How to use Java Abstract Window Toolkit (AWT) on headless Java systems
 Technote (FAQ)
 
Question
This technote explains how to use Java™ Abstract Window Toolkit (AWT) on systems where the native graphics resource is not available.
 
Cause
Sun Java bug : ID 4281163
Many environments, such as mainframe machines and dedicated servers, do not support a display, keyboard, or mouse.

Java SDK 1.3. (all releases) does not allow server-side Java applications (servlets) to use the full J2SE or J2EE™ API without a GUI environment being present, because java.awt.Graphics methods are implemented in the default JVM™ with native graphical functions.
 
Answer
There are two possible solutions.
  • For releases prior to Java SDK 1.4,
    Use another Java AWT which does not use native graphics resource (100% Pure Java AWT), or you must run an X server.

  • For Java SDK 1.4 and later,
    Use the new headless AWT toolkit. This allows you to use the J2SE API in a server-side Java application without a GUI environment.

Two new methods, are added to java.awt.GraphicsEnvironment to enable Headless support:

public static boolean isHeadless()
public boolean isHeadlessInstance()

To run your environment with a headless implementation, specify the following option at
the java command line:

-Djava.awt.headless=true
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Java SDK
Operating system(s): Solaris
Software version: 6.0
Software edition:
Reference #: 1143983
IBM Group: Software Group
Modified date: Apr 30, 2005