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APACHE LUCENE INDEXING EXAMPLE HOW TO
APACHE LUCENE INDEXING EXAMPLE CODE

Directory is the abstract interface of the data persistence layer in Lucene.

Initialization: the two elements needed to initialize IndexWriter are Directory and IndexWriterConfig.

The whole process involves three main steps:

APACHE LUCENE INDEXING EXAMPLE CODE

The above is sample code for a simple call.

APACHE LUCENE INDEXING EXAMPLE HOW TO

Let us first look at how to use IndexWriter for data writing in Lucene. IndexWriter writer = new IndexWriter(index, config) ĭoc.add(new TextField("title", "Lucene - IndexWriter", )) ĭoc.add(new StringField("author", "aliyun", )) IndexWriterConfig config = new IndexWriterConfig() IndexWriter // initializationĭirectory index = new NIOFSDirectory(Paths.get("/index")) In this article, we will delve deeper into IndexWriter, one of Lucene's core classes, to explore the whole data writing and indexing process in Lucene. As representaion of the result of a query : Field's values matching the query are gather and displayed by the search application as result.In the previous article, we presented a basic overview of Lucene.There are used as pointer on Lucene Documents they represent. Documents'identification numbers (DocIds) : These are numbers that are automatically increment when a new Lucene Document is added.Terms of each field: these build the terms dictionnary.The following components of Lucene Documents are usually stored in the index: A part of the index which hold stored (Lucene) fields.As a logical representation of the original documents(txt,pdf,html.) provided by the document parser.

Lucene Document is used in these three cases :

"/document and settings/2012/index" is an example of field value for the field name's path.

An example of a field value is "discover the web" for the field content.

The name is usually a word (String type) describing the field like content, path, name, date of creation are examples of field's names. A Field comprises a name and one or more values. Let's start by the Lucene Document.Ī Lucene Document is a set of Fields. The next step is to delve into each component of this process. To prevent concurrency, a Lock is used to avoid other IndexWriters to open the same Index directory. We can also choose not to limit the length of a field, so all the terms in a field should be considered. In this case we choose the simplest one, the StandardAnalyzer for the version 3.0 of Lucene.

The Analyzer is a startegy used by the IndexWriter to analyze the Lucene Documents fields before they are stored. the Index files would be stored in indexdir New StandardAnalyzer(version.LUCENE_30,)) įSDirectory is an Implementation of Directory, that store the index in a new or an existing directory in the computer. IndexWriter W = new IndexWriter(FSDirectory.open(indexdir), This is one of the Syntax to use to create an IndexWriter: Once Lucene Document are created the second process is taken over by the IndexWriter, this one is used to create and maintain the Index: IndexWriter's addDocument(LuceneDocument) method gather Lucene Document Fields Value into the Index. It is the responsibility of the search engine application to convert original data(PDF,Html,Txt.) into Lucene Document(field,value), using an appropriate document parser(exple. The first one populates Lucene Documents with Fields. The creation of an Index involves two different processes.