Over a million developers have joined DZone.

NetBeans Tip: Reload Debugging (debug-fix-nb)

DZone's Guide to

NetBeans Tip: Reload Debugging (debug-fix-nb)

· Java Zone ·
Free Resource

Download Microservices for Java Developers: A hands-on introduction to frameworks and containers. Brought to you in partnership with Red Hat.

Just few days back, I talked about that its rather a good practice to debug, not to run! While following that, I discovered another thing, which was there for quite some time, but I didn’t notice it, as I didn’t debug too often.

  <target name="debug-fix-nb" if="netbeans.home" depends="init,-pre-debug-fix,compile-single">
<fileset includes="${fix.class}*.class" dir="${build.classes.dir}"/>


Goto Installation Directory, and look for harness/common.xml It contains many Ant targets, including the above!

You must be thinking, what’s debug-fix-nb, its actually an Ant target, ran while we apply Code fixes during Debugging! Shocking, Indeed! I felt the same way too!


Why Reload Debugging?

Actually, when you apply code fixes while debugging, that particular class is reloaded to continue debugging.

Here lies the trick, while I was debugging a Module in Target Platform, I realized an error just after a break-point, so thought of fixing code, just before error could be detected.

  • Then, I came across an Icon in Toolbar,
  • whose tool-tip suggested its used for

  • So, I made changes wherever needed, and clicked on that Icon, it reloaded that class and the debugging continued, from same point!

Its a cool utility, I was unaware of, hope you won't miss using it...


  1. Debugging User FAQ's
  2. Reload Debugging (debug-fix-nb)
  3. Subscribe to more tips and Tricks

Download Building Reactive Microservices in Java: Asynchronous and Event-Based Application Design. Brought to you in partnership with Red Hat


Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}