Java/File Input Output/Print To Files

illustrates using a PrintWriter to handle console output

 
import java.io.PrintWriter;
public class PrintWriterDemo {
  public static void main(String args[]) {
    PrintWriter pw = new PrintWriter(System.out, true);
    pw.println("This is a string");
    int i = -7;
    pw.println(i);
    double d = 4.5e-7;
    pw.println(d);
  }
}

Printing an HTML Table

import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.DecimalFormat;
public class HTMLDemo {
  public static void main(String[] a) throws IOException {
    PrintWriter pw = new PrintWriter(new FileWriter("test.html"));
    DecimalFormat ff = new DecimalFormat("#0"), cf = new DecimalFormat(
        "0.0");
    pw.println("<TABLE BORDER><TR><TH>Fahrenheit<TH>Celsius</TR>");
    for (double f = 100; f <= 400; f += 10) {
      double c = 5 * (f - 32) / 9;
      pw.println("<TR ALIGN=RIGHT><TD>" + ff.format(f) + "<TD>"
          + cf.format(c));
    }
    pw.println("</TABLE>");
    pw.close(); // Without this, the output file may be empty
  }
}

Printing Numbers to a Text File

import java.io.FileWriter;
import java.io.PrintWriter;
public class PrintWriterDemo {
  public static void main() throws Exception{
    PrintWriter pw = new PrintWriter(new FileWriter("dice.txt"));
    for (int i = 1; i <= 1000; i++) {
      int die = (int) (1 + 6 * Math.random());
      pw.print(die);
      pw.print(" ");
      if (i % 20 == 0)
        pw.println();
    }
    pw.println();
    pw.close(); // Without this, the output file may be empty
  }
}