The Guava project contains several of Google's core libraries that we rely on in our Java-based projects: collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and so forth.

Requires JDK 1.6 or higher (as of 12.0).

The most recent release is Guava 18.0, released August 25, 2014.

• 18.0 API Docs: guava, guava-testlib
• 18.0 API Diffs from 17.0: guava

To add a dependency on Guava using Maven, use the following:

<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava</artifactId>
  <version>18.0</version>
</dependency>

To add a dependency using Gradle:

dependencies {
  compile 'com.google.guava:guava:18.0'
}

Guava 19.0 is the next release. A release candidate is currently available on Maven Central as version 19.0-rc2, released September 17, 2015.

Snapshots of Guava built from the master branch are available through Maven using version 19.0-SNAPSHOT. API documentation and diffs from version 18.0 are available here:

• Snapshot API Docs: guava
• Snapshot API Diffs from 18.0: guava

• Our users' guide, Guava Explained
• Presentation slides focusing on base, primitives, and io
• Presentation slides focusing on cache
• Presentation slides focusing on util.concurrent
• A nice collection of other helpful links

• GitHub project
• Issue tracker: report a defect or feature request
• StackOverflow: Ask "how-to" and "why-didn't-it-work" questions
• guava-discuss: For open-ended questions and discussion

1. APIs marked with the @Beta annotation at the class or method level are subject to change. They can be modified in any way, or even removed, at any time. If your code is a library itself (i.e. it is used on the CLASSPATH of users outside your own control), you should not use beta APIs, unless you repackage them (e.g. using ProGuard).

2. Deprecated non-beta APIs will be removed two years after the release in which they are first deprecated. You must fix your references before this time. If you don't, any manner of breakage could result (you are not guaranteed a compilation error).

3. Serialized forms of ALL objects are subject to change unless noted otherwise. Do not persist these and assume they can be read by a future version of the library.

4. Our classes are not designed to protect against a malicious caller. You should not use them for communication between trusted and untrusted code.

5. We unit-test and benchmark the libraries using only OpenJDK 1.7 on Linux. Some features, especially in com.google.common.io, may not work correctly in other environments.