package com.expgiga.Java8;
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;
/**
* Java8内置的四大核心函数式接口
*
* 1.Consumer<T>：消费型接口
* void accept(T t);
* 2.Supplier<T>：供给型接口
* T get();
* 3.Function<T, R>：函数型接口
* R apply(T t);
* 4.Predicate<T>：断言型接口
* boolean test(T t);
*/
public class TestLambda3 {
public static void main(String[] args) {
//Consumer<T>消费型接口
happy(
10000, (m) -> System.
out.println(
"Play Game!: " + m +
" yuan"));
//Supplier<T>
List<Integer> numList =
getNumList(
10, () -> (
int) (Math.
random() *
100));
for (Integer num : numList) {
System.
out.println(num);
}
//Function<T, R>函数型接口
String newStr =
strHandler(
"\t\t\t 你牛逼 ", (str) -> str.trim());
System.
out.println(newStr);
String subStr =
strHandler(
"我也牛逼，大家都牛逼", (str) -> str.substring(
2,
5));
System.
out.println(subStr);
//Predicate<T> 断言型接口
List<String> list = Arrays.
asList(
"Hello",
"you",
"me",
"Java",
"Scala");
List<String> newlist =
filterStr(list, (s) -> s.length() >
3);
for (String str : newlist) {
System.
out.println(str);
}
}
private static void happy(
double money, Consumer<Double> con) {
con.accept(money);
}
//需求：产生一些整数，并放入集合中
private static List<Integer> getNumList(
int num, Supplier<Integer> sup) {
List<Integer> list =
new ArrayList<>();
for (
int i =
0; i < num; i++) {
Integer n = sup.get();
list.add(n);
}
return list;
}
//需求：用于处理字符串
private static String strHandler(String str, Function<String, String> fun) {
return fun.apply(str);
}
//需求：将满足条件的字符串放入集合中去
private static List<String> filterStr(List<String> list, Predicate<String> predicate) {
List<String> strList =
new ArrayList<>();
for (String str : list) {
if (predicate.test(str)) {
strList.add(str);
}
}
return strList;
}
}
