Java Jar Console Application opens Mac System Menu Bar

Question

I have a Java console application, that opens the System Menu Bar on Mac (the menubar on the top of the screen) when I run java -jar jarfile.jar <args>. I don't use Swing and I don't have any GUI. Application name in the menubar is just <package>.<mainClass>, the menu just contains e.g. About, Quit.

Since I call this multiple times when running a script, this is a bit disturbing for me and I want to disable it.

I am using gradle for building and I build the jar like this:

jar {
  baseName = 'appname'
  from(configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }) {
    exclude "META-INF/*.SF"
    exclude "META-INF/*.DSA"
    exclude "META-INF/*.RSA"
  }

  def commit = "git rev-parse --short HEAD".execute().text.trim()

  manifest {
    attributes(
      'Implementation-Title': 'appname',
      'Implementation-Version': '1.0',
      'Commit-Id': commit,
      'Built-By': System.getProperty('user.name'),
      'Built-Date': new Date(),
      'Built-JDK': System.getProperty('java.version'),
      'Main-Class': mainClassName
    )
  }
}

dependencies {
  compile 'com.lowagie:itext:2.1.3'
  compile 'com.itextpdf:itext-hyph-xml:5.1.0'
}

Is this possible? Do you need any other information? Unfortunately I don't know what causes the appearing of the menu bar, so I don't really know what else I should provide.

I created a sample gradle-project: no menu bar, even if I added my dependencies. I also tried setting the property apple.laf.useScreenMenuBar but that also didn't make any difference for me.

score 3 · Accepted Answer · answered Oct 20 '15 at 13:00

3

If you add the following command line option:

-Djava.awt.headless=true

to the java command line in your script then AWT will not attempt to initialise itself and GUI elements such as the menubar will not be presented.

answered Oct 20 '15 at 13:00

Steve C

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score 2 · Answer 2 · edited May 23 '17 at 12:25

Is this possible?

As discussed in Using Headless Mode in the Java SE Platform, certain "heavyweight components require a peer at the operating-system level." Mac OS X integrates an application containing such components into the desktop environment by adding a minimal application menu entry that can be modified as suggested here and here. The behavior is triggered when such a heavyweight component is instantiated, even lazily. Using -verbose may help identify the offending container. Bug report STS-3692 suggests that the issue is difficult to resolve with any generality.

For reference, ImageJ has a similar problem that requires the use of a special headless.jar that works in headless mode; a similar approach for gradle may be possible, for example, but I've not tried it.

Thanks for your answer too! – dinfuehr Oct 22 '15 at 18:33 — dinfuehr, Oct 22 '15 at 18:33

Java Jar Console Application opens Mac System Menu Bar

2 Answers2