# Previewing refactoring changes

The Preview page shows the proposed effects of a refactoring action. You can use this page as follows.

- Select a node in the tree to examine a particular change.
- To examine a change inside a compilation unit, expand a compilation unit node in the tree and select one of its children.
- When selecting nodes, the compare viewer is adjusted only to show a preview for the selected node.
- Clear the checkbox for a node to exclude it from the refactoring.

Note: Excluding a node can result in compile errors when performing the refactoring without further warning.

Refactoring support

Refactoring with preview
Undoing a refactoring operation
Redoing a refactoring operation

Refactoring actions
Refactoring dialogs
Java preferences