http://fastutil.di.unimi.it/: fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists and priority queues with a small memory footprint and fast access and insertion; provides also big (64-bit) arrays, sets and lists, sorting algorithms, and fast, practical I/O classes for binary and text files.
  • Sebastiano Vigna 
Classes and static methods that make object and primitive-type I/O easier and faster.

 Classes in this package provide very efficient, unsynchronized buffered input and output streams (with support for repositioning, too) and fast streams based on byte arrays. 
 Static containers provide instead a wealth of methods that can be used to serialize or deserialize very easily objects and arrays, even in text form. 
/**
 * Classes and static methods that make object and primitive-type I/O easier and faster.
 *
 * <p>
 * Classes in this package provide very efficient, unsynchronized buffered
 * {@linkplain it.unimi.dsi.fastutil.io.FastBufferedInputStream input} and
 * {@linkplain it.unimi.dsi.fastutil.io.FastBufferedOutputStream output} streams (with support for
 * {@linkplain it.unimi.dsi.fastutil.io.RepositionableStream repositioning}, too) and
 * {@linkplain it.unimi.dsi.fastutil.io.FastByteArrayInputStream fast streams} based on byte arrays.
 *
 * <p>
 * Static containers provide instead a wealth of methods that can be used to
 * {@linkplain BinIO#storeObject(Object, CharSequence) serialize} or
 * {@linkplain BinIO#loadObject(CharSequence) deserialize} very easily objects and
 * {@linkplain BinIO#storeInts(int[], CharSequence) arrays}, even
 * {@linkplain TextIO#storeInts(int[], CharSequence) in text form}.
 */
package it.unimi.dsi.fastutil.io;