Objectives

Let's take a look at Guava

most commonly used parts

rationale for its existence

additional resources for its use

https://github.com/google/guava

Google Guava

Guava is a set of Google's extensions to Java

not extensions in the language sense, but the library sense

provides a number of interesting libraries

caching

collections

concurrent utilities

and more

as such, there's a fair amount of ground to cover

Guava Packages

com.google.common.base

com.google.common.cache

com.google.common.collect

com.google.common.eventbus

com.google.common.io

com.google.common.net

com.google.common.primitives

com.google.common.util.concurrent

Installing Guava

... is a matter of getting the JAR file in your build

either directly

http://search.maven.org/remotecontent?filepath=com/google/guava/guava/19.0/guava-19.0.jar

or through a build tool

or build it yourself

Installing Guava

Guava via Maven

<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>19.0</version>
</dependency>

Installing Guava

Guava via Gradle

dependencies {
compile 'com.google.guava:guava:19.0'
}

Installing Guava

Guava via source

git clone https://github.com/google/guava

com.google.common.base

Extension methods

Objects: common Object operations

equal, hashCode, firstNonNull

toStringHelper – fluent interface for implementing toString()

Equivalences: equals-vs-identity distinction factory

Defaults: provide default values for JLS types

Splitter/Joiner: extension methods to split/join collections

Preconditions: series of assertion-like check methods

useful for ensuring preconditions/postconditions/etc

Throwables: extension methods making Throwable easier

com.google.common.base

String support

Strings: another extension class for Strings

CaseFormat: enum (with methods) to convert between different upper/lower case formats

LOWER_CAMEL, LOWER_HYPHEN, etc

Ascii: methods pertaining to the ASCII character set

Charsets: six common Charset objects

CharMatcher: Fluent interface for matching/parsing character strings

this is a wonderful (yet not 100%) replacement for regex

com.google.common.base

Object factory support

Supplier: interface describing the production of T

Suppliers: useful methods around Suppliers

most of these are to compose Suppliers in interesting ways

com.google.common.base

Functional (lite) programming support

Function, Predicate

Function is a wrapper around T apply(F in);

Predicate is a wrapper around bool apply(T in);

Functions: series of extension methods around Function

NOT a full functional library

very incomplete (see FJ for full functional support)

Predicates: ditto for Predicate

more extensive than Functions, but still incomplete

NOTE: these may go away when Java8 ships

com.google.common.base

Services

code performing operations on behalf of clients

RPC, web servers, chat servers, etc

Service: interface defining basic Service operations

start(), stop(), startAndWait(), stopAndWait(), state()

Two base classes commonly used for default behavior

AbstractExecutionThreadService: uses a single thread

AbstractService: manage threading manually (harder)

(both are in com.google.common.concurrent.util)

com.google.common.base

Reference type support

FinalizableReferenceQueue

FinalizableSoftReference

FinalizableWeakReference

FinalizablePhantomReference

these only matter if you use Soft/Weak/Phantom already

Summary

Guava's a good base of functionality to consider

it's just a jar file, so most of its features are "opt-in"

most developers will see best results from starting with .base and .collect packages and working from there

it's a huge pile of functionality, well-tested

Google promises continued enhancements and fixes

Credentials

Who is this guy?

Architect, Engineering Manager/Leader, "force multiplier"

Co-founder, Solidify US

http://www.solidify.dev

Principal -- Neward & Associates

Author

Professional F# 2.0 (w/Erickson, et al; Wrox, 2010)

Effective Enterprise Java (Addison-Wesley, 2004)

SSCLI Essentials (w/Stutz, et al; OReilly, 2003)

Server-Based Java Programming (Manning, 2000)

See http://www.newardassociates.com