Java by API/java.text/DateFormat

DateFormat: format(Date date)

 

import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
/** Trivial class to show use of Date & Calendar objects */
public class Main {
  /** Typical main method ("main program") declaration */
  public static void main(String[] av) {
    Locale l1 = new Locale("en", "US"), l2 = new Locale("es", "ES");
    // Create a Date object for May 5, 1986
    Calendar c = Calendar.getInstance();
    c.set(1986, 04, 05); // May 5, 1986
    Date d1 = c.getTime();
    // Create a Date object for today.
    Date d2 = new Date(); // today
    DateFormat df_us = DateFormat.getDateTimeInstance(DateFormat.MEDIUM,
        DateFormat.MEDIUM, l1), df_sp = DateFormat.getDateTimeInstance(
        DateFormat.MEDIUM, DateFormat.MEDIUM, l2);
    System.out.println("Date d1 for US is " + df_us.format(d1));
    System.out.println("Date d1 for Spain is " + df_sp.format(d1));
    System.out.println("Date d2 is " + df_us.format(d2));
  }
}

DateFormat.FULL

 
/*
 * Output:
Japan: 4/28/06
Korea: Apr 28, 2006
United Kingdom: 28 April 2006
United States: Friday, April 28, 2006
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getDateInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.KOREA);
    System.out.println("Korea: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
    System.out.println("United States: " + df.format(date));
  }
}

DateFormat: getAvailableLocales()

 
/* From http://java.sun.ru/docs/books/tutorial/index.html */
/*
 * Copyright (c) 1995-1998 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for NON-COMMERCIAL purposes and without fee is hereby granted
 * provided that this copyright notice appears in all copies. Please refer to
 * the file "copyright.html" for further important copyright and licensing
 * information.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
 * LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES.
 */
import java.text.SimpleDateFormat;
import java.util.Locale;
public class Main {
  static public void main(String[] args) {
    Locale list[] = SimpleDateFormat.getAvailableLocales();
    for (int i = 0; i < list.length; i++) {
      System.out.println(list[i].toString());
    }
    for (int i = 0; i < list.length; i++) {
      System.out.println(list[i].getDisplayName());
    }
    for (int i = 0; i < list.length; i++) {
      System.out.println(list[i].getDisplayName(Locale.FRANCE));
    }
  }
}

DateFormat: getDateInstance(int style,Locale aLocale)

 
/*
 * Output:
Japan: 4/28/06
Korea: Apr 28, 2006
United Kingdom: 28 April 2006
United States: Friday, April 28, 2006
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getDateInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.KOREA);
    System.out.println("Korea: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
    System.out.println("United States: " + df.format(date));
  }
}

DateFormat: getDateTimeInstance(int dateStyle, int timeStyle)

 
/*
 * Copyright (c) 2000 David Flanagan.  All rights reserved.
 * This code is from the book Java Examples in a Nutshell, 2nd Edition.
 * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
 * You may study, use, and modify it for any non-commercial purpose.
 * You may distribute it non-commercially as long as you retain this notice.
 * For a commercial use license, or to purchase the book (recommended),
 * visit http://www.davidflanagan.ru/javaexamples2.
 */
import java.io.PrintWriter;
import java.text.DateFormat;
import java.text.NumberFormat;
import java.util.Date;
import java.util.Locale;
/**
 * A partial implementation of a hypothetical stock portfolio class. We use it
 * only to demonstrate number and date internationalization.
 */
public class Main {
  EquityPosition[] positions;
  Date lastQuoteTime = new Date();
  public Main(EquityPosition[] positions, Date lastQuoteTime) {
    this.positions = positions;
    this.lastQuoteTime = lastQuoteTime;
  }
  public void print(PrintWriter out) {
    // Obtain NumberFormat and DateFormat objects to format our data.
    NumberFormat number = NumberFormat.getInstance();
    NumberFormat price = NumberFormat.getCurrencyInstance();
    NumberFormat percent = NumberFormat.getPercentInstance();
    DateFormat shortdate = DateFormat.getDateInstance(DateFormat.MEDIUM);
    DateFormat fulldate = DateFormat.getDateTimeInstance(DateFormat.LONG,
        DateFormat.LONG);
    // Print some introductory data.
    out.println("Portfolio value at " + fulldate.format(lastQuoteTime)
        + ":");
    out.println("Symbol\tShares\tPurchased\tAt\t" + "Quote\tChange");
    // Display the table using the format() methods of the Format objects.
    for (int i = 0; i < positions.length; i++) {
      out.print(positions[i].name + "\t");
      out.print(number.format(positions[i].shares) + "\t");
      out.print(shortdate.format(positions[i].purchased) + "\t");
      out.print(price.format(positions[i].bought) + "\t");
      out.print(price.format(positions[i].current) + "\t");
      double change = (positions[i].current - positions[i].bought)
          / positions[i].bought;
      out.println(percent.format(change));
      out.flush();
    }
  }
  static class EquityPosition {
    String name; // Name of the stock.
    int shares; // Number of shares held.
    Date purchased; // When purchased.
    double bought; // Purchase price per share
    double current; // Current price per share
    EquityPosition(String n, int s, Date when, double then, double now) {
      name = n;
      shares = s;
      purchased = when;
      bought = then;
      current = now;
    }
  }
  /**
   * This is a test program that demonstrates the class
   */
  public static void main(String[] args) {
    // This is the portfolio to display. Note we use a deprecated
    // Date() constructor here for convenience. It represents the year
    // offset from 1900, and will cause a warning message when compiling.
    EquityPosition[] positions = new EquityPosition[] {
        new EquityPosition("XXX", 400, new Date(100, 1, 3), 11.90,
            13.00),
        new EquityPosition("YYY", 1100, new Date(100, 2, 2), 71.09,
            27.25),
        new EquityPosition("ZZZ", 6000, new Date(100, 4, 17), 23.37,
            89.12) };
    // Create the portfolio from these positions
    Portfolio portfolio = new Portfolio(positions, new Date());
    // Set the default locale using the language code and country code
    // specified on the command line.
    if (args.length == 2)
      Locale.setDefault(new Locale(args[0], args[1]));
    // Now print the portfolio
    portfolio.print(new PrintWriter(System.out));
  }
}

DateFormat: getTimeInstance(int style,Locale aLocale)

 
/*
 * Output:
Japan: 11:25 AM
United Kingdom: 11:25:31 PDT
Canada: 11:25:31 o"clock AM PDT
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getTimeInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getTimeInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getTimeInstance(DateFormat.FULL, Locale.CANADA);
    System.out.println("Canada: " + df.format(date));
  }
}

DateFormat.LONG

 
/*
 * Output:
Japan: 4/28/06
Korea: Apr 28, 2006
United Kingdom: 28 April 2006
United States: Friday, April 28, 2006
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getDateInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.KOREA);
    System.out.println("Korea: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
    System.out.println("United States: " + df.format(date));
  }
}

DateFormat.MEDIUM

 
/*
 * Output:
Japan: 4/28/06
Korea: Apr 28, 2006
United Kingdom: 28 April 2006
United States: Friday, April 28, 2006
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getDateInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.KOREA);
    System.out.println("Korea: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
    System.out.println("United States: " + df.format(date));
  }
}

DateFormat: parse(String dateString)

 
/*
Mon Jan 01 00:00:00 PST 2001 is after Sat Jan 01 00:00:00 PST 2000
 * */
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainClass {
  public static void main(String[] a) throws Exception{
    DateFormat df = new SimpleDateFormat ("yyyy-MM-dd");
    Date d1 = df.parse("2001-01-01");
    Date d2 = df.parse("2000-01-01");
    String relation;
    if (d1.equals(d2))
      relation = "the same date as";
    else if (d1.before(d2))
      relation = "before";
    else if (d1.after(d2))
      relation = "after";
    System.out.println(d1 + " is " + relation + " " + d2);
  }
}

DateFormat: setLenient(boolean lenient)

 
import java.text.DateFormat;
public class Main {
  public static boolean isValidDateStr(String date) throws Exception {
    DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT);
    df.setLenient(false);
    df.parse(date);
    return true;
  }
  public static void main(String[] args) throws Exception{
    System.out.println(isValidDateStr("1900-13-12"));
  }
}

DateFormat.SHORT

 
/*
 * Output:
Japan: 4/28/06
Korea: Apr 28, 2006
United Kingdom: 28 April 2006
United States: Friday, April 28, 2006
 * */
import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;
public class MainClass {
  public static void main(String args[]) {
    Date date = new Date();
    DateFormat df;
    df = DateFormat.getDateInstance(DateFormat.SHORT, Locale.JAPAN);
    System.out.println("Japan: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.KOREA);
    System.out.println("Korea: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.LONG, Locale.UK);
    System.out.println("United Kingdom: " + df.format(date));
    df = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
    System.out.println("United States: " + df.format(date));
  }
}