The first parameter specifies the directory in which the Lucene index will be created, which is index-directory in this case. IndexWriterindexWriter = new IndexWriter("index-directory", new StandardAnalyzer(), true) You can create an IndexWriter as follows: The IndexWriter object is used to create the index and to add new index entries (i.e., Documents) to this index. To create an index, the first thing that need to do is to create an IndexWriter object. Now let us get into details on how this is done. When you're done building a Document, you write it to the Index using the IndexWriter. That is, you read in each data file (or Web document, database tuple or whatever), instantiate a Document for it, break down the data into chunks and store the chunks in the Document as Field objects (a name/value pair). Document objects are stored in the Index, and it is your job to "convert" your data into Document objects and store them to the Index. You pump your data into the Index, then do searches on the Index to get results out. Here's a simple attempt to diagram how the Lucene classes go together when you create an index:Īt the heart of Lucene is an Index. The first step in implementing full-text searching with Lucene is to build an index. Briefly go over the two java source files, Indexer.java and SearchEngine.java, to get yourself familiar with the overall structure of the code.
APACHE LUCENE BASICS CODE
The class Main in src/lucene/demo/Main.java has a test code that builds a Lucene index using a small dataset (the actual data is provided by the Hotel class stored in src/lucene/demo/business/HotelDatabase.java) and performs a simple keyword query on the data using the index. The class SearchEngine in src/lucene/demo/search/SearchEngine.java is responsible for supporting user queries. In this demo, the class Indexer in src/lucene/demo/search/Indexer.java is responsible for creating the index.
APACHE LUCENE BASICS HOW TO
In the second part, we learn how to use the prebuilt index to answer user queries. In the first part of this tutorial, we learn how to create a lucene index. (2) parsing the user query and looking up the prebuilt index to answer the query. (1) creating a lucence index on the documents and/or database objects and Roughly, supporting full-text search using Lucene requires two steps: In this tutorial, a Hotel has a unique identifier, a name, a city, and a description. The main business object is the Hotel class.
In this tutorial, we'll go through the basics of using Lucene to add full-text search functionality to a fairly typical J2EE application: an online accommodation database. You can use Lucene to provide full-text indexing across both database objects and documents in various formats (Microsoft Office documents, PDF, HTML, text, and so on). Lucene is an extremely rich and powerful full-text search library written in Java.
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