访问在 catch 子句中声明的 "try-with"-资源

Question

我有一个名为 "VirtuellTx" 的可自动关闭的 class。它是一种特殊的交易，支持 "commit()"- 和 "rollback()"- 方法。如何访问 catch 块中声明的 "VirtuellTx"-资源以执行回滚 ()？

try (VirtuellTx lVtx = new VirtuellTx()) {
    // do something ...
    lVtx.commit();
} catch (Exception e) {
    lVtx.rollback();
}

catch 块无法访问 lVtx："lVtx cannot be resolved"

Answer 1

资源仅在 try-with-resources 语句块内的范围内。 JLS says:

The scope of a variable declared in the ResourceSpecification of a try-with-resources statement (§14.20.3) is from the declaration rightward over the remainder of the ResourceSpecification and the entire try block associated with the try-with-resources statement.

将catch移到里面：

try (VirtuellTx lVtx = new VirtuellTx()) {
  try {
    // do something ...
    lVTX.commit();
  } catch (Exception e) {
    lVtx.rollback();
  }
}

访问在 catch 子句中声明的 "try-with"-资源

Access declared "try-with"-resource in catch-clause

java

try-with-resources