How to STORE numeric values in lucene documents?

Question

I am writing a code in java and use lucene 3.4 to index the text documents. Each document has an id and some other numerical values as well as content and title.

I add each document to the index according to the following code:

Document doc = new Document();
doc.add(new NumericField("id").setIntValue(writer.numDocs()));
doc.add(new NumericField("year").setIntValue(1988));
doc.add(new Field("content", new FileReader(file)));
writer.addDocument(doc);
writer.close();

But when I search and want to get the results, it returns null for these fields. I know that whenever I add a field and set the Field.Store.NO, it returns null , but why it happens right now? What should I do to get the value of these fields?

doc.get("id");     //why it returns null? what should I do?

Answer 1

Numeric fields are by default not stored.

Use the NumericField(String, Field.Store, boolean) constructor to specify that it should be stored if you would like to retrieve it later.