Read Serial Data and save to txt file

dataLogger.pde

import processing.serial.*;

Serial mySerial;
PrintWriter output;
void setup() {
   mySerial = new Serial( this, Serial.list()[1], 9600 );
   println(Serial.list());   
   output = createWriter( "data.txt" );
}
void draw() {
    if (mySerial.available() > 0 ) {
         String value = mySerial.readStringUntil('\n');
         if ( value != null ) {
              output.printf("%d/%d/%d %d:%d:%d ,",year(),month(),day(),hour(),minute(),second());
              output.println( value );
         }
    }
}

void keyPressed() {
    output.flush();  // Writes the remaining data to the file
    output.close();  // Finishes the file
    exit();  // Stops the program
}