Measuring string bounds in headless mode on a server?

Question

I have a problem with calculating screen string width for the browser client.
I'm outputting a stream of content type application/vnd.ms-excel and sending back an XML spreadsheet. (No complaints about using Mc$oft products, it's what's needed!)
Excel does not autosize columns which contain string data, so the text columns are the standard Excel width, and the text is wrapped onto about 7 lines. See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnexcl2k2/html/odc_xmlss.asp for details of the XML format.
Excel does allow you to specify the with of a column in points, so I was using the awt Font classes to calculate the string bounds in pixels. I explicitly set the resolution to be used to 72dpi by creating a FontRenderContext with an AffineTransform with a scaling factor of (1.0, 1.0), so that asking the pixel width, gets the point width.
This worked fine testing it on my windoze machine, but on the Unix server, it's obviously running in headless mode, and anyway, it doesn't have the Arial font which I'm specifying in my spreadsheet as the font to use.
Is there any way of calculating the width of a string in points knowing its font and the point size of the font? You shouldn't need a graphcs environment, just the font information. I have all the .TTF files, I could copy them to the Unix machine if Java could use them and do the calculation.
I hate leaving the user interface looking so shoddy with wrong sized columns!
It SHOULD have worked in a headless environment according to http://java.sun.com/j2se/1.4.2/docs/guide/awt/AWTChanges.html#headless and we are on version 1.4.2_01. It actually blew up in awt code:
java.lang.NoClassDefFoundError
     at java.lang.Class.forName0(Native Method)
     at java.lang.Class.forName(Class.java:141)
     at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
     at java.awt.Font.initializeFont(Font.java:308)
     at java.awt.Font.<init>(Font.java:344)That's when I'm trying to instantiate a new Font("Arial", Font.PLAIN, 10);I've looked at the FOP project wondering whether that has a solution but it's a huge, confusing thing. There must be a way. Can anyone help?

Answer 1

When you say "unix doesn't have Arial" you obviously aren't using Solaris where Arial most certainly
ships and is in fact the main font used to support dialog & sanserif.
There are numerous APIs to calculate the width of a string in pixels, depending on whether
you want the integer metrics, fp metrics , logical bounds, pixel bounds (which guarantees to enclose
every pixel if you correctly specify the graphics/FRC)
Every single one of these works in headless mode.
Even the most simple-minded FontMetrics.stringWidth(String) call should be good enough
for your requirements.
The error you show looks like you have a misconfigured environment.. It can't find
the correct implementation class of GraphicsEnvironment which is nothing to do with
fonts. Moreover this DOES work for me :
import java.awt.*;
public class Arial {
public static void main(String args[]) {
Font arial = new Font("Arial", Font.PLAIN, 10);
System.out.println(arial);
% java -version
java version "1.4.2_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_01-b06)
Java HotSpot(TM) Client VM (build 1.4.2_01-b06, mixed mode)
% java -Djava.awt.headless=true Arial
java.awt.Font[family=Arial,name=Arial,style=plain,size=10]
QED.
-Phil.