swift dictionary 转 Json

public class DictionaryToJson: NSObject {
public static func dictionary(toJson dic: AnyObject?) -> String? {
var jsonData: Data? = nil
do {
if let dic = dic {
jsonData = try JSONSerialization.data(withJSONObject: dic, options: .prettyPrinted)
}
} catch let parseError {
print("(parseError.localizedDescription)")
}
if let jsonData = jsonData {
return String(data: jsonData, encoding: .utf8)
}
return nil
}
}