http://java.sun.com/j2se/1.4.2/docs/guide/awt/AWTChanges.html#headless
This option is being used when you are operating on a machine without graphics support (usually in a server configuration). You will use the option for example when you want to do some AWT/Swing operation on the server side (image manipulation). You want to check and see if you have graphics support on your server (on unix/linux run something like xcalc on the server).
Based on your information, it is your class that has problem and has nothing to do with graphics.
Daniel Watrous wrote:
Is there at least someone that could tell me where to find more
information about the option "JAVA_OPTS=-Djava.awt.headless=true"? What exactly is its purpose? Thanks in advance.
Daniel
On 5/6/05, Daniel Watrous <[EMAIL PROTECTED]> wrote:
Hello,
I have a web application that uses java.awt.Font objects to render images. The application will run in tomcat and that is where I have done development. When I first tried to run the application on a Linux box with Tomcat 5.0.25 I got the following error:
java.lang.NoClassDefFoundError at com.words2walls.customquote.CustomQuote.getQuoteFontName(Unknown Source) at com.words2walls.webapp.filters.SessionQuoteFilter.doFilter(Unknown Source)
Here is the code call that throws the error: public String getQuoteFontName() { return QuoteFontType.getInstance(this.quoteFontCode).toString(); }
And the class that is being called: /* * QuoteFontType.java * * Created on April 15, 2005, 9:41 AM */
package com.words2walls.customquote;
import java.awt.Font; import java.awt.FontFormatException; import java.util.*; import java.io.*;
import com.words2walls.customquote.exceptions.FontNotFoundException;
/** * Type safe enumeration of available fonts * * @author Daniel Watrous */ public class QuoteFontType {
private static final String pathToWebapp = "C:\\Program Files\\Apache Software Foundation\\Tomcat 5.0\\webapps\\words2walls"; private static final String pathToPackage = "\\WEB-INF\\classes\\com\\words2walls\\fonts\\"; private String fontName; private int fontCode; private Font font; private static org.apache.log4j.Category cat = org.apache.log4j.Category.getInstance(QuoteFontType.class.getName());
public static final QuoteFontType ADORABLE = new QuoteFontType(1,"Adorable","adorable.ttf"); private static final Map INSTANCES = new HashMap();
static { cat.debug("Enter Static block to place fonts in INSTANCES Map"); INSTANCES.put (ADORABLE.toInteger(), ADORABLE); cat.debug("Exit Static block with INSTANCES.size() = " + INSTANCES.size()); }
/** Creates a new instance of QuoteFontType */ private QuoteFontType(int code, String fontName, String filename) { // create a font from the font file try { File fontFile = new File (pathToWebapp+pathToPackage+filename); FileInputStream fis = new FileInputStream(fontFile); font = Font.createFont(Font.TRUETYPE_FONT, fis); } catch (Exception e) { throw new FontNotFoundException(e); } // set member variables this.font = font; this.fontCode = code; this.fontName = fontName; }
public String toString() { return fontName; }
public Integer toInteger() { return new Integer(fontCode); }
public static QuoteFontType getInstance(int code) { return (QuoteFontType) INSTANCES.get(new Integer(code)); }
public Font getFont() { return font; }
}
After some googling I found that if I set an environment variable "JAVA_OPTS=-Djava.awt.headless=true" that this error would go away. I'm not sure why this is the case, but it worked.
I am now trying to test the application on a windows machine with Tomcat 5.0.30 and I get the same error. I have set a Windows XP environment variable the same as mentioned above. I have also added the option to the Java tab of the Tomcat monitor under Java Options:.
What is the cause of this error? Is there some way that I can make it work on both Windows and Linux? Thanks in advance.
Daniel
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