code: public static void main(String[] args) {
          try{
              if (args.length < 1 || args.length > 3){
                  System.out.println("Usage:  PdfContentReaderTool <pdf file> [<output file>|stdout] [<page num>]");
                  return;
              }
              
              PrintWriter writer = new PrintWriter(System.out);
              if (args.length >= 2){
                  if (args[1].compareToIgnoreCase("stdout") != 0){
                      System.out.println("Writing PDF content to " + args[1]);
                      writer = new PrintWriter(new FileOutputStream(new File(args[1])));
                  }
              }
  
              int pageNum = -1;
              if (args.length >= 3){
                  pageNum = Integer.parseInt(args[2]);
              }
              
              if (pageNum == -1){
                  listContentStream(new File(args[0]), writer);
              } else {
                  listContentStream(new File(args[0]), pageNum, writer);
              }
              writer.flush();
              
              if (args.length >= 2){
                  writer.close();
                  System.out.println("Finished writing content to " + args[1]);
              }
          } catch (Exception e){
              e.printStackTrace(System.err);
          }
      }
docs: Writes information about each page in a PDF file to the specified file, or System.out.
  @param args