An internal Apple developer team revealed in a new case study that “Java’s memory management approach no longer aligns with our growing demands and efficiency goals.”

The team is now looking for more efficient languages, and in this example chose Swift, achieving a claimed 50 percent reduction in hardware utilization, 90 percent less memory, and 40 percent more throughput.

It is possible that another aspect of the port, a near 85 percent reduction in lines of code, was more significant than the memory management. The team identified aspects of Swift which resulted in cleaner and more concise code, including an emphasis on protocols (interfaces) rather than inheritance, the use of async and await for concurrency, and type safety which eliminates the need for null checks.
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自己去apple的G网看，Apple有很多后端服务和企业应用是基于Java的，并且为很多开源Java项目做贡献。

【 在 hothail 的大作中提到: 】
: 啥，apple什么时候用java了
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老了，向后兼容性导致java承担了巨大的历史包袱，很多改进非常迟缓。

比如备受诟病的Java 对象模型，普通对象 (Object) 需存储对象头（16-24字节）+ 引用（4-8字节），导致小对象（如 Point、Complex）内存利用率极低，并且对象通过堆内存引用访问，导致CPU 缓存局部性差（频繁 cache miss）以及无法利用寄存器优化。

而JEP 401: Value Classes and Objects就是为了改进这个问题，搞了好几年了，貌似已经进入Preview阶段。


在比如另外一个容易把新手搞混的（尤其是从C#或者C++转过来的）Java泛型：擦除法实现，并且不支持基本类型。这个改动会涉及很多方面，比如JEP 218: Generics over Primitive Types以及上面的JEP 401都与此有关。

【 在 dawndawn001 的大作中提到: 】
: Java为啥不行了？
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