Apache Lucene

Apache Lucene is a high-performance, full-featured text search engine library written in Java.

Online Documentation

This README file only contains basic setup instructions. For more comprehensive documentation, visit:

• Latest Releases: https://lucene.apache.org/core/documentation.html
• Nightly: https://ci-builds.apache.org/job/Lucene/job/Lucene-Artifacts-main/javadoc/
• Build System Documentation: help/
• Developer Documentation: dev-docs/

Building with Gradle

Basic steps:

0. Install OpenJDK 11 (or greater up until version 15)
1. Download Lucene from Apache and unpack it (or clone the git repository).
2. Run gradle launcher script (gradlew).

Step 0) Set up your development environment (OpenJDK 11 or greater)

We'll assume that you know how to get and set up the JDK - if you don't, then we suggest starting at https://jdk.java.net/ and learning more about Java, before returning to this README. Lucene runs with Java 11 or later.

Lucene uses Gradle for build control. Gradle is itself Java-based and may be incompatible with newer Java versions; you can still build and test Lucene with these Java releases, see help/tests.txt for more information.

NOTE: Lucene changed from Ant to Gradle as of release 9.0. Prior releases still use Ant.

Step 1) Checkout/Download Lucene source code

You can clone the source code from GitHub:

https://github.com/apache/lucene

or get Lucene source archives for a particular release from:

https://lucene.apache.org/core/downloads.html

Download either a zip or a tarred/gzipped version of the archive, and uncompress it into a directory of your choice.

Step 2) Run Gradle

Run "./gradlew help", this will show the main tasks that can be executed to show help sub-topics.

If you want to build Lucene, type:

./gradlew assemble

NOTE: DO NOT use gradle command that is already installed on your machine (unless you know what you'll do). The "gradle wrapper" (gradlew) does the job - downloads the correct version of it, setups necessary configurations.

The first time you run Gradle, it will create a file "gradle.properties" that contains machine-specific settings. Normally you can use this file as-is, but it can be modified if necessary.

./gradlew check will assemble Lucene and run all validation tasks (including unit tests).

./gradlew help will print a list of help guides that help understand how the build and typical workflow works.

If you want to build the documentation, type:

./gradlew documentation

Gradle build and IDE support

• IntelliJ - IntelliJ idea can import the project out of the box.
• Eclipse - Basic support (help/IDEs.txt).
• Netbeans - Not tested.

Contributing

Bug fixes, improvements and new features are always welcome! Please review the Contributing to Lucene Guide for information on contributing.

Discussion and Support

• Users Mailing List
• Developers Mailing List
• Issue Tracker
• IRC: #lucene and #lucene-dev on freenode.net