import java.util.regex.Matcher;
import java.util.regex.Pattern;
class Main {
private static final Pattern charsetPattern = Pattern.compile("(?i)\\bcharset=\\s*\"?([^\\s;\"]*)");
/**
* Parse out a charset from a content type header.
*
* @param contentType
* e.g. "text/html; charset=EUC-JP"
* @return "EUC-JP", or null if not found. Charset is trimmed and
* uppercased.
*/
static String getCharsetFromContentType(String contentType) {
if (contentType == null)
return null;
Matcher m = charsetPattern.matcher(contentType);
if (m.find()) {
return m.group(1).trim().toUpperCase();
}
return null;
}
}