Java Tutorial/Development/Formatter

Formatter.ioException()

import java.io.FileOutputStream;
import java.util.Formatter;
public class Main {
  public static void main(String[] argv) throws Exception {
    Formatter fmtCon = new Formatter(System.out);
    Formatter fmtFile;
    fmtFile = new Formatter(new FileOutputStream("test.fmt"));
    fmtCon.format("a negative number: %(.2f\n\n", -123.34);
    fmtCon.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtCon.format("%8d %8d\n", i, i * i);
    // write to the file.
    fmtFile.format("This is a negative number: %(.2f\n\n", -123.34);
    fmtFile.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtFile.format("%8d %8d\n", i, i * i);
    fmtFile.close();
    if (fmtFile.ioException() != null) {
      System.out.println("File I/O Error Occurred");
    }
  }
}

locale-specific formatting.

import java.util.Calendar;
import java.util.Formatter;
import java.util.Locale;
public class Main {
  public static void main(String args[]) {
    Formatter fmt = new Formatter();
    Calendar cal = Calendar.getInstance();
    fmt = new Formatter();
    fmt.format("Default locale: %tc\n", cal);
    fmt.format(Locale.GERMAN, "For Locale.GERMAN: %tc\n", cal);
    fmt.format(Locale.ITALY, "For Locale.ITALY: %tc\n", cal);
    fmt.format(Locale.FRANCE, "For Locale.FRANCE: %tc\n", cal);
    System.out.println(fmt);
  }
}

new Formatter(new OutputStream("test.fmt"))

import java.io.FileOutputStream;
import java.util.Formatter;
public class Main {
  public static void main(String[] argv) throws Exception {
    Formatter fmtCon = new Formatter(System.out);
    Formatter fmtFile;
    fmtFile = new Formatter(new FileOutputStream("test.fmt"));
    fmtCon.format("a negative number: %(.2f\n\n", -123.34);
    fmtCon.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtCon.format("%8d %8d\n", i, i * i);
    // write to the file.
    fmtFile.format("This is a negative number: %(.2f\n\n", -123.34);
    fmtFile.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtFile.format("%8d %8d\n", i, i * i);
    fmtFile.close();
    if (fmtFile.ioException() != null) {
      System.out.println("File I/O Error Occurred");
    }
  }
}

Write formatted output directly to the console and to a file.

import java.io.FileOutputStream;
import java.util.Formatter;
public class Main {
  public static void main(String[] argv) throws Exception {
    Formatter fmtCon = new Formatter(System.out);
    Formatter fmtFile;
    fmtFile = new Formatter(new FileOutputStream("test.fmt"));
    fmtCon.format("a negative number: %(.2f\n\n", -123.34);
    fmtCon.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtCon.format("%8d %8d\n", i, i * i);
    // write to the file.
    fmtFile.format("This is a negative number: %(.2f\n\n", -123.34);
    fmtFile.format("%8s %8s\n", "Value", "Square");
    for (int i = 1; i < 20; i++)
      fmtFile.format("%8d %8d\n", i, i * i);
    fmtFile.close();
    if (fmtFile.ioException() != null) {
      System.out.println("File I/O Error Occurred");
    }
  }
}