/usr/share/netbeans/java5/modules/ext/ is in libnb-java5-java 8.1+dfsg3-4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/netbeans/java5/modules/ext/AbsoluteLayout.jar
/usr/share/netbeans/java5/modules/ext/beansbinding-1.2.1.jar
/usr/share/netbeans/java5/modules/ext/cglib-2.2.jar
/usr/share/netbeans/java5/modules/ext/eclipselink/
/usr/share/netbeans/java5/modules/ext/eclipselink/eclipselink.jar
/usr/share/netbeans/java5/modules/ext/eclipselink/javax.persistence_2.1.0.v201304241213.jar
/usr/share/netbeans/java5/modules/ext/eclipselink/org.eclipse.persistence.jpa.jpql_2.5.2.v20140319-9ad6abd.jar
/usr/share/netbeans/java5/modules/ext/eclipselink/org.eclipse.persistence.jpa.modelgen_2.5.2.v20140319-9ad6abd.jar
/usr/share/netbeans/java5/modules/ext/junit-3.8.2.jar
/usr/share/netbeans/java5/modules/ext/nb-javac-api.jar
/usr/share/netbeans/java5/modules/ext/nb-javac-impl.jar
/usr/share/netbeans/java5/modules/ext/org-netbeans-modules-java-j2seembedded-probe.jar
/usr/share/netbeans/java5/modules/ext/org-netbeans-modules-java-j2seplatform-probe.jar