Essentials - General purpose utilities and hash functions for Android and Java (aka java-common)

Essentials are a collection of general-purpose classes we found useful in many occasions. This project is bare bones compared to a rich menu offered by Guava or Apache Commons. Essentials is not a framework, it's rather a small set of utilities to make Java standard approaches more convenient or more efficient.

• IO utilities help with streams (byte and character based) and digests (e.g. MD5 and SHA-1).
• File utilities simplify reading and writing strings/bytes/objects from or to files. Also includes getting hashes from files and copying files.
• String utilities allow efficient splitting and joining of strings, hex and MD5 creation, and other useful string helpers.
  Date utilities.
• Better hash functions: Murmur3 implementation provides superior hash quality and outperforms standard Java hash functions
• Specialized Streams: for example an optimized PipedOutputStream replacement (based on a circular byte buffer)
• Hash set and map for primitive long keys outperform the generic versions of the Java Collection APIs
• Multimaps provide a map of lists or sets to simplify storing multiple values for a single key
• Object cache with powerful configuration options: soft/weak/strong references, maximum size, and time-based expiration
• Base64 implementation (bundled from iharder.net) for lower versions of Java & Android (includes input/output streams)