/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/ is in libjets3t-java-doc 0.8.1+dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJButton.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJCheckBox.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJComboBox.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJHtmlLabel.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJMenuItem.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJPanel.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJPasswordField.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJPopupMenu.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJProgressBar.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJRadioButton.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJScrollPane.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJTable.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJTextArea.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedJTextField.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/SkinnedLookAndFeel.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/package-frame.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/package-summary.html
/usr/share/doc/libjets3t-java/api/org/jets3t/gui/skins/html/package-tree.html