Currently, the default headless message ends with a comma instead of full stop and has an additional line break.
Exception in thread "AWT-EventQueue-0" java.awt.HeadlessException: No X11 DISPLAY variable was set, or no headful library support was found, but this program performed an operation which requires it, at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:158) at java.desktop/java.awt.Window.<init>(Window.java:518) at java.desktop/java.awt.Frame.<init>(Frame.java:428) at java.desktop/javax.swing.JFrame.<init>(JFrame.java:224) **Fix:** Amend the message so that it ends with a full stop and remove the line break. Exception in thread "AWT-EventQueue-0" java.awt.HeadlessException: No X11 DISPLAY variable was set, or no headful library support was found, but this program performed an operation which requires it. at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:158) at java.desktop/java.awt.Window.<init>(Window.java:518) at java.desktop/java.awt.Frame.<init>(Frame.java:428) at java.desktop/javax.swing.JFrame.<init>(JFrame.java:224) **Testing:** Build a headless-only JDK (pass `--enable-headless-only` to the `configure` script) and create a `JFrame`. It's impossible to create an automated test for this change, and I don't think a test is required, it's a cosmetic change. ------------- Commit messages: - 8357675: Amend headless message Changes: https://git.openjdk.org/jdk/pull/25453/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25453&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8357675 Stats: 3 lines in 1 file changed: 0 ins; 1 del; 2 mod Patch: https://git.openjdk.org/jdk/pull/25453.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/25453/head:pull/25453 PR: https://git.openjdk.org/jdk/pull/25453