Book Image

Apache Solr Beginner's Guide

By : Alfredo Serafini
Book Image

Apache Solr Beginner's Guide

By: Alfredo Serafini

Overview of this book

<p>With over 40 billion web pages, the importance of optimizing a search engine's performance is essential.<br /><br />Solr is an open source enterprise search platform from the Apache Lucene project. Full-text search, faceted search, hit highlighting, dynamic clustering, database integration, and rich document handling are just some of its many features. Solr is highly scalable thanks to its distributed search and index replication.<br /><br />Solr is written in Java and runs as a standalone full-text search server within a servlet container such as Apache Tomcat or Jetty. Solr uses the Lucene Java search library at its core for full-text indexing and search, and has REST-like HTTP/XML and JSON APIs that make it usable with most popular programming languages. Solr's powerful external configuration allows it to be tailored to many types of application without Java coding, and it has a plugin architecture to support more advanced customization.<br /><br />With Apache Solr Beginner's Guide you will learn how to configure your own search engine experience. Using real data as an example, you will have the chance to start writing step-by-step, simple, real-world configurations and understand when and where to adopt this technology.<br /><br />Apache Solr Beginner's Guide will start by letting you explore a simple search over real data. You will then go through a step-by-step description that gives you the chance to explore several practical features. At the end of the book you will see how Solr is used in different real-world contexts.<br /><br />Using data from public domains like DBpedia, you will define several different configurations, exploring some of the most interesting Solr features, such as faceted search and navigation, auto-suggestion, and rich document indexing. You will see how to configure different analysers for handling different data types, without programming.<br /><br />You will learn the basics of Solr, focusing on real-world examples and practical configurations.</p>
Table of Contents (19 chapters)
Apache Solr Beginner's Guide
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – using Tika and cURL to extract text from PDFs


Solr integrates many powerful components, for example, SolrCell can be used to extract text from rich text documents and even PDF files, and to help us to automatically index it, as we will see in a while. The Tika library is designed to perform the following functions:

  • Extract text from rich documents such as PDF, doc, and others

  • Extract metadata for a file

  • Identify the mime type of a file

  • Automatically identify the language used in a document

We can play with Tika to extract text from one of the PDFs in the /SolrStarterBook/resources/pdfs/ directory. We will now see how it's possible to map Tika inside Solr in order to index a PDF with a simple HTTP POST request:

  1. First of all it's important to add the SolrCell component to make it executable by a specific Solr handler. All we have to do is to add a specific configuration in solrconfig.xml:

    <config>
      <luceneMatchVersion>LUCENE_45</luceneMatchVersion>
    ...
      &lt...