CODEWITHSUNDEEP
javatime-format
GeekySelene
GeekySelene

Reputation: 927

java SimpleDateFormat returns a part of the time on windows

I am trying to get the current time and append it to the name of a file that I generate.

the code snippet: 

DateTimeFormatter dtf = DateTimeFormatter.ofPattern(app.values.getProperty("yyyy-MM-dd"));
LocalDateTime now = LocalDateTime.now();
String date = dtf.format(now);
Date today = Calendar.getInstance().getTime();
SimpleDateFormat timeFormat = new SimpleDateFormat("hh:mm");
String time = timeFormat.format(today);
FileOutputStream fs = new FileOutputStream("receipt/Receipt_" + date + "_"+time+".pdf");

This works fine on linux (returns "Receipt_2018-04-18_11:13" for the name of the file) but when I run the jar on windows 7, it only gives 

Receipt_2018-04-18_11

and the generated file is damaged and empty. How can I fix this?

Upvotes: 0

Views: 794

Answers (3)

MadProgrammer
MadProgrammer

Reputation: 347204

SimpleDateFormat timeFormat = new SimpleDateFormat("hh:mm");
String time = timeFormat.format(today);
FileOutputStream fs = new FileOutputStream("receipt/Receipt_" + date + "_"+time+".pdf");

: is an illegal file character (under Windows at least, probably others).

For more information, have a look at Naming Files, Paths, and Namespaces, it contains a list of invalid file/directory name characters

Maybe change it to -, for example

SimpleDateFormat timeFormat = new SimpleDateFormat("hh-mm");
String time = timeFormat.format(today);
FileOutputStream fs = new FileOutputStream("receipt/Receipt_" + date + "_"+time+".pdf");

or use SimpleDateFormat timeFormat = new SimpleDateFormat("hhmm"); instead

Update

So apparently fixing the immediate issue isn't enough for some people.

The java.util.Date classes are generally considered deprecated and you should instead make use of the newer (and improved) java.time API instead, for example...

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd_hh-mm");
FileOutputStream fs = new FileOutputStream("receipt/Receipt_" + formatter.format(LocalDateTime.now()) + ".pdf");

Or, if you can't (use Java 8+), one of the many available libraries, including the back port for java.time

Upvotes: 1

user326260
user326260

Reputation: 45

Try this i think it will work with you

For java.util.Date, just create a new Date()

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");    Date date = new Date();     System.out.println(dateFormat.format(date));

Upvotes: -1

Sergey Prokofiev
Sergey Prokofiev

Reputation: 1885

The issue is that ':' is incorrect character for the filenames on Windows OS, thus it needs to be replaced. Basically your code is excessive, you don't need Calendar since LocalDateTime already has timestamp part.

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd_hh_mm");
LocalDateTime now = LocalDateTime.now();
String dateTime = dtf.format(now);
FileOutputStream fs = new FileOutputStream("receipt/Receipt_" + dateTime + ".pdf");

Hope it helps!

Upvotes: 3

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