this has something to do with permissions. Can anyone give me a direction to go as to what might be wrong here?
I am running this on Glassfish 3.12 on Ubuntu 12

different things:
1) Compare spec: (21.1.2 Programming Restrictions)
An enterprise bean must not use the java.io package to attempt to access files and directories in the file system.
I'm sure GF isn't enforcing this, but you should be aware of that.
2) The code itself is fine. Try chmod +777 on the LOCAL_FILE_DIR to get an idea if it has to do with rights in general ...
Hope that helps ...