How to implement our own UID in Lucene?

I wish to create an index with, lets say the following fields :

UID

title

owner

content

out of which, I don't want UID to be searchable. 开发者_开发知识库[ like meta data ]

I want the UID to behave like docID so that when I want to delete or update, I'll use this.

Is this possible ? How to do this ?

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You could mark is as non-searchable by adding it with Store.YES and Index.NO, but that wont allow you easy updating/removal by using it. You'll need to index the field to allow replacing it (using IndexWriter.UpdateDocument(Term, Document) where term = new Term("UID", "...")), so you need to use either Index.ANALYZED with a KeywordAnalyzer, or Index.NOT_ANALYZED. You can also use the FieldCache if you have a single-valued field, which a primary key usually is. However, this makes it searchable.

Summary:

• Store.NO (It can be retrieved using the FieldCache or a TermsEnum)
• Index.NOT_ANALYZED (The complete value will be indexed as a term, including any whitespaces)