No output to file using PrintWriter

Question

I get no compiling errors, but my code does not output anything to the saved files. The code does create the files, but they're empty. Does anybody see what I did wrong?

public class CellAutomataTest {
  public static void main(String[] args)
  {
    int rule = 120;//Integer.parseInt(args[0]);
    int numGen = 5;//Integer.parseInt(args[1]);
    String fileStem = "ca";//args[2];
    int width = 400;//Integer.parseInt(args[3]);
    int height = 400;//Integer.parseInt(args[4]);

    CellAutomata test = new CellAutomata(numGen, rule);

    PrintWriter writer = null;
    try {
        writer = new PrintWriter(new FileWriter(fileStem + ".js"));
    } catch (IOException ex) {
        Logger.getLogger(CellAutomataTest.class.getName()).log(Level.SEVERE, null, ex);
    }
    PrintWriter writer2 = null;
    try {
        writer2 = new PrintWriter(new FileWriter(fileStem + ".html"));
    } catch (IOException ex) {
        Logger.getLogger(CellAutomataTest.class.getName()).log(Level.SEVERE, null, ex);
    }

    writer.println("function draw() {");
    writer.println("var canvas = document.getElementById('CellAutomata');");
    writer.println("if (canvas && canvas.getContext) {");
    writer.println("var context = canvas.getContext('2d');");

    test.simulate(writer, width, height);

    writer2.println("<html>");
    writer2.println("<head>");
    writer2.println("<script src=\"" + fileStem + ".js></script>");
    writer2.println("<style type=\"text/css\">");
    writer2.println("canvas { border: 1px solid black; }");
    writer2.println("</style> </head>");
    writer2.println("<body onload=\"draw();\">");
    writer2.println("<h1>Cellular Automata with Rule " + rule + "</h1>");
    writer2.println("<canvas id=\"CellAutomata\" width=\"" + width + "\" height=\"" + height + "\">");
    writer2.println("<p>Your browser doesn't support canvas.</p>");
    writer2.println("</canvas> </body> </html>");
  }
}

user684934 · Accepted Answer · 2012-10-22 01:13:09Z

8

You need to use:

writer2.flush();
writer2.close();

to actually save the file.

answered Oct 22, 2012 at 1:13

user684934

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2 Comments

Jagger Over a year ago

In fact what he needs is to only close the file. Closing does flush what has been written to the output stream.

The Rationalist Over a year ago

Thank you. I'm new to Java, so I did not know I had to include that. I should've known there was some command to do so. Anyways, now I'm saving to the file successfully, and have discovered that it's not creating the grid as suspected, so now the fun really begins.

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