在Lucene 6.5.0中存储数值

Question

I need to Store the Numeric field in the Lucene docs, but Lucene 6.5.1 the signature of the NumericField is like

NumericDocValuesField(String name, long value)

In older lucene versions the method is like,

NumericField(String, Field.Store, boolean)

. Can someone guide me how to store the numeric values in the document using lucene6.5.1.

Regards,
Raghavan

Answer 1

NumericDocValuesField is used for scoring/sorting only: http://lucene.apache.org/core/6_5_0/core/org/apache/lucene/document/NumericDocValuesField.html

If you like to store any kind of values (including numeric) you have to use a StoredField: https://lucene.apache.org/core/6_5_0/core/org/apache/lucene/document/StoredField.html

Depending on what you need you have to add multiple fields for multiple purposes. If you have a numeric value as long and you like to do range queries and sort you would do something like this:

// for range queries
new LongPoint(field, value);
// for storing the value
new StoredField(field, value);
// for sorting / scoring
new NumericDocValuesField(field, value);

Answer 2

Use special type oriented numeric fields:

IntField intField = new IntField("int_value", 100, Field.Store.YES);
LongField longField = new LongField("long_value", 100L, Field.Store.
YES);
FloatField floatField = new FloatField("float_value", 100.0F, Field.
Store.YES);
DoubleField doubleField = new DoubleField("double_value", 100.0D, 
Field.Store.YES);

You can store their values and sort them if you need. All of those field are indexable.