Writing to a file in java

Question

I am trying to create and write to a java file using print writer.
I looked at How do I create a file and write to it in Java? I am unable to write to the file. The file is created but with no text Can someone please tell me what I missed?
Thanks

static void createFile() throws FileNotFoundException{
    String filename = "nothign.txt";
    FileOutputStream connection1;
    connection1 = new FileOutputStream( filename );
    PrintWriter printnothing = null;

    printnothing = new PrintWriter(connection1);
    printnothing.printf("/nnewline writesomething/n exo");
    printnothing.println("trying to write something");
}// createFile Method

is there any performance benefit (or any benefit) for initializing the variable as null and then assigning it a `new` object. than doing both in the same line? — DevZer0, Aug 17 '13 at 01:48
incidentally printf line seperators don't work with PrintWriter — H J, Aug 17 '13 at 01:59

score 4 · Accepted Answer · answered Aug 17 '13 at 01:43

4

I believe you need to close your PrintWriter in order to flush the contents to the file. Try adding this to the end of your code:

printnothing.close();

answered Aug 17 '13 at 01:43

Juned Ahsan

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Xabster · Answer 2 · 2013-08-17T01:52:58.620

0

You have to flush.

You can automatically flush if you supply true as second parameter in the constructor.
You can flush manually by calling flush().
You can flush implicitly by closing the stream with .close().

You also need to close the stream so the file is released.

You can do it with explicitly calling .close() when you're done with it.
You can take advantage of Java 7's try-with-resource feature with the following syntax..

Example:

try (PrintWriter printnothing = new PrintWriter(new FileOutputStream("nothign.txt"))) {
     printnothing.printf("stuff"); 
     printnothing.println("stuff");
} catch(IOException e) { 
     e.printStacktrace(); // We don't have to close it here, and neither do have to in a finally block - it's handled for us 
}

edited Aug 17 '13 at 01:52

answered Aug 17 '13 at 01:45

Xabster

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IMO there is far too much information here that is irrelevant to the OP's (stated) requirements. He just wants to know why there is no output. – Stephen C Aug 17 '13 at 01:53
Thanks Xabster, thorough answer – H J Aug 17 '13 at 01:59

score 0 · Answer 3 · answered Aug 17 '13 at 01:45

0

You need to call either printnothig.close() (which is what you should do assuming you won't be using that object to print again) or printnothing.flush()

answered Aug 17 '13 at 01:45

Caleb Brinkman

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He needs to close it. It's a local variable. No-one else can close it. Otherwise there is a resource leak. – user207421 Aug 21 '13 at 01:00
You're correct; I wasn't paying close enough attention, thought it was a class variable. – Caleb Brinkman Aug 23 '13 at 23:08

Writing to a file in java

3 Answers3