Simple debugger class

[Barry Andrews]

Hello All,
I want to write a simple debugger class that I can call to write debugging information to a file. I am getting some weird results from this code. Here is an example of something I am tried to send to a file:

Debug d = new Debug();
               d.write("compare:");
               d.write("currentBandRed[" + bandIndex + "] = " + currentBandRed[bandIndex] +
                                  " oRed[" + bandIndex + "] = " + oRed[bandIndex]);
               d.write("currentBandGreen[" + bandIndex + "] = " + currentBandGreen[bandIndex] +
                                  " oGreen[" + bandIndex + "] = " + oGreen[bandIndex]);
               d.write("currentBandBlue[" + bandIndex + "] = " + currentBandBlue[bandIndex] +
                                  " oBlue[" + bandIndex + "] = " + oBlue[bandIndex]);
               d.close();

I am only getting the last line in the debug.txt file. The other 3 lines above it do not get written. Does anyone know what I am doing wrong? Many thanks!
Barry

import java.io.*;

     public class Debug
     {
        private PrintWriter pw;
        public Debug()
        {
        }//end constructor
       public void write(String output)
       {
          try
          {
             pw = new PrintWriter(new FileWriter("debug.txt",true),true);//append mode and auto flush
             pw.print(output);
             pw.println();
             }
          catch(IOException io)
          {
             io.printStackTrace();
             }
          }//end write() method
       public void close()
       {
         if (pw!=null)
          {
             pw.close();
             pw = null;
          }
          }//end close() method

       }//end Debug class

[Lewin Chan]

It's because you're creating a new printwriter in the debug class every time you invoke write(). It may be, that even if you auto-flush, the file isn't really synced to disk, until the printwriter is closed;
I would change your class so that the the printwriter is created during the constructor
public Debug()
{
pw = new PrintWriter(new FileWriter("fred.txt", true),true);
}