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修正 Java 10 中的 Optional 增强

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x0c 2025-07-03 16:04:11 +08:00 committed by GitHub
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docs/java/new-features/java10.md
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@ -81,11 +81,11 @@ list.stream().collect(Collectors.toUnmodifiableSet());
## Optional 增强
`Optional` 新增了`orElseThrow()`方法来在没有值时抛出指定的异常。
`Optional` 新增了一个无参的 `orElseThrow()` 方法，作为带参数的 `orElseThrow(Supplier<? extends X> exceptionSupplier)` 的简化版本，在没有值时默认抛出一个 NoSuchElementException 异常。
```java
Optional.ofNullable(cache.getIfPresent(key))
.orElseThrow(() -> new PrestoException(NOT_FOUND, "Missing entry found for key: " + key));
Optional<String> optional = Optional.empty();
String result = optional.orElseThrow();
```
## 应用程序类数据共享(扩展 CDS 功能)