JDK: 1.1+
Class: java.awt.Toolkit
Platform: All
Method:
http://download.java.net/jdk7/docs/api/java/awt/Toolkit.html#getPrintJob%28java.awt.Frame,%20java.lang.String,%20java.util.Properties%29
says:
Throws:
NullPointerException - if frame is null. This exception is always thrown when GraphicsEnvironment.isHeadless() returns true.
This assertion is not satisfied.
Please compile and execute with "-Djava.awt.headless=true" the following code sample:
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import java.awt.*;
import java.util.Properties;
public class NONPE {
public static void main(String[] args) {
System.out.println("GraphicsEnvironment.isHeadless() = "
+ GraphicsEnvironment.isHeadless());
/**
* @throws NullPointerException if frame is null. This exception is
* always thrown when GraphicsEnvironment.isHeadless() returns
* true.
*/
Toolkit.getDefaultToolkit().getPrintJob(
new Frame(), "title", new Properties());
}
}
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The output will look:
GraphicsEnvironment.isHeadless() = true
Exception in thread "main" java.awt.HeadlessException
at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:197)
at java.awt.Window.<init>(Window.java:532)
at java.awt.Frame.<init>(Frame.java:420)
at java.awt.Frame.<init>(Frame.java:385)