package functionalInterface;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;

/**
 * @author LiuYan
 * @date 2021年11月17日 15:08
 * <p>
 * Java8 内置的四大核心函数式接口
 * <p>
 * Consumer<T>:消费型接口
 * void accept(T t);
 * <p>
 * Supplier<T>:供给型接口
 * T get();
 * <p>
 * Function<T,R>:函数型接口
 * R apply(T t);
 * <p>
 * Predicate<T>:断言型接口
 * boolean test(T t);
 */
public class Part02 {

 public static void main(String[] args) {
 happy(100, x -> System.out.println("今天消费" + x));
 System.out.println(getNumList(10, () -> (int) (Math.random() * 100)));
 System.out.println(strHandler("\t\t\t 学习Java", str -> str.trim()));
 System.out.println(filterStr(Arrays.asList("123", "6789","7878787"), str -> str.length() > 3));
 }

 private static void happy(double money, Consumer<Double> consumer) {
 consumer.accept(money);
 }

 private static List<Integer> getNumList(int num, Supplier<Integer> supplier) {
 ArrayList<Integer> list = new ArrayList<>();
 for (int i = 0; i < num; i++) {
 list.add(supplier.get());
 }
 return list;
 }

 private static String strHandler(String str, Function<String, String> function) {
 return function.apply(str);
 }

 private static List<String> filterStr(List<String> strList, Predicate<String> predicate) {
 ArrayList<String> list = new ArrayList<>();
 for (String s : strList
 ) {
 if (predicate.test(s)) {
 list.add(s);
 }

 }
 return list;

 }


}