java - 关于 jls 一点的澄清

Question

直接来自这个jls :

A try-with-resources statement with a ResourceSpecification clause that declares multiple resources is treated as if it were multiple try-with-resources statements, each of which has a ResourceSpecification clause that declares a single Resource. When a try-with-resources statement with n Resources (n > 1) is translated, the result is a try-with-resources statement with n-1 Resources. After n such translations, there are n nested try-catch-finally statements, and the overall translation is complete.

对我来说，上述声明的最后一部分非常清楚。为什么如果我声明了 n 个资源，那么正如他们所说，结果是带有 n-1 个资源的 try-with-resources 语句？

为什么不使用 n 个资源？

提前致谢。

Answer 1

JLS 试图说的是，如果您有:

try (
   Closable closeable1 = ...;
   Closable closeable2 = ...;
   // ...
   Closable closeablen = ...;
) {
   // ...
}

它将被反复分解为:

try (Closable closeable1 = ...) {
   try (
      Closable closeable2 = ...;
      // ...
      Closable closeablen = ...;
   ) {
      // ...
   }
}

只要 try 中有多个资源，就会重复此过程。这只是一个示例，因为我假设它已分解为用于 try-with-resources 的实际字节码。