jodd-core/src/main/java/jodd/util/StringUtil.java
public static String convertCharset(final String source, final String srcCharsetName, final String newCharsetName) {
		if (srcCharsetName.equals(newCharsetName)) {
			return source;
		}
		return StringUtil.newString(StringUtil.getBytes(source, srcCharsetName), newCharsetName);
	}
public static String convertCharset(final String source, final String srcCharsetName, final String newCharsetName) {
		if (srcCharsetName.equals(newCharsetName)) {
			return source;
		}
		return StringUtil.newString(StringUtil.getBytes(source, srcCharsetName), newCharsetName);
	}
Converts string charset. If charset names are the same, the same string is returned.