Package Visibility

With no modifier, the default is package visibility. From the Java Documentation, “[package visibility] indicates whether classes in the same package as the class (regardless of their parentage) have access to the member.” In this example from javax.swing,

package javax.swing;
public abstract class JComponent extends Container … {
    …
    static boolean DEBUG_GRAPHICS_LOADED;
    …
}

DebugGraphics is in the same package, so DEBUG_GRAPHICS_LOADED is accessible.

package javax.swing;
public class DebugGraphics extends Graphics {
    …
    static {
        JComponent.DEBUG_GRAPHICS_LOADED = true;
    }
    …
}

This article gives some background on the topic.