蜂巢:重音字符与其非重音对应的字符

看来你想用

String subjectString = "öäü";
subjectString = Normalizer.normalize(subjectString, Normalizer.Form.NFD);

如中所述 Replace non ASCII character from string

reflect Normalizer.Form

因此,似乎必须定义单行自定义项:

public class NormalizerUDF extends UDF {
  public String evaluate(String in) {
        return Normalizer.normalize(in, Normalizer.Form.NFD);
  }
}