Standard FIs Java 8

These are just some tables that summarize Functional Interfaces.

Most important functional interfaces

Interface name Arguments Returns Example
Predicate T boolean Has this object, this attribute?
Consumer T void Printing out a value
Function<T,R> T R Get a attribute from an Object
Supplier None T A factory method
UnaryOperator T T Logical not (!)
BinaryOperator (T, T) T Multiplying two numbers (*)

Specific Purpose Functional Interfaces

API Class Method AWT KeyEventDispacter dispatchKeyEvent (KeyEvent e) AWT KeyEventPostProcessor postProcessKeyEvent (KeyEvent e)
IO FileFilter accept (File pathname)
IO FilenameFilter accept (File dir, String name)
LANG Runnable run ()
NIO DirectorStream iterator ()
NIO PathMatcher matches (Path path)
TIME TemporalAdjuster adjustInto (Temporal temporal)
TIME TemporalQuery queryFrom (TemporalAccessor temporal)
UTIL Comparator compare (T o1, T o2)
CONC Callable call ()
LOG Filter isLoggable (LogRecord record)
PREF PreferenceChangeListener preferenceChange (PreferenceChangeEvent evt)

General Purpose Functional Interfaces

Functional interfaces functional package

Consumer accept (T t)
BiConsumer accept (T t, U u)
ObjDoubleConsumer accept (T t, double value)
ObjIntConsumer accept (T t, int value)
ObjLongConsumer accept (T t, long value)
DoubleConsumer accept (double value)
IntConsumer accept (int value)
LongConsumer accept (long value)
Function apply (T t)
BiFunction apply (T t, U u)
DoubleFunction apply (double value)
IntFunction apply (int value)
LongFunction apply (long value)
BinaryOperator apply (Object, Object)
ToDoubleBiFunction applyAsDouble (T t, U u)
ToDoubleFunction applyAsDouble (T value)
IntToDoubleFunction applyAsDouble (int value)
LongToDoubleFunction applyAsDouble(long value)
DoubleBinaryOperator applyAsDouble (double left, double right)
ToIntBiFunction applyAsInt (T t, U u)
ToIntFunction applyAsInt (T value)
LongToIntFunction applyAsInt (long value)
DoubleToIntFunction applyAsInt(double value)
IntBinaryOperator applyAsInt (int left, int right)
ToLongBiFunction applyAsLong (T t, U u)
ToLongFunction applyAsLong (T value)
DoubleToLongFunction applyAsLong (double value)
IntToLongFunction applyAsLong (int value)
LongBinaryOperator applyAsLong (long left, long right)
BiPredicate test (T t, U u)
Predicate test (T t)
DoublePredicate test (double value)
IntPredicate test (int value)
LongPredicate test (long value)
Supplier get()
BooleanSupplier getAsBoolean()
DoubleSupplier getAsDouble()
IntSupplier getAsInt()
LongSupplier getAsLong()
UnaryOperator identity()
DoubleUnaryOperator identity()
IntUnaryOperator applyAsInt (int operand)
LongUnaryOperator applyAsInt (long value)