ninja-core/src/main/java/ninja/utils/HttpHeaderUtils.java
public static String getCharsetOfContentType(String rawContentType, String defaultEncoding) {
        
        if (rawContentType.contains("charset=")) {
            String charset = rawContentType.split("charset=") [1];
       
            return charset;
        } else {
            return defaultEncoding;
        }
        
    }
public static String getCharsetOfContentType(String rawContentType, String defaultEncoding) {
        
        if (rawContentType.contains("charset=")) {
            String charset = rawContentType.split("charset=") [1];
       
            return charset;
        } else {
            return defaultEncoding;
        }
        
    }
A http content type should contain a character set like
"application/json; charset=utf-8".

If you only want to get the character set you can use this method.

See also: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1

@param rawContentType "application/json; charset=utf-8" or "application/json"
@return only the character set like utf-8 OR the defaultEncoding when not set