Detect that the file exists

Question

Please how to detect that the file exists and don't create a new one each time I run it.

public static void main(String[] args) throws IOException, ClassNotFoundException {
    FileOutputStream fos = new FileOutputStream("file.tmp");
    ObjectOutputStream oos = new ObjectOutputStream(fos);

    oos.writeObject("12345");
    oos.writeObject("Today");

    oos.close();

}

Had you gone through the documentation of `File` class, you would have found : - [`File#exists`](http://docs.oracle.com/javase/7/docs/api/java/io/File.html#exists()) method. — Rohit Jain, Nov 05 '12 at 12:37

score 2 · Accepted Answer · answered Nov 05 '12 at 12:36

2

How about

File f = new File("file.tmp");
if(f.exists()) {
 // do something
}

answered Nov 05 '12 at 12:36

Aleksandr M

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thedayofcondor · Answer 2 · 2012-11-05T12:37:24.523

1

Use File.exits():

File f = new File("file.tmp");// this does not create a file

if (f.exists()) {
    System.out.println("File existed");
} else {
    System.out.println("File not found!");
}

Then you can even use the constructor FileOutputStream(File f, boolean append)

edited Nov 05 '12 at 12:37

answered Nov 05 '12 at 12:35

thedayofcondor

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score 1 · Answer 3 · edited Nov 05 '12 at 12:53

1

I think this is what you need:

public boolean settingsFileExits(final String fileName) {
    File f = new File(fileName);
    return f.exists();
}

edited Nov 05 '12 at 12:53

assylias

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answered Nov 05 '12 at 12:37

KernelPanic

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Why the ternary operator and not just "return f.exists();"? – Roger Lindsjö Nov 05 '12 at 12:42
L0L, you are right! :D I did not see that coming ... Thanks for correction! – KernelPanic Nov 05 '12 at 12:44

score 0 · Answer 4 · answered Nov 05 '12 at 12:36

0

Use File class API:

File.exists

answered Nov 05 '12 at 12:36

Azodious

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score 0 · Answer 5 · answered Nov 05 '12 at 12:38

0

Instead of using FileOutputStream use File class then do

if file.exists()

And

Instead of asking immediately in stack over flow, google it.

answered Nov 05 '12 at 12:38

vels4j

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Detect that the file exists

5 Answers5