Performs this compilation task.

  Performs this compilation task. The compilation may only
be performed once. Subsequent calls to this method throw
IllegalStateException.
Returns: true if and only all the files compiled without errors; false otherwise
Throws:
- RuntimeException - if an unrecoverable error occurred in a user-supplied component. The {@linkplain Throwable#getCause() cause} will be the error in user code.
- IllegalStateException - if called more than once

  Set the locale to be applied when formatting diagnostics and other localized data.

  Set the locale to be applied when formatting diagnostics and
other localized data.
Parameters:
- locale - the locale to apply; {@code null} means apply no locale
Throws:
- IllegalStateException - if the task has started

  Sets processors (for annotation processing).

  Sets processors (for annotation processing). This will
bypass the normal discovery mechanism.
Parameters:
- processors - processors (for annotation processing)
Throws:
- IllegalStateException - if the task has started