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Index › Programming Questions & Help › Syntax Questions › try/catch... how it work to check if a file exist
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try/catch... how it work to check if a file exist? (Read 2048 times)
FelTheCat
try/catch... how it work to check if a file exist?
Nov 25th, 2007, 11:05pm  
I'm trying to check if a file exist before loading it and I have no idea how to do this. I'm trying with try/cacth. Am I near of the solution? :

for(int i = 0; i < nombreImages; i++) {
   try {
          loadedLines = loadStrings("dataFrame" + i + ".txt");
   }
   catch (Exception e){ // NullPointerException don't work either
          fileExist = false;
          println("exist" + e);
   }
   if (fileExist){
   ...
   }
}
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« Last Edit: Nov 26th, 2007, 5:10am by FelTheCat »  
 
mark hill
Re: try/catch... how it work to check if a file ex
Reply #1 - Nov 26th, 2007, 9:50am  
this ought to work (untested) for testing whether a file exists or not:

boolean fileExists(String filename) {

 File file = new File(filename);

 if(!file.exists())
  return false;
   
 return true;
}


This should help:

http://java.sun.com/j2se/1.4.2/docs/api/java/io/File.html
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fjen
Re: try/catch... how it work to check if a file ex
Reply #2 - Nov 26th, 2007, 10:10am  
dataPath( "filename.ext" );
will give you the path to the sketch's data folder. that is handy in such situations ...

have a look at the openStreamRaw() source. should give you an idea on how to check existance / validity of a file / url.

F
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WWW  
clone45
Re: try/catch... how it work to check if a file ex
Reply #3 - Dec 21st, 2008, 7:52pm  
I ran into the same problem, and fjen's solution worked great.  Here's my code:

Code:


String filename = "foo.txt";

File f = new File(dataPath(filename));

if (f.exists())
{
  // do something
}


If you need to look in a specific subdirectory, try:

Code:


String filename = "foo.txt";

File f = new File(dataPath("/subdirectory/" + filename));

if (f.exists())
{
  // do something
}
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