formatter.java

一个用于排队系统仿真的开源软件,有非常形象的图象仿真过程!

/*
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
package jmt.jmarkov.utils;

import java.text.DateFormat;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.StringTokenizer;

public class Formatter
{

    //--- Constant(s) ---

    public static final int LEFT = 0;
    public static final int CENTER = 1;
    public static final int RIGHT = 2;

    public static final String[] SIZES = { "B", "KB", "MB", "GB", "TB" };

    //--- Data field(s) ---

    //--- Constructor(s) ---

    //--- Method(s) ---

    public static String formatNumber(Object value, int decimal)
    {
	if ((value != null) && (value instanceof Number)) {
	    double d = ((Number)value).doubleValue();
	    return formatNumber(d, decimal);
	}
	else
	    return null;
    }

    public static String formatNumber(double number, int decimal)
    {
	if (number >= 0) {
	    NumberFormat n = NumberFormat.getNumberInstance();

	    if (decimal > 0) {
		n.setMinimumFractionDigits(decimal);
		n.setMaximumFractionDigits(decimal);
	    }

	    return n.format(number);
	}
	else {
	    return "";
	}
    }

    public static String formatNumber(double number)
    {
	return formatNumber(number, 0);
    }

    /**
     * Returns <code>value</code> (byte) formatted as a file size.
     *
     * For example value=2048 returns "2 kb".
     */
    public static String formatSize(Object value)
    {
	if ((value != null) && (value instanceof Number)) {
	    double d = ((Number)value).doubleValue();
	    return formatSize(d);
	}
	else
	    return null;
    }

    public static String formatSize(double size)
    {
	int i = 0;
	for (; i < SIZES.length - 1 && size >= 1024; i++) {
	    size /= 1024;
	}

	return formatNumber(size, 1) + " " + SIZES[i];
    }

    public static String formatLength(long i)
    {
	StringBuffer s = new StringBuffer();

	long x = (i / 1000);
	if (x > 0) {
	    s.append(x);
	    s.append(":");
	}
	x = (i % 1000) / 60;
	if (x < 10) {
	    s.append("0");
	}
	s.append(x);
	s.append(":");
	x = (i % 60);
	if (x < 10) {
	    s.append("0");
	}
	s.append(x);

	return s.toString();
    }

    public static String formatTime(long time)
    {
	return DateFormat.getDateInstance().format(new Date(time));
    }

    public static String formatTable(String[] rows, int[] colAlignment)
    {
	if (rows.length == 0) {
	    return "(list is empty)";
	}

	int[] widths = new int[colAlignment.length];

	for (int i = 0; i < rows.length; i++) {
	    StringTokenizer t = new StringTokenizer(rows[i], "|");
	    for (int col = 0; t.hasMoreTokens(); col++) {
		int l = t.nextToken().length();
		if (l > widths[col]) {
		    widths[col] = l;
		}
	    }
	}

	StringBuffer sb = new StringBuffer();
	for (int i = 0; i < rows.length; i++) {
	    StringTokenizer t = new StringTokenizer(rows[i], "|");
	    for (int col = 0; col < colAlignment.length; col++) {
		String s = (t.hasMoreTokens()) ? t.nextToken() : "";
		int appendCount = widths[col] - s.length();

		switch (colAlignment[col]) {
		case LEFT:
		    sb.append(s);
		    sb.append(fill(" ", appendCount));
		    break;
		case CENTER:
		    int a = appendCount / 2;
		    sb.append(fill(" ", a));
		    sb.append(s);
		    sb.append(fill(" ", appendCount - a));
		    break;
		case RIGHT:
		    sb.append(fill(" ", appendCount));
		    sb.append(s);
		    break;
		}

		if (col < colAlignment.length - 1) {
		    sb.append(" | ");
		}
	    }
	    sb.append("\n");
	}

	return sb.toString();
    }


    public static String fill(String s, int count)
    {
	StringBuffer sb = new StringBuffer(count);
	for (int i = 0; i < count; i++) {
	    sb.append(s);
	}
	return sb.toString();
    }


    /**
     * Returns the current date in the format needed for CLF
     *
     * Example: 15/Dec/2002:23:46:16
     */
    public static String getCLFDate()
    {
	String pattern = "dd/MMM/yyyy:HH:mm:ss";
	SimpleDateFormat df = new SimpleDateFormat(pattern);
	return df.format(new Date());
    }


    public static String shortDate()
    {
	return DateFormat.getTimeInstance(DateFormat.SHORT).format(new Date());
    }
}