1Exception in thread "main" java.util.NoSuchElementException: No value present2 at java.base/java.util.Optional.get(Optional.java:141)3 at com.cmower.dzone.optional.GetOptionalDemo.main(GetOptionalDemo.java:9)尽管抛出的异常是 NoSuchElementException 而不是 NPE，但在我们看来，显然是在“五...
System.out.println(inWhichCountryUppercase(lucy)); // 输出:Exception in thread "main" java.util.NoSuchElementException // at java.util.Optional.orElseThrow(Optional.java:290) // at com.huawei.vmf.adapter.inventory.OptionalDemo.inWhichCountryUppercase(OptionalDemo.java:47) // at com.huawei.vm...
Java documentation forjava.util.Optional. Portions of this page are modifications based on work created and shared by theAndroid Open Source Projectand used according to terms described in theCreative Commons 2.5 Attribution License. Properties
Methods declared in class java.lang.Object clone,finalize,getClass,notify,notifyAll,wait,wait,wait Method Detail empty public static <T>Optional<T> empty() Returns an emptyOptionalinstance. No value is present for thisOptional. API Note: ...
Java 8 开始新增的 Optional 类 - 创建 Optional 对象 创建一个 Optional 对象 有下面的一些方法可以被用来创建Optional对象。 empty 静态方法 如果你想创建一个空的 Optional 的对象,我们简单的使用 Optional 类提供的empty()静态方法: 代码语言:javascript...
at java.util.Optional.orElseThrow(Optional.java:290) at OptionalTest.main(OptionalTest.java:42) 示例代码: 1packagecrazy;23importjava.util.Optional;45classCompany {6privateString name;7privateOptional<Office>office;89publicCompany(String name, Optional<Office>office) {10this.name =name;11this.offic...
Java 10 以后,还推出了一个更加简单的没有参数的orElseThrow()版本的方法。 这样的话,如果 Optional 对象为空的话,我们可以抛出一个NoSuchElementException异常: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 @Test(expected=NoSuchElementException.class)publicvoidwhenNoArgOrElseThrowWorks_thenCorrect(){Str...
OptionalInt Class Reference Feedback Definition Namespace: Java.Util Assembly: Mono.Android.dll A container object which may or may not contain an int value. C# 複製 [Android.Runtime.Register("java/util/OptionalInt", ApiSince=24, DoNotGenerateAcw=true)] public sealed class OptionalInt ...
Java.IO Assembly: Mono.Android.dll Exception indicating the failure of an object read operation due to unread primitive data, or the end of data belonging to a serialized object in the stream. [Android.Runtime.Register("java/io/OptionalDataException", DoNotGenerateAcw=true)] public class Optio...
packagelambda.stream;importjava.util.Optional;/***@author作者:cb *@version创建时间:2019年1月14日 上午11:12:12 **/publicclassOptionalDemo {publicstaticvoidmain(String[] args) { testIsPresent(); }publicstaticvoidtestIsPresent() { Optional<User> optional = Optional.ofNullable(newUser());boolean...