Hi,

I'm using Processing with Arduino, and I like to do something like create an text file, only if it doesn't exist.

If the file already exist, the Processing have to write in the end of the text file.

This don't seems to be dificult, but I'm newbie on Processing and I have no idea how to do it, I couldn't find anything in the reference...

Someone can help to do that?

Thanks!

But it not works here

Code:

PrintWriter output;
FileWriter file; 

.
.
.

String write_file;
  
  d = day();
  m = month();
  y = year();
  Hr = hour();
  Mn = minute();

  date_time = (String.valueOf(d) + '_' + String.valueOf(m) + '_' + String.valueOf(y) + ".txt");
  folder_name = (String.valueOf(m) + '_' + String.valueOf(y));
  write_file = (String.valueOf(Hr) + ":" + String.valueOf(Mn) + "\n");

  println(write_file); // check

  try  
  {
    file = new FileWriter("c:/logs_ard/" + folder_name + "/" + date_time, true); //bool tells to append

    file.write(write_file, 0, write_file.length()+1); //(string)
    println("wrote");
    file.close();
  }  
  catch(Exception e)  
  {
      println("created");
  } 

This code always return me "created"  

What am I doing wrong?

When the folder doesn't exist, the program create the folder and file but don't write in the file, but when the folder already exist, the program does nothing...

This what I get:

java.lang.StringIndexOutOfBoundsException: String index out of range: 5
     at java.lang.String.getChars(String.java:849)
     at sun.nio.cs.StreamEncoder.write(StreamEncoder.java:115)
     at java.io.OutputStreamWriter.write(OutputStreamWriter.java:203)
     at Rele_RBE.inicia_log(Rele_RBE.java:268)
     at Rele_RBE.setup(Rele_RBE.java:288)
     at processing.core.PApplet.handleDraw(Unknown Source)
     at processing.core.PApplet.run(Unknown Source)
     at java.lang.Thread.run(Thread.java:619)

What is this? I don't know anything about Java, and very little about Processing...