# Compiling Single Files

You can use the Build -> Compile File command to build only the file loaded in the main source editor window.

The Java WorkShop builder determines the rules to build that file using the following criteria:

- If the file is found to be in the current project or one of its sub-projects, the builder uses the build attributes from the project that contains the file.

- If the file is not found in the current project or one of its sub-projects, the build attributes for the current project are used with the following exceptions:
  - The compiled class file is placed in the same directory as the source file.
  - The `CLASSPATH` variable is set to contain only the JDK.

See also:

  Building Projects
  Javac Help Page
  jwsbuild -- Batch Builder
  Editing Source
  Editing Project Attributes