question: public void hyperlinkUpdate ( HyperlinkEvent evt ) { JEditorPane c = getOutermostJEditorPane ( ) ; if ( c == null ) { return ; } if ( ! ( evt instanceof HTMLFrameHyperlinkEvent ) ) { c . fireHyperlinkUpdate ( evt ) ; return ; } HTMLFrameHyperlinkEvent e = ( HTMLFrameHyperlinkEvent ) evt ; if ( e . getEventType ( ) == HyperlinkEvent . EventType . ACTIVATED ) { String target = e . getTarget ( ) ; String postTarget = target ; if ( target . equals ( "_parent" ) && ! inNestedFrameSet ( ) ) { target = "_top" ; } if ( evt instanceof FormSubmitEvent ) { HTMLEditorKit kit = ( HTMLEditorKit ) c . getEditorKit ( ) ; if ( kit != null && kit . isAutoFormSubmission ( ) ) { if ( target . equals ( "_top" ) ) { try { movePostData ( c , postTarget ) ; c . setPage ( e . getURL ( ) ) ; } catch ( IOException ex ) { } } else { HTMLDocument doc = ( HTMLDocument ) c . getDocument ( ) ; doc . processHTMLFrameHyperlinkEvent ( e ) ; } } else { c . fireHyperlinkUpdate ( evt ) ; } return ; } if ( target . equals ( "_top" ) ) { try { c . setPage ( e . getURL ( ) ) ; } catch ( IOException ex ) { } } if ( ! c . isEditable ( ) ) { c . fireHyperlinkUpdate ( new HTMLFrameHyperlinkEvent ( c , e . getEventType ( ) , e . getURL ( ) , e . getDescription ( ) , getElement ( ) , e . getInputEvent ( ) , target ) ) ; } } }
target:  Notification of a change relative to a hyperlink. This method searches for the outermost JEditorPane, and then fires an HTMLFrameHyperlinkEvent to that frame.  In addition, if the target is _parent, and there is not nested framesets then the target is reset to _top.  If the target is _top, in addition to firing the event to the outermost JEditorPane, this method also invokes the setPage() method and explicitly replaces the current document with the destination url.