johu@johu-laptop:~/Geogebra$ java -jar geogebra.jar
Exception in thread "main" java.awt.AWTError: Cannot load AWT toolkit: gnu.java.awt.peer.gtk.GtkToolkit
   at java.awt.Toolkit.getDefaultToolkit(libgcj.so.70)
   at geogebra.MyAppSplash.main(Unknown Source)
Caused by: java.lang.UnsatisfiedLinkError: libgtkpeer: libgtkpeer.so: cannot open shared object file: No such file or directory
   at java.lang.Runtime._load(libgcj.so.70)
   at java.lang.Runtime.loadLibrary(libgcj.so.70)
   at java.lang.System.loadLibrary(libgcj.so.70)
   at gnu.java.awt.peer.gtk.GtkToolkit.<clinit>(libgcj.so.70)
   at java.lang.Class.initializeClass(libgcj.so.70)
   at java.lang.Class.forName(libgcj.so.70)
   at java.awt.Toolkit.getDefaultToolkit(libgcj.so.70)
   ...1 more