The JDK currently has a number of *.resources packages in places that make them look like public API. The java.text.resources package is particularly confusing in this respect because it contains real classes. Several other packages (java.awt.resources, src/share/classes/javax/swing/plaf/basic/resources, src/share/classes/javax/swing/plaf/metal/resources) contain awt.properties files, which can be accessed through ResourceBundle.getBundle as if they were classes in a public package.

According to the Java package naming guidelines (http://sac.eng/sac/LSARC/1997/301/materials/guidelines.txt), these implementation packages should be named sun.* (when used to implement java.* API) or com.sun.*.internal (when used to implement javax.* or com.sun.* API).