Guava: Google Core Libraries for Java
=====================================

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Guava is a set of core libraries that includes new collection types (such as
multimap and multiset), immutable collections, a graph library, functional
types, an in-memory cache, and APIs/utilities for concurrency, I/O, hashing,
primitives, reflection, string processing, and much more!

Requires JDK 1.6 or higher (as of 12.0).

Latest release
--------------

The most recent release is [Guava 20.0][], released October 28, 2016.

- 20.0 API Docs: [guava][guava-release-api-docs], [guava-testlib][testlib-release-api-docs]
- 20.0 API Diffs from 19.0: [guava][guava-release-api-diffs]

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

```xml
<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava</artifactId>
  <version>20.0</version>
</dependency>
```

To add a dependency using Gradle:

```
dependencies {
  compile 'com.google.guava:guava:20.0'
}
```

Snapshots
---------

Snapshots of Guava built from the `master` branch are available through Maven
using version `21.0-SNAPSHOT`. API documentation and diffs from version 20.0
are available here:

- Snapshot API Docs: [guava][guava-snapshot-api-docs]
- Snapshot API Diffs from 20.0: [guava][guava-snapshot-api-diffs]

Learn about Guava
------------------

- Our users' guide, [Guava Explained][]
- [Presentation slides focusing on base, primitives, and io](http://guava-libraries.googlecode.com/files/Guava_for_Netflix_.pdf)
- [Presentation slides focusing on cache]( http://guava-libraries.googlecode.com/files/JavaCachingwithGuava.pdf)
- [Presentation slides focusing on util.concurrent](http://guava-libraries.googlecode.com/files/guava-concurrent-slides.pdf)
- [A nice collection](http://www.tfnico.com/presentations/google-guava) of other helpful links

Links
-----

- [GitHub project](https://github.com/google/guava)
- [Issue tracker: Report a defect or feature request](https://github.com/google/guava/issues/new)
- [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)
- [guava-discuss: For open-ended questions and discussion](http://groups.google.com/group/guava-discuss)

IMPORTANT WARNINGS
------------------

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.

[Guava 20.0]: https://github.com/google/guava/wiki/Release19
[guava-release-api-docs]: http://google.github.io/guava/releases/20.0/api/docs/
[testlib-release-api-docs]: http://www.javadoc.io/doc/com.google.guava/guava-testlib/20.0
[guava-release-api-diffs]: http://google.github.io/guava/releases/20.0/api/diffs/
[guava-snapshot-api-docs]: http://google.github.io/guava/releases/snapshot/api/docs/
[guava-snapshot-api-diffs]: http://google.github.io/guava/releases/snapshot/api/diffs/
[Guava Explained]: https://github.com/google/guava/wiki/Home