Question

i’ve a Java program that print out some text output. Actually my simple PrintOutput function is something like

System.out.println("some output");

But i would like to declare a variable

printonfile = true

to print my output to a text file if setted to true, or to screen (console) if setted to false.

How can i assign the out to a file instead to System.out avoiding to make something like

 if (printonfile) {
   myfile.out("some output");
 }
 else {
   System.out.println("some output");
 }

Is there a way to declare an “output” variable at the beginning of my function so i can assign it the standard output (console) or a text file ?

Thanks

Answer 1

The out field of the System class is an instance of the PrintStream class; you can also construct a PrintStream object that outputs to a file. So your idea of setting up the output location could work as follows

PrintStream myOut = null;
// Decide output method somehow
if(...) {
  myOut = System.out;
}
else {
  myOut = new PrintStream(new File("/path/to/a/file"));
}

// Use the PrintStream to write a message
myOut.println("Hello World");

// Tidy up at end
myOut.close();