package com.lfsun.java9study.optional;
import java.util.Optional;
public class OptionalImprovementsExample {
public static void main(String[] args) {
// 示例1:ifPresentOrElse 方法
Optional<String> optionalValue = Optional.of("Hello, World!");
optionalValue.ifPresentOrElse(
value -> System.out.println("Value is present: " + value),
() -> System.out.println("Value is empty.")
);
// 示例2:stream 方法
Optional<String> optionalValue2 = Optional.of("Hello, World!");
optionalValue2.stream()
.map(value -> value + " Stream")
.forEach(System.out::println);
// 示例3:or 方法
Optional<String> optionalValue3 = Optional.empty();
Optional<String> backupValue = Optional.of("Backup Value");
Optional<String> result = optionalValue3.or(() -> backupValue);
System.out.println(result); // 输出:Optional[Backup Value]
}
}
Java 9 - 改进 Optional 类
猜你喜欢
转载自blog.csdn.net/qq_43116031/article/details/131818181
今日推荐
周排行