JAVA lambda

Lambda

支持函数式编程

减少样板代码

使用() -> {} 替代匿名类

内部迭代取代外部迭代

Functional interface

an interface with only one method is known as a "functional interface."

函数式接口

• Predicate: A property of the object passed as argument
• Consumer: An action to be performed with the object passed as argument
• Function: Transform a T to a U
• Supplier: Provide an instance of a T (such as a factory)
• UnaryOperator: A unary operator from T -> T
• BinaryOperator: A binary operator from (T, T) -> T

Expression Syntax:

(Argument List) -> Body

(variable1, variable2)-> Action

Example:

Predicate<Integer> predicate = i -> i > 5;
Consumer<Integer> consumer = i -> System.out.println(i);
Function<Integer, String> function = i -> String.valueOf(i);
Supplier<Integer> supplier = () -> (int) Math.random() * 100;
UnaryOperator<Integer> unaryOperator = i -> i + 1;
BinaryOperator<Integer> binaryOperator = (i, j) -> i + j;

https://www.oracle.com/webfolder/technetwork/tutorials/obe/java/Lambda-QuickStart/index.html

https://docs.oracle.com/javase/8/docs/api/java/util/function/package-summary.html

http://www.importnew.com/26080.html