Lucene 4.6.1 Documentation. Permission Filtering - Lucene Tutorial.com. Lucene's keyword-based scoring system is appropriate for filtering and ranking documents based on relevancy.
It is based on a vector model, where documents are assigned a score with higher scores corresponding to more relevant documents. However, applications sometimes need to return only a subset of the relevant documents because of user-level permissions. The problem of permission filtering is actually a subset of a more generic problem of applying a boolean filter to documents at query-time. We'll examine the ways whereby this filtering can be implemented. Query rewrite The obvious method of implementing permission filtering is to rewrite the search query to require that a Field contain a certain value. For example, if there is a "category" Field, and suppose only Documents in the history and science categories are to be displayed, then given a user's query of. FilteringOptions - Lucene-java Wiki. Collector (Lucene 3.0.3 API) Java.lang.Object org.apache.lucene.search.Collector Direct Known Subclasses: PositiveScoresOnlyCollector, TimeLimitingCollector, TopDocsCollector public abstract class Collectorextends Object Expert: Collectors are primarily meant to be used to gather raw results from a search, and implement sorting or custom result filtering, collation, etc.
Lucene's core collectors are derived from Collector. TopDocsCollector is an abstract base class that assumes you will retrieve the top N docs, according to some criteria, after collection is done. Collector decouples the score from the collected doc: the score computation is skipped entirely if it's not needed. NOTE: The doc that is passed to the collect method is relative to the current reader.
Lucene in 5 minutes - Lucene Tutorial.com. Getting Started with Lucene.net. LuceneFAQ - Lucene-java Wiki. This is the official Lucene FAQ.
If you have a question about using Java Lucene, please do not add it directly to this FAQ. Join the Java User mailing list and email your question there. Questions should only be added to this Wiki page when they already have an answer that can be added at the same time. Contents General How do I start using Lucene? Zend framework - Lucene index with multiple fields of the same nature. IndexWriterConfig (Lucene 4.6.0 API) Expert: set the interval between indexed terms.
Large values cause less memory to be used by IndexReader, but slow random-access to terms. Small values cause more memory to be used by an IndexReader, and speed random-access to terms. This parameter determines the amount of computation required per query term, regardless of the number of documents that contain that term. In particular, it is the maximum number of other terms that must be scanned before a term is located and its frequency and position information may be processed.
In a large index with user-entered query terms, query processing time is likely to be dominated not by term lookup but rather by the processing of frequency and positional data. In particular, numUniqueTerms/interval terms are read into memory by an IndexReader, and, on average, interval/2 terms must be scanned for each random term access.
Takes effect immediately, but only applies to newly flushed/merged segments. Search results excerpt similar to Google. Apache Tika - Apache Tika. Index Microsoft Office Files with Lucene. Christoph Hartmann on January 7th, 2009 Within my current research project I faced the challenge to index a whole bunch of files.
To be platform independent the Java programming language was the first choice. Then I came along the Lucene project. Lucene is an open-source project that “provides Java-based indexing and search technology”. I have to mention that Lucene is a framework library instead of an out-of-the-box application. I looked at two projects: While Tika is not available as a binary download Aperture is. Just download the Tika source code viasvn checkout tika and use maven to install the binary into your local maven repository.
The following part do the core binding between Tika and Lucene. Logger.debug("Indexing " + file);try { Document doc = null; // parse the document synchronized (contentParserAccess) { doc = contentParser.getDocument(file); } // put it into Lucene if (doc ! Additionally I wrote a custom TikaParser that extracts the Exif data from JPEG files. Lucene - Index File Formats. Index File Formats This document defines the index file formats used in Lucene version 3.0.
If you are using a different version of Lucene, please consult the copy of docs/fileformats.html that was distributed with the version you are using. Lucene Query Syntax - Lucene Tutorial.com. Lucene has a custom query syntax for querying its indexes.
Here are some query examples demonstrating the query syntax. Keyword matching Search for word "foo" in the title field. title:foo Search for phrase "foo bar" in the title field. title:"foo bar" Search for phrase "foo bar" in the title field AND the phrase "quick fox" in the body field. title:"foo bar" AND body:"quick fox" Search for either the phrase "foo bar" in the title field AND the phrase "quick fox" in the body field, or the word "fox" in the title field.
(title:"foo bar" AND body:"quick fox") OR title:fox. Index and Search a Directory using Apache Lucene. Index and Search a Directory using Apache Lucene.