1、Function
定義
public interface Function <T, R>
Represents a function that accepts one argument and produces a result.
(表明接受一個參數和産生一個結果的function)
T: the type of the input to the function(入參類型)
R: the type of the result of the function(出參類型)
調用函數
R apply(T t);
使用舉例
// 入參+1
Function<Integer, Integer> incrFunc = p -> p + 1;
// ret=7
Integer ret = incrFunc.apply(6);
2、Consumer
定義
public interface Consumer<T>
Represent an operation that accepts a single input argument and returns no result
(表明接受一個參數無傳回結果的operation,通常用于處理意外情況或額外動作)
T: the type of the input to the function(入參類型)
調用函數
void accept(T t);
使用舉例
// 列印入參
Consumer<String> con1 = str -> system.out.println("處理内容:"+str);
con1.accept("hello!");
3、Supplier
定義
public interface Supplier<T>
Represents a supplier of results(隻提供結果的supplier)
T: the type of results supplied by this supplier(結果類型)
調用函數
T get();
使用舉例
// 擷取字元串結果“hello!”
Supplier<String> supplier = () -> "hello!";
String ret = supplier.get();
4、Predicate
定義
public interface Predicate<T>
Represents a predicate(boolean-value function) of one argument(代表一個帶一個入參的斷言-boolean值函數)
T:the type of input to the predicate(入參)
調用方法
boolean test(T t);
使用舉例
// 擷取字元串等于“hello!”
Predicate<String> predicate = str -> str.equals("hello!");
// ret=false
boolean ret = predicate.test("hheee");