Another Example of Fahrenheit and Celsius Temperatures Converter

package com.darwinsys;
 
import java.text.*;
 
/* Print a table of Fahrenheit and Celsius temperatures, with decimal
 * points lined up.
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: TempConverter3.java,v 1.4 2004/03/07 02:50:49 ian Exp $
 */
public class TempConverter3 extends TempConverter2 {
    protected FieldPosition fp;
    protected DecimalFormat dff;
 
    public static void main(String[] args) {
	TempConverter t = new TempConverter3();
	t.start();
	t.data();
	t.end();
    }
 
    // Constructor
    public TempConverter3() {
	super();
	dff = new DecimalFormat("#0.0");
	fp = new FieldPosition(NumberFormat.INTEGER_FIELD);
    }
 
    protected void print(float f, float c) {
	String fs = dff.format(f, new StringBuffer(), fp).toString();
	fs = prependSpaces(4 - fp.getEndIndex(), fs);
 
	String cs = df.format(c, new StringBuffer(), fp).toString();
	cs = prependSpaces(4 - fp.getEndIndex(), cs);
 
	System.out.println(fs + "  " + cs);
    }
 
    protected String prependSpaces(int n, String s) {
	String[] res = { "", " ", "  ", "   ", "    ", "     " };
	if (n < res.length)
	    return res[n] + s;
	throw new IllegalStateException("Rebuild with bigger \"res\" array.");
    }
}

package com.darwinsys;
 
import java.text.DecimalFormat;
 
/* Print a table of fahrenheit and celsius temperatures, a bit more neatly.
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: TempConverter2.java,v 1.1 2008/08/07 12:42:30 cat Exp $
 */
public class TempConverter2 extends TempConverter {
    protected DecimalFormat df;
 
    public static void main(String[] args) {
	TempConverter t = new TempConverter2();
	t.start();
	t.data();
	t.end();
    }
 
    // Constructor
    public TempConverter2() {
	df = new DecimalFormat("#0.00");
    }
 
    protected void print(float f, float c) {
	System.out.println(df.format(f) + " " + df.format(c));
    }
 
    protected void start() {
	System.out.println("Fahr    Centigrade.");
    }
 
    protected void end() {
	System.out.println("-------------------");
    }
}

package com.darwinsys;
 
/* Print a table of Fahrenheit and Celsius temperatures 
 * @author Ian F. Darwin, http://www.darwinsys.com/
 * @version $Id: TempConverter.java,v 1.1 2008/08/07 12:42:32 cat Exp $
 */
public class TempConverter {
 
    public static void main(String[] args) {
	TempConverter t = new TempConverter();
	t.start();
	t.data();
	t.end();
    }
 
    protected void start() {
    }
 
    protected void data() {
	for (int i = -40; i <= 120; i += 10) {
	    float c = (i - 32) * (5f / 9);
	    print(i, c);
	}
    }
 
    protected void print(float f, float c) {
	System.out.println(f + " " + c);
    }
 
    protected void end() {
    }
}