- Apache lucene indexing example how to#
- Apache lucene indexing example update#
- Apache lucene indexing example code#
The third argument is a boolean parameter set to true, which tells the IndexWriter to rebuild the index from scratch if it already exists. An analyzer represents the rules for extracting index terms from text. The second argument is a StandardAnalyzer object. The first argument is the directory location in the file system where the index files should be located. I used a constructor that takes three arguments.
Apache lucene indexing example update#
An IndexWriter object is used to create and update the index. The first thing it does is to create an index via its createIndex() method. The second text file, nicole-foods.txt, lists some foods that Nicole likes. The first one, deron-foods.txt, lists some foods that I like. Two text files in the "filesToIndex" directory will be indexed.
Apache lucene indexing example code#
Since Lucene is a fairly involved API, it can be a good idea to reference the Lucene source code and javadocs in your project build path, as shown here. The project utilizes that lucene-core jar W file. We have a directory called "indexDirectory". We have a directory called "filesToIndex" that contains text files that we are going to index. The demonstration project's structure is shown here. These are conceptually two different tasks. This example will both create an index and perform searches against the index. Likewise, when we create an index based on documents, we can query the index to find out what documents match our search terms. What is an index? An index is similar to an index at the back of the book, where you can look up search terms and find their corresponding pages in a book. In this tutorial, I'll create an index based on text files in a directory, and then I'll perform several searches on that index for various search terms.
One good way to start becoming familiar with Lucene is to begin with a simple application. In fact, Eclipse S W uses Lucene for its great search capabilities. This class will be in charge of creating the index, add all the JSON objects to the index, and finally, close the index.If you'd like to add customized search capabilities to an application, Lucene can be a great choice. I have created a class called LuceneIndexWriter which gets a directory path, and a file path which contains a number of JSON objects. JSONArray arrayObjects=(JSONArray)fileObjects Object fileObjects= JSONValue.parse(readerJson) Parse the json file using simple-json library Reader readerJson = new InputStreamReader(jsonFile) InputStream jsonFile = getClass().getResourceAsStream(jsonFilePath)
Get the JSON file, in this case is in ~/resources/test.json The file path should be included in the constructor Using json-simple, Decoding a JSON file is quite simple, you only need to call to JSONValue.parse(yourfile) With the aim to process the JSON file, I am using the json-simple library. I have a created a test file which contains 3 JSON objects, with different data types (long, String, double and boolean) In order to process a JSON file and index it, we need to: You can find all the code used in this post in github. Many companies like LinkedIn or Twitter use Lucene for Real-time search and faceted search. Apache Lucene is a high-performance, full-featured text search engine library written entirely in Java.
Apache lucene indexing example how to#
In this post, I am going to talk about how to index JavaScript Object Notation (JSON) using Lucene Core.