Java8 Lambda 速记手册

发表于

作为参数使用

Function<T, R> T作为输入，返回的R作为输出

1
2
3
4
5
6
Function<String, String> function = (x) -> {
  System.out.print(x+": ");
  return "Function";
};
String result = function.apply("hello world");

Predicate<T> T作为输入，返回的boolean值作为输出

1
2
3
4
5
6
7
Predicate<String> pre = (x) ->{
  System.out.print(x);
  return false;
};
boolean result = pre.test("hello World");

Consumer<T> T作为输入，执行某种动作但没有返回值

1
2
3
Consumer<String> consumer = (x) -> {System.out.println(x);};
consumer.accept("hello world");

Supplier<T> 没有任何输入，返回T

1
2
3
Supplier<String> supp = () -> {return "Supplier";};
String result = supp.get();

BinaryOperator<T> 两个T作为输入，返回一个T作为输出，对于“reduce”操作很有用

1
2
3
4
5
BinaryOperator<String> bina = (x, y) ->{
  return x + " " + y;	
};
String result = bina.apply("hello", "world");