Guava is an open source based Java library that contains many of Google's core libraries that are being used by many of their projects. This library is designed to facilitate coding and reduce coding errors. This library provides utility methods for collections, caching, support primitives, concurrency, common annotations, string handling, I/O, and validation.
Benefits of Guava
Standardization - Guava library is hosted by Google.
Efficient - Reliable, fast and efficient extension of the JAVA standard library.
Optimization - The Guava library is highly optimized.
Functional programming - increasing JAVA functionality and processing power.
Utilities - Provides many utility classes that are frequently needed in application development.
Authentication - Provides a standard fail-safe authentication mechanism.
Best Practices - Highlights best practices.