com.atlassian.confluence.upgrade
Interfaces 
BuildNumberUpgradeConstraint
DatabaseUpgradeTask
DeferredUpgradeTask
UpgradeGate
UpgradeManager
UpgradeTask
Classes 
AbstractDeferredRunUpgradeTask
AbstractUpgradeManager
AbstractUpgradeTask
BuildNumber
BuildNumberComparator
BuildNumComparator
HSQL17To18PreUpgradeCleaner
IsNewerThan
IsNewerThanAndConfiguredNumberHighEnough
PluginFrameworkDependentUpgrader
UpgradeError
UpgradeLauncherServletContextListener
UpgradeUtils
VersionNumberComparator
Exceptions 
UpgradeException