Hello!
Instead of MultiFields.getFields(), you can use MultiTerms.getTerms(reader,
fieldname) to get the Terms instance.
To decode your long / int values, you should be able to use
LongPoint/IntPoint.unpack to write the values into an array:
long[] val = new long[1]; // Assuming 1-D values
LongPoint.unpack(value, 0, val);
values.add(val[0]);
Hope that helps,
Froh
On Wed, Nov 22, 2023 at 11:09 AM <vvse...@gmail.com> wrote:
> Hello,
>
> In Lucene 6 I was doing this to get all values for a given field
> knowing its type:
>
> public List<Object> getDistinctValues(IndexReader reader, String fieldname,
> Class<? extends Object> type) throws IOException {
>
> List<Object> values = new ArrayList<Object>();
> Fields fields = MultiFields.getFields(reader);
> if (fields == null) return values;
>
> Terms terms = fields.terms(fieldname);
> if (terms == null) return values;
>
> TermsEnum iterator = terms.iterator();
>
> BytesRef value = iterator.next();
>
> while (value != null) {
> if (type == Long.class) {
> values.add(LegacyNumericUtils.prefixCodedToLong(value));
> } else if (type == Integer.class) {
> values.add(LegacyNumericUtils.prefixCodedToInt(value));
> } else if (type == Boolean.class) {
> values.add(LegacyNumericUtils.prefixCodedToInt(value) == 1 ?
> TRUE : FALSE);
> } else if (type == Date.class) {
> values.add(new
> Date(LegacyNumericUtils.prefixCodedToLong(value)));
> } else if (type == String.class) {
> values.add(value.utf8ToString());
> } else {
> // ...
> }
>
> value = iterator.next();
> }
>
> return values;
> }
>
> I am trying to upgrade to lucene 9.
> there were 2 changes over time:
> - LegacyNumericUtils has been removed in favor of PointBase
> - MultiFields.getFields() has been dropped, and I read we were encouraged
> to avoid fields in general
>
> what is proper way to implement getting distinct values for a specific
> field in a reader?
>
> thanks for your help,
>
> vs
>
