jodd-mail/src/main/java/jodd/mail/EmailUtil.java
public static String extractEncoding(final String contentType, String defaultEncoding) {
		String encoding = extractEncoding(contentType);

		if (encoding == null) {
			if (defaultEncoding == null) {
				defaultEncoding = JoddCore.encoding;
			}
			encoding = defaultEncoding;
		}
		return encoding;
	}
public static String extractEncoding(final String contentType, String defaultEncoding) {
		String encoding = extractEncoding(contentType);

		if (encoding == null) {
			if (defaultEncoding == null) {
				defaultEncoding = JoddCore.encoding;
			}
			encoding = defaultEncoding;
		}
		return encoding;
	}
Extracts encoding from a given content type.

@param contentType     content type.
@param defaultEncoding Default encoding to be used if extract returns {@code null}.
If defaultEncoding is {@code null}, {@link JoddCore#encoding} will be used.
@return Encoding from the content type.
@see #extractEncoding(String)