这是我正在研究的样本数据：

Peter   Wilkerson   27  M
James   Owen    26  M
Matt    Wo  30  M
Kenny   Chen    28  M

我创建了一个简单的 UDF 对于像这样过滤年龄：

public class IsApplicable extends FilterFunc {

    @Override
    public Boolean exec(Tuple tuple) throws IOException {
        if(tuple == null || tuple.size() > 0){
            return false;
        }
        try {
            Object object = tuple.get(0);
            if(object == null){
                return false;
            }
            int age = (Integer)object;
            return age > 28;
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

}

这是我用来使用这个自定义项的脚本：

records = LOAD '~/Documents/data.txt' AS (firstname:chararray,lastname:chararray,age:int,gender:chararray);
filtered_records = FILTER records BY com.udf.IsApplicable(age);
dump filtered_records;

转储不显示任何记录。请让我知道我错过了哪里。