question: public static boolean timeStampChanged ( String location ) { synchronized ( installLock ) { if ( fgHasChanged . contains ( location ) ) { return true ; } File file = new File ( location ) ; if ( file . exists ( ) ) { if ( fgInstallTimeMap == null ) { readInstallInfo ( ) ; } Long stamp = fgInstallTimeMap . get ( location ) ; long fstamp = file . lastModified ( ) ; if ( stamp != null ) { if ( stamp . longValue ( ) == fstamp ) { return false ; } } stamp = new Long ( fstamp ) ; fgInstallTimeMap . put ( location , stamp ) ; writeInstallInfo ( ) ; fgHasChanged . add ( location ) ; return true ; } } return false ; }
target:  Checks to see if the time stamp of the file describe by the given location string has been modified since the last recorded time stamp. If there is no last recorded time stamp we assume it has changed. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=266651 for more information