Java.io.File.exists() timeout?
Hi. I have some shortcuts on a java app that point to network shares using paths of the type \\servername\share
Since those shares are in different servers, sometimes one or two are not available and I wanted to have that reflect in the application before the user clicks on them so I've coded it so that the JButton's that point there will an X icon if the share is not available or else, it will have the standard folder icon.
The code is something like this:
String endereco = "\\servername\share";
java.io.File f = new java.io.File(endereco);
botao.setIcon(menu.icon_verifying);
if(!f.exists()) {
botao.setIcon(menu.icon_error);
} else {
botao.setIcon(icon_success);
}My problem is that f.exists() takes too long if the share is not available. The way it knows that its not available seems to be to wait for a timeout but the timeout is too long for a regular local area network.
I can imagine I could do that on another thread and then use a timer to abort it or something but is there a simpler way?
Thanks.
your problem is not related to the File class. The File class relies heavily on the local filesystem without knowing that there is some sort of network behind it, so if the local filesystem takes a long time to respond, so will the File class.
The threading option is a good workaround for your problem. At least it keeps your application responsive.
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String strPicUrl = "/images/thefile.jpg"; //Actual value comes from database
File theFile = new File(application.getRealPath(strPicUrl));
out.print("File Exists: " + theFile.exists() + "<br>");the actual file name in this example is "/images/theFile.jpg", and theFile.exists() always returns true if the file is there, but differs in case. If I try to display the image it doesnt show up under Tomcat because aliasing is turned off by default. I need to find a way to determine if a file exists based on actual case matching. This way if I get a "true" value, the file should be accessible and/or viewable via the JSP engine.
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String theDir = "C:\\Dir\\Subdir\\";
FileFilter theFilter = new FileFilter() {
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public boolean accept(File file)
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if (fileName.endsWith(_theFile)) return true;
return false;
public void setTheFile(String theFileParam)
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[javac] ...blah error stuff...
[javac] cannot resolve symbol
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Since I am invoking the FileFilter object directly and not instantiating it in a class, is that causing the error or am I declaring "setTheFile()" wrong? -
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Dialog prompt and check if file exists, and use the result of dialog
I have this working script and I want to change the way it behaves.
I want a dialog to come up, Do you want to skip or replace existing files.
Then the result of the dialog to be used in the reast of the script.
I've added it in the script where I need to use it. in noce big letters, hopefully its not a big job.
Many thanks
property type_list : {"8BPS"}
property extension_list : {"psd"}
script o
property theseNames : {}
end script
-- empty log file
do shell script "echo 'Files not processed in Photoshop :' > ~/Desktop/LogPhotoshopError.txt"
set noError to true
--Setup list of folders and process details of folders
set dtF to paragraphs of (do shell script "ls -F ~/Desktop | grep '/' | cut -d'/' -f1")
set tc to (count dtF)
repeat with i from 1 to tc
set folderName to item i of dtF --<: is the folder name, no need to use text item delimiters -->":"
if folderName does not start with "2_" and folderName does not start with "Hot" and folderName does not start with "Press" and folderName does not start with "Design" and folderName does not start with "Keywords" and folderName does not start with "Season" and folderName does not start with "Sue" and folderName does not start with "Design" then
set {oldTID, my text item delimiters} to {my text item delimiters, "_WK"}
set FolderEndName to last text item of folderName
set brandName to first text item of folderName
set my text item delimiters to "_PSD"
set weekNumber to first text item of FolderEndName
set my text item delimiters to oldTID
set theFolder to ("Hal 9000:Users:matthew:Desktop:" & folderName)
--set up names to destination folders and create locally based on brand name and week number
set this_local_folder to "Images:2012-2013"
set localWeekFolder to my getFolderPath("WK" & weekNumber, this_local_folder)
set localBrandFolder to my getFolderPath(brandName, localWeekFolder)
set localBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", localBrandFolder)
set localBrandFolder_High_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_HR", localBrandFolder)
set localBrandFolder_PSD to my getFolderPath(brandName & "_WK" & weekNumber & "_PSD", localBrandFolder)
set this_Network_folder to "GEN:Brands:Zoom:Brand - Zoom:Upload Photos:2013:"
set networkWeekFolder to my getFolderPath("Week" & weekNumber, this_Network_folder)
set networkBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", networkWeekFolder)
set website_images to "GEN:Website_Images:"
--set up names to destination folders and create over Netwrok for FTP collection (based on a mounted drive)
set this_ftp_folder to "pulse:"
set ftpWeekFolder to my getFolderPath("Week" & weekNumber, this_ftp_folder)
set ftpBrandFolder to my getFolderPath(brandName, ftpWeekFolder)
set ftpBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", ftpBrandFolder)
set ftpBrandFolder_High_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_HR", ftpBrandFolder)
--at the beginning of the script, ask whether to replace or skip existing files? to apply to all?
--use the result for the if file exists?
display dialog "Should I replace or skip exisiting files?" buttons {"Replace", "Skip (Faster)"} default button 2 with icon 1
--taking the folder identify which process it must follow.
if brandName is equal to "BH" then
try
tell application "Finder" to set o's theseNames to (name of files of alias theFolder whose file type is in the type_list or name extension is in the extension_list)
on error
set o's theseNames to {} -- no psd files or "8BPS"
end try
set numOfNames to (count o's theseNames)
repeat with j from 1 to numOfNames
set thefile to theFolder & ":" & (item j of o's theseNames)
-- B H Folder Photoshop Process
--if thefile exists in the folder localBrandFolder_PSD then do the result of dialog.
--"Skip" the file and move on to next
--If "replace" continue the rest of the script.
tell application "Adobe Photoshop CS5.1"
-- I remove the command activate, Photoshop stay in background
set ruler units of settings to pixel units
try
open (alias thefile) showing dialogs never
set origName to name of current document
set myOptions to {class:JPEG save options, quality:12}
set myPSDOptions to {class:Photoshop save options, embed color profile:true, save layers:true}
tell current document
--If the quick mask mode has been left on then delete the channel Quick Mask
if (quick mask mode) then delete channel ¬
"Quick Mask"
--If the Layer is incorrectly labeled with Original Layer it needs renaming to original Image
if (exists layer "Original Layer") then ¬
tell layer "Original Layer" to set name to "Original Image"
save in (localBrandFolder_PSD & origName) as Photoshop format with options myPSDOptions without copying
(delete layer "Original Image") flatten
resize image resolution 300 resample method none
--sharpen image
filter current layer using unsharp mask with options {amount:80, radius:3.2, threshold:0}
save in (localBrandFolder_High_Res & name) as JPEG with options myOptions without copying
--get file path, return path of the JPEG file, work with (without copying)
-- (with copying) : it return path of PSD file
set newFile to file path --( return path of type alias )
-- duplicate file using the Finder -->on duplicateFile(..)
my duplicateFile(newFile, {ftpBrandFolder_High_Res})
--Prepare for Low RES by resetting image history
set current history state to history state 3
flatten
resize image width 1348
resize image resolution 300 resample method none
filter current layer using unsharp mask with options {amount:80, radius:3.2, threshold:0}
--add save to lowResFolder with same options
save in (localBrandFolder_Low_Res & name) as JPEG with options myOptions without copying
set newFile to file path
set newFile2 to newFile as string -- for testing end of name
if newFile2 ends with "_2.jpg" or newFile2 ends with "_3.jpg" then -- exclude website_images
my duplicateFile(newFile, {networkBrandFolder_Low_Res, ftpBrandFolder_Low_Res})
else
my duplicateFile(newFile, {networkBrandFolder_Low_Res, ftpBrandFolder_Low_Res, website_images})
end if
close saving no
end tell
on error
set noError to false
my myLogs(thefile) -- write path to log file in Desktop
try
close saving no --if exists, close current document
end try
end try
end tell
end repeat
--End BH
-- else if and the rest of the script.....
end repeat
if not noError then do shell script "/usr/bin/open ~/Desktop/LogPhotoshopError.txt'"
on myLogs(t)
try
do shell script "echo " & (quoted form of t) & ">> ~/Desktop/LogPhotoshopError.txt'"
end try
end myLogs
on duplicateFile(tFile, foldersPath) -- tFile is an alias, foldersPath is a list of folder
tell application "Finder" to repeat with folderPath in foldersPath
with timeout of 200 seconds -- adjust it, error if the copy is longer that 200 seconds
duplicate tFile to folder folderPath with replacing
end timeout
end repeat
end duplicateFile
on getFolderPath(tName, folderPath)
tell application "Finder" to tell folder folderPath
if not (exists folder tName) then
return (make new folder at it with properties {name:tName}) as string
else
return (folder tName) as string
end if
end tell
end getFolderPath
tell application "Finder"
open "Hal 9000:Users:matthew:Desktop:LogPhotoshopError.txt"
end tellHi,
I think that's what you want.
I put the dialog in the beginning, so it does not appear to each folder, otherwise put it in the loop as it was originally.
property type_list : {"8BPS"}
property extension_list : {"psd"}
script o
property theseNames : {}
end script
-- empty log file
do shell script "echo 'Files not processed in Photoshop :' > ~/Desktop/LogPhotoshopError.txt"
set noError to true
--at the beginning of the script, ask whether to replace or skip existing files? to apply to all?
--use the result for the if file exists?
display dialog "Should I replace or skip exisiting files?" buttons {"Replace", "Skip (Faster)"} default button 2 with icon 1
set skipFiles to (button returned of the result) is "Skip (Faster)"
--Setup list of folders and process details of folders
set dtF to paragraphs of (do shell script "ls -F ~/Desktop | grep '/' | cut -d'/' -f1")
set tc to (count dtF)
repeat with i from 1 to tc
set folderName to item i of dtF --<: is the folder name, no need to use text item delimiters -->":"
if folderName does not start with "2_" and folderName does not start with "Hot" and folderName does not start with "Press" and folderName does not start with "Design" and folderName does not start with "Keywords" and folderName does not start with "Season" and folderName does not start with "Sue" and folderName does not start with "Design" then
set {oldTID, my text item delimiters} to {my text item delimiters, "_WK"}
set FolderEndName to last text item of folderName
set brandName to first text item of folderName
set my text item delimiters to "_PSD"
set weekNumber to first text item of FolderEndName
set my text item delimiters to oldTID
set theFolder to ("Hal 9000:Users:matthew:Desktop:" & folderName)
--set up names to destination folders and create locally based on brand name and week number
set this_local_folder to "Images:2012-2013"
set localWeekFolder to my getFolderPath("WK" & weekNumber, this_local_folder)
set localBrandFolder to my getFolderPath(brandName, localWeekFolder)
set localBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", localBrandFolder)
set localBrandFolder_High_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_HR", localBrandFolder)
set localBrandFolder_PSD to my getFolderPath(brandName & "_WK" & weekNumber & "_PSD", localBrandFolder)
set this_Network_folder to "GEN:Brands:Zoom:Brand - Zoom:Upload Photos:2013:"
set networkWeekFolder to my getFolderPath("Week" & weekNumber, this_Network_folder)
set networkBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", networkWeekFolder)
set website_images to "GEN:Website_Images:"
--set up names to destination folders and create over Netwrok for FTP collection (based on a mounted drive)
set this_ftp_folder to "pulse:"
set ftpWeekFolder to my getFolderPath("Week" & weekNumber, this_ftp_folder)
set ftpBrandFolder to my getFolderPath(brandName, ftpWeekFolder)
set ftpBrandFolder_Low_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_LR", ftpBrandFolder)
set ftpBrandFolder_High_Res to my getFolderPath(brandName & "_WK" & weekNumber & "_HR", ftpBrandFolder)
--taking the folder identify which process it must follow.
if brandName is equal to "BH" then
try
tell application "Finder" to set o's theseNames to (name of files of alias theFolder whose file type is in the type_list or name extension is in the extension_list)
on error
set o's theseNames to {} -- no psd files or "8BPS"
end try
set numOfNames to (count o's theseNames)
repeat with j from 1 to numOfNames
set thefile to theFolder & ":" & (item j of o's theseNames)
-- B H Folder Photoshop Process
tell application "Finder" to set b to exists file (localBrandFolder_PSD & item j of o's theseNames)
if b and not skipFiles then -- file exists and "replace" (continue the rest of the script).
tell application "Adobe Photoshop CS5.1"
-- I remove the command activate, Photoshop stay in background
set ruler units of settings to pixel units
try
open (alias thefile) showing dialogs never
set origName to name of current document
set myOptions to {class:JPEG save options, quality:12}
set myPSDOptions to {class:Photoshop save options, embed color profile:true, save layers:true}
tell current document
--If the quick mask mode has been left on then delete the channel Quick Mask
if (quick mask mode) then delete channel ¬
"Quick Mask"
--If the Layer is incorrectly labeled with Original Layer it needs renaming to original Image
if (exists layer "Original Layer") then ¬
tell layer "Original Layer" to set name to "Original Image"
save in (localBrandFolder_PSD & origName) as Photoshop format with options myPSDOptions without copying
(delete layer "Original Image") flatten
resize image resolution 300 resample method none
--sharpen image
filter current layer using unsharp mask with options {amount:80, radius:3.2, threshold:0}
save in (localBrandFolder_High_Res & name) as JPEG with options myOptions without copying
--get file path, return path of the JPEG file, work with (without copying)
-- (with copying) : it return path of PSD file
set newFile to file path --( return path of type alias )
-- duplicate file using the Finder -->on duplicateFile(..)
my duplicateFile(newFile, {ftpBrandFolder_High_Res})
--Prepare for Low RES by resetting image history
set current history state to history state 3
flatten
resize image width 1348
resize image resolution 300 resample method none
filter current layer using unsharp mask with options {amount:80, radius:3.2, threshold:0}
--add save to lowResFolder with same options
save in (localBrandFolder_Low_Res & name) as JPEG with options myOptions without copying
set newFile to file path
set newFile2 to newFile as string -- for testing end of name
if newFile2 ends with "_2.jpg" or newFile2 ends with "_3.jpg" then -- exclude website_images
my duplicateFile(newFile, {networkBrandFolder_Low_Res, ftpBrandFolder_Low_Res})
else
my duplicateFile(newFile, {networkBrandFolder_Low_Res, ftpBrandFolder_Low_Res, website_images})
end if
close saving no
end tell
on error
set noError to false
my myLogs(thefile) -- write path to log file in Desktop
try
close saving no --if exists, close current document
end try
end try
end tell
end if -- else "Skip" the file and move on to next
end repeat
--End BH
end if
end if
end repeat
if not noError then do shell script "/usr/bin/open ~/Desktop/LogPhotoshopError.txt'"
on myLogs(t)
try
do shell script "echo " & (quoted form of t) & ">> ~/Desktop/LogPhotoshopError.txt'"
end try
end myLogs
on duplicateFile(tFile, foldersPath) -- tFile is an alias, foldersPath is a list of folder
tell application "Finder" to repeat with folderPath in foldersPath
with timeout of 200 seconds -- adjust it, error if the copy is longer that 200 seconds
duplicate tFile to folder folderPath with replacing
end timeout
end repeat
end duplicateFile
on getFolderPath(tName, folderPath)
tell application "Finder" to tell folder folderPath
if not (exists folder tName) then
return (make new folder at it with properties {name:tName}) as string
else
return (folder tName) as string
end if
end tell
end getFolderPath
tell application "Finder"
open "Hal 9000:Users:matthew:Desktop:LogPhotoshopError.txt"
end tell -
UNC paths and java.io.file in Oracle
Hi,
I'm just getting to grips with using some basic java in the database. I'm using 8.1.7 on W2K.
I'm trying to test for the existance of a file on a separate w2k domain:
import java.io.File;
public class JFileExists {
public static int fileexists (String fileName) {
File myFile = new File (fileName);
boolean retval = myFile.exists();
if (retval) return 1; else return 0;
public static void main (String args[]) {
System.out.println (
fileexists (args[0])
grant javasyspriv to mp;
function jfn_file_exists (file_in IN VARCHAR2) RETURN number
AS LANGUAGE JAVA NAME 'JFileExists.fileexists (java.lang.String) return int';
From the command prompt all is well:
E:\java>"c:\oracle\ora81\Apache\jdk\bin\java.exe" JFileExists i:\test.txt
1
E:\java>"c:\oracle\ora81\Apache\jdk\bin\java.exe" JFileExists \\mpweb1\image\test.txt
1
But when loaded into oracle its returning false with the UNC path. (but is ok with a mapped drive to the same path)
SQL> declare
2 begin
3 pa_main.pr_print(to_char(pa_main.jfn_file_exists('I:\test.txt')));
4 pa_main.pr_print(to_char(pa_main.jfn_file_exists('\\mpweb1\image\test.txt')));
5 end;
6 /
1
0
PL/SQL procedure successfully completed.
The oracleservicesid and listener are starting under a user called oracle_user which is a member
of the admins and domain admins group.
mpweb1 is on a separate domain to the database server mpdb1 but it also has a user called oracle_user with the same password.
oracle_user has full access to the share in question.
Am I missing something? I was trying to keep the database server and web server on different domains for better security
- but would things be easier if they were on the same domain?
Any help much appreciated for this java newbi!
Thanks,
Simon.
nullI am also having problems with UNC paths. But I cannot access the location even if it is mapped as a drive. In JDK VJM I do not have a problem, but in Oracle it says the file cannot be found and say permission denied. I will try to change the user that starts the database and see if that helps.
null -
File.exists() returs false even the file is present in the specified path
Hi,
When i try to run the following program which checks whether the file exists in the given path or not
public class FileCheck {
public static void main(String[] a){
String str = a[0];
File f = new File(str);
if(f.exists())
System.out.println("File Exists ");
else
System.out.println("File does not Exists ");
So on solaris 10(korean) we have file named in korean language under "usr" directory. When i try to run the above program on solaris 10(Korean) using the default jre (1.5)with the parameter "/usr/file name in korean language" .The output of the program is "File Exists"
And when i run the same class file using the jre (1.6) which is installed in our application which is an english version with the same parameter ""/usr/file name in korean language"
The output of the program is "File does not exists".
And this problem is only with the files which contain the name in korean language.
So do we need to set any properties for the jre in our application to work for files which are named in korean language. Any help will be highly appreciated.
Thanks,
GPK
Edited by: gpk_04 on Nov 11, 2008 1:46 PM
Edited by: gpk_04 on Nov 11, 2008 1:57 PMMy guess is that Java 5 and 6 are picking up the file system encoding differently. As a consequence, the JVM is either:
1. reading and converting your command line argument incorrectly, or
2. reading and converting the file name from the file system incorrectly.
Write a quicky, short app that prints out the file encoding of your host. Run this under 5 and then 6. Do you see different outputs? -
Trying to write data to a text file using java.io.File
I am trying to create a text file and write data to it by using java.io.File and . I am using JDeveloper 10.1.3.2.0. When I try run the program I get a java.lang.NullPointerException error. Here is the snippet of code that I believe is calling the class that's causing the problem:
String fpath = "/test.html";
FileOutputStream out = new FileOutputStream(fpath);
PrintStream pout = new PrintStream(out);
Do I need to add additional locations for source files or am I doing something wrong? Any suggestions would be appreciated.
Thank you.Hi dhartle,
May be that can help:
* Class assuming handling logs and connections to the Oracle database
* @author Fabre tristan
* @version 1.0 03/12/07
public class Log {
private String fileName;
* Constructor for the log
public Log(String name) {
fileName = name;
* Write a new line into a log from the line passed as parameter and the system date
* @param line The line to write into the log
public void lineWriter(String line) {
try {
FileWriter f = new FileWriter(fileName, true);
BufferedWriter bf = new BufferedWriter(f);
Calendar c = Calendar.getInstance();
Date now = c.getTime();
String dateLog =
DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM,
Locale.FRANCE).format(now);
bf.write("[" + dateLog + "] :" + line);
bf.newLine();
bf.close();
} catch (IOException e) {
System.out.println(e.getMessage());
* Write a new line into a log from the line passed as parameter,
* an header and the system date
* @param header The header to write into the log
* @param info The line to write into the log
public void lineWriter(String header, String info) {
lineWriter(header + " > " + info);
* Write a new long number as line into a log from the line
* passed as parameter, an header and the system date
* @param header The header to write into the log
* @param info The line to write into the log
public void lineWriter(String header, Long info) {
lineWriter(header + " > " + info);
* Enable to create folders needed to correspond with the path proposed
* @param location The path into which writing the log
* @param name The name for the new log
* @return Log Return a new log corresponding to the proposed location
public static Log myLogCreation(String location, String name) {
boolean exists = (new File(location)).exists();
if (!exists) {
(new File(location)).mkdirs();
Log myLog = new Log(location + name);
return myLog;
* Enable to create the connection to the DB
* @return Connection Return a new connection to the Oracle database
public static Connection oracleConnectionCreation() throws Exception {
// Register the Oracle JDBC driver
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
//connecting to the DB
Connection conn =
DriverManager.getConnection("jdbc:oracle:thin:@myComputerIP:1521:myDB","user", "password");
return conn;
* This main is used for testing purposes
public static void main(String[] args) {
Log myLog =
Log.myLogCreation("c:/Migration Logs/", "Test_LinksToMethod.log");
String directory = "E:\\Blob\\Enalapril_LC-MS%MS_MS%MS_Solid Phase Extraction_Plasma_Enalaprilat_ERROR_BLOB_test";
myLog.lineWriter(directory);
System.out.println(directory);
[pre]
This class contained some other functions i've deleted, but i think it still works.
That enables to create a log (.txt file) that you can fill line by line.
Each line start by the current system date. This class was used in swing application, but could work in a web app.
Regards,
Tif -
Java.io.File and uppercase/lowercase
Hello,
I am running into a weird problem with java.io.File on a Windows system. My program needs to validate a path the user entered. Sometimes, the path will contain a directory name that should be uppercase, but which the user entered in lowercase instead, and the <File>.exists() returns true anyways. I know on Windows, on the command line, directory and file names are not case-sensitive, which is probably why it was done that way. But this is causing problems because once the path is (supposedly) validated, it is handed to a Unix program (case-sensitive), and if it's not really valid there, the user has no way of correcting it. Whereas if it were found as invalid in the Java program, I could pop up an error, and the user could correct it.
The bottom line is, is there a way of telling a File object to return false if the path name is not EXACTLY identical, on Windows? Or would I have to check the path myself, without relying on File?
Thanks in advance,
J-SIn this case, this is not acceptable, since the files or directories on disk can be in any case. I just need the entered case to be exactly the same as the files.
In other terms, I need File.exists() to return false if the case does not match. I would think there is a way to do this, since internally, the function checks if the operating system is Windows or Unix before doing the comparison, and acts differently in each case...
From http://java.sun.com/j2se/1.3/docs/api/java/io/File.html (see equals or compareTo method) :
"On UNIX systems, alphabetic case is significant in comparing pathnames; on Win32 systems it is not."
I would like to force the Unix way of doing. -
File size (using java.io.File)
Hello all,
When I want to create an app to be used as file browser, I should like to know the size of a file in a directory. The java.io.File class gives me quite some functionality, but not the functionality to display the file size.
Does anyone know of a default class that has the functionality to display the file size?
When no such class exists, I should need to develop it myself. From the top of my head it should be something like this:
int size = 0;
int aChar = 0;
FileReader reader = new FileReader (theFile);
while (reader.ready() )
aChar = reader.read()
size++;
}The variable size gives me now the number of characters in a file. But this should be done for each file in a particular directory. But does that not ask much CPU performance? Does anyone have an alternative?
Looking forward to your answer
MichelHi, I'm having the exact same problem, except that I'm doing a fax system so I can't copy a file while the file is still open. So to check to see if the file is open I have to check the file size in bytes then wait a second and check the file size again. If the file sizes differ then I have to check the next file otherwise I can copy the file. I had a look at the length() method but that will only return the actual length of the file name, not the size of the contents of the file which I need, can anyone please help? Say the file name is 16 ad an a or anything to the file name, if you the call the length() method again it will return 17.
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Hi all,
I have been trying to transfer the file from one server to another using java code. Using the api in the java.IO and the code from the following site http://www.roseindia.net/java/example/java/io/CopyDirectory.shtml
First i shared the folder to be transfered, then at the receiving end, i map the network drive.. Using the code as in the site, i can transfer the file over.
But i found that if the connection break in the mapping of the network drive, the code cannot resume the file transfer from where it left behind.
Actually, my requiremnts is to able to transfer the file and able to resume from where it stop when the connection break and not to overwrite any files.. and it able to check the sending server if there is any new files added to the folder, if yes then it will transfer over the receiving server.
Thanks
chengUsing ... the code from the following site http://www.roseindia.net/java/example/java/io/CopyDirectory.shtml
That was your first mistake. That site is a notorious source of complete rubbish. In this case, unusually, the code looks not too bad apart from not calling mkdirs() as well as mkdir().
But i found that if the connection break in the mapping of the network drive, the code cannot resume the file transfer from where it left behind.Correct. It doesn't do that. So you need to modify it to do so. If it finds that the target file exists and has a non-zero length, it needs to open it for append and skip to that offset in the source file before starting the copy loop. If it finds that the target file exists and has the same length as the source file and the same date it can skip the file completely. That should cover both your requirements. -
Java.io.File renameTo does not work on Solaris
Hi Experts,
I have a code-piece which tries to move files from one directory to another on the SAME FILE SYSTEM using java.io.File.renameTo method.
It works fine when there less no. of files in the source directory. But the renameTo does not work as expected when there are very huge no. of files(~40K) present in the source directory.
I am aware that there is a known issue when one tries to use this method to move files across file systems OR if the file exists at the destination directory.
But in my case the file system is the same and the there is no such file in the destination directory.
I suspect some inode related issues. But not sure what it is exactly.
Is there any limitations of renameTo?
Please help.OK, we all now understand you have a problem in doing this, but without the specifics of the problem that you are experiencing, then it is fairly difficult to give you anything other than a guess. If you would like some specific and relevent answers, please supply specifics about how exactly the operation differs from your expected results. You should also post example code as it is almost always asked for eventually.
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Hi,
While I'm doing this course I'm trying to do more programs, in order to learn more about RPI, and I have a problem. I'm trying to acces to some files with threads, one to read the file and another one to read the file. The problem I get is when I just try to import java.io.file, it doesn't exist! so I cannot manage Files at all.
I've seen there no such a class in the javame8 directory, so I've try to copy the class by psftp, but it doesn't work, either.
Do you know why I can't to import the java.io.file and work with files?
thank you very muchHi -
First, Java ME is a subset of Java SE. Many of the standard packages are simply not available in Java ME. java.io.File is one of many classes that is not available in Java ME.
I encourage you to read through the API for Java ME's core API's, here.
And while java.io.File is not supported, Java ME Embedded 8 does support file I/O using an optional package, JSR-75. We will cover this in next week's lesson.
Tom -
File.exists() takes too long to return.
Hi.
I have written a program which checks to see if a particular shared file is present on a number of different computers. The path to the file is the same on all the computers.
I construct the File with IP + path.
Then I call file.exists()
If the remote computer is on and the file is present, then 'true' is returned quite quickly. But if the file is not available then 'false' is returned but only after about 30 seconds. This is too long and I want to set some sort of time out for the method after about 3 seconds. So that if the file is not found before the timeOut time, 'false' will be returned.
Is there any way I can do this???
Thanks,
JimHi,
I am already using Threads, here is my code:
public class FileExistsThread extends Thread {
private File file;
private long tryTime;
private boolean exists;
private boolean changed;
public FileExistsThread(File file, long tryTime) {
this.file = file;
this.tryTime = tryTime;
public void run() {
new Thread() {
public void run() {
try {
Thread.sleep(tryTime);
} catch(Exception e) {}
exists = false;
changed = true;
}.start();
exists = file.exists();
changed = true;
public boolean fileExists() {
start();
while(!changed);
return exists;
}The Problem is that I cant close my program while a file.exists() method is still executing no matter what Thread it is in. Say I'm looking for a file which the program will take 30 seconds to establish is not available. Then for that 30 seconds my program will refuse to close. Sometimes it can be much longer than this.
This is why I still need some sort of timeout mechanism.
Any Ideas?
Cheers,
Jim -
Hi experts, I have an issue "java.io.File".
File f = new File( this.myFM.myGlobal.AgreementsDirectory + "/" + ClientDocBean.getSubdirectory() + "/" + ClientDocBean.getFilename());
// Check that the file exists, if not then throw an error
if(!f.exists()) {
this.myFM.myErrorHandler.ERRORLIST.add("Unable to find file: " + f.getPath() );
this.missingDocument();
return;
}The following is used to get documents from our main NAS system and works perfectly on the development system. However on the live system this fails to find the file.
When I run the path (used in f.getPath()) in windows (run) it opens the file perfectly on the live server.
The Setup
On the development system the files are pulled from the NAS system inhouse (Mounted drive) however on the web server this is connected using a VPN mounted to the same path as the development server. I think this might be related to server lag as this live system has to talk over the Internet VPN to get the file.
does anyone have any ideas how to solve this issue? does "java.io.File" have a tool to wait or should I be using some other method of getting the files content.
Ta in advance..
giz
PS I can't copy the file to the public domain and link to it as there is a lot of security requirments. No file can exist on the public path, even for a second.To elaborate a little more.
The main issue is that a mounted drive links to a network folder. This drive was not available to Tomcat. This means that when the Servlet tries to access the file it can not be found.
Using the Network path I was able to locate the file however Tomcat did not have permission to read this file.
The next step was to create a user under [Active Directory|http://www.visualwin.com/New-User-AD/] called tomcat. I assigned read permissions to the folder (That Tomcat tried to read).
The next step was to get Tomcat to run as this user. This will allow all my Servlets to access the give folder. It also means that Tomcat cannot read other files on the network as they do not have permission as the OS level. This means that any security holes in the code can not be expoilted (Without flaging my IDS).
I am running Tomcat in a windows envroment so changing the user it's running as is very easy.
# open the Tomcat config app
# Click "Logon" tab
# Check "This Account"
# Under the new user account and password setup using Active Directory
# Click "Apply" then "Ok"
# Restart tomcat
After this Tomcat should be running as your new user and have access to the given folder and files
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