I am using java.nio.file package and tried to create file with the following code.
private static void printReport(String filename, String str)throws Exception{
ErrorCheck ec = new ErrorCheck();
String fileName = "/var/Emails_log/"+filename;
Path filePath = Paths.get(fileName);
File file = new File(fileName);
final BufferedWriter out = Files.newBufferedWriter(filePath, StandardCharsets.UTF_8, StandardOpenOption.APPEND);
try{
final Path tmp = filePath.getParent();
if (tmp != null){ // null will be returned if the path has no parent
Files.createDirectories(tmp);
} else {
out.write(str);
out.write('n');
}
} catch(Exception e) {
ec.errorMsg("ERROR: GSW.SendEmail.Exception =>",e);
} finally {
if (out != null) {
out.flush();
out.close();
}
}
}
This throws following Exception:
java.nio.file.NoSuchFileException: /var/Emails_log/GSWvalidSentAddresses.txt at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107) at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214) at java.nio.file.spi.FileSystemProvider.newOutputStream(FileSystemProvider.java:430) at java.nio.file.Files.newOutputStream(Files.java:170) at java.nio.file.Files.newBufferedWriter(Files.java:2720) at SendEmail.printReport(SendEmail.java:114) SendEmail.send(SendEmail.java:87)
My question is why file is not created?
Please advise
Thanks in anticipation
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Answer
Updated Answer:
Now that you’ve shown the full code, there are two major problems:
You’re trying to open the file before ensuring that the directories leading up to it exist, and
You’re using
StandardOpenOption.APPEND, but that won’t create a file; it will append to an existing file.
…along with a large number of issues around best practices relative to the number of lines of actual code.
See comments:
private static void printReport(String filename, String str) throws Exception /* No, it doesn't. The only calls you had outside your catch-all `try` don't throw exceptions. */ {
ErrorCheck ec = new ErrorCheck(); // Recommend not creating this until/unless you need it
String fileName = "/var/Emails_log/"+filename; // VERY poor practice having two locals that only differ by the capitalization of one character in the middle (`filename` and `fileName`)
Path filePath = Paths.get(fileName);
// File file = new File(fileName); <== Removed, since you never use it for anything
try {
// Make sure the directories exist
Files.createDirectories(filePath.getParent()); // No need for your null check, so I removed it; based on `fileName`, it will always have a parent
// Open the file, creating it if it doesn't exist
try (
final BufferedWriter out = Files.newBufferedWriter(
filePath,
StandardCharsets.UTF_8,
StandardOpenOption.CREATE,
StandardOpenOption.APPEND)
) {
// Write to out here
}
} catch (Exception e) {
// Log-and-continue isn't generally best practice; and if you're going to do it
ec.errorMsg("ERROR: GSW.SendEmail.Exception =>",e); // <== Um...send mail failed? This isn't sending mail, it's putting something in a file.
}
// Using the try-with-resources, we don't have to worry about the flush and close calls
}
But here’s how I would suggest you write it:
private static void printReport(String filename, String str) throws IOException {
Path filePath = Paths.get("/var/Emails_log/" + filename);
// Make sure the directories exist
Files.createDirectories(filePath.getParent());
// Open the file, creating it if it doesn't exist
try (
final BufferedWriter out = Files.newBufferedWriter(
filePath,
StandardCharsets.UTF_8,
StandardOpenOption.CREATE,
StandardOpenOption.APPEND)
) {
// Write to out here, perhaps outputting `str`?
}
}
…and handle exceptions in the calling layer. Note that, again, because we’re using try-with-resources, the close is automatic (both when there’s an exception and when there isn’t).
Or if you really want to do log-and-continue:
private static void printReport(String filename, String str) {
try {
Path filePath = Paths.get("/var/Emails_log/" + filename);
// Make sure the directories exist
Files.createDirectories(filePath.getParent());
// Open the file, creating it if it doesn't exist
try (
final BufferedWriter out = Files.newBufferedWriter(
filePath,
StandardCharsets.UTF_8,
StandardOpenOption.CREATE,
StandardOpenOption.APPEND)
) {
// Write to out here, perhaps outputting `str`?
}
}
catch (Exception e) {
new ErrorCheck().errorMsg("ERROR: GSW.SendEmail.Exception =>", e); // <== But surely this message is suspect? I don't see anything sending email here.
}
}
Original Answer:
You haven’t shown the code that’s actually failing, which is a call to newBufferedWriter (this one, or this one). newBufferedWriter takes OpenOptions, the standard set of which are available from StandardOpenOption. Make sure you’ve specified StandardOpenOption.CREATE or StandardOpenOption.CREATE_NEW,
If you use one of those flags, and the code in your question isbefore the newBufferedWriter call, barring some other problem (permissions) it should work:
String fileName = "/var/Emails_log/"+filename;
Path filePath = Paths.get(fileName);
final Path tmp = filePath.getParent();
if (tmp != null) { // <== Note: There's no point to this check, given
// your filename above, the path WILL have a parent.
// You could remove the `if` and just use
// `Files.createDirectories(tmp)` unless the `fileName`
// is actually coming from somewhere else and so could
// be a root (roots don't have parents)
Files.createDirectories(tmp);
}
else {
out.write(str); // I assume this is for logging or display?
out.write('n'); // Specifically, that it's *not* trying to write
// to the file you're trying to create.
}
try (BufferedWriter writer = Files.newBufferedWriter(filePath, StandardOpenOption.CREATE)) {
// ------------------------------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^
// Write to the file here
}