新版本的变更 / Java 11
var in lambda parameters
New String methods
Reading and writing a file in one call
Optional.isEmpty
Negating a predicate: Predicate.not
Collection to array
Path.of instead of Paths.get
HTTP client in the standard library
Running a source file without compiling
Java EE modules removed
Optional.isEmpty
此示例属于完整版，可在应用商店购买：
Java Recipes
App Store
Code Recipes
App Store
已经购买？登录您的账户