In JDK 8 a long line of text is rendered in a broken way. Starting with a certain number of characters on the line the painting gets broken, as you can see in the attached screenshot.

The problem is visible in NetBeans editor and also reliably reproducible in the Notepad java sample.

./jdk8/bin/java -jar ./jdk7/demo/jfc/Notepad/Notepad.jar

Run Notepad sample and paste a long line to it. For me the problem starts appearing with approx. 9000+ characters on the line.

This is a regression. Not reproducible with Java 7.

Related NetBeans bug for reference:
https://netbeans.org/bugzilla/show_bug.cgi?id=236032