java - try-with-resource 是否有可能无法关闭资源？

Question

根据 Oracle 文档

The try-with-resources statement is a try statement that declares one or more resources. A resource is as an object that must be closed after the program is finished with it. The try-with-resources statement ensures that each resource is closed at the end of the statement. Any object that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable, can be used as a resource

如果资源未实现 AutoCloseable，则无法在 try block 中声明它，它必须在主体部分中声明，并且必须在 finally block 中显式关闭。try-with-resource 是否有可能无法清理资源，除非您错误地使用了习惯用法，例如存在嵌套资源并且 close() 调用对于底层资源不是幂等的？我的理解是 try-with-resource 仅确保 close() 在幕后被调用，但如果 close 本身不关闭底层资源，try-with-resource 将仍然对清理资源无效。有没有人有相反的观点或更多澄清？

Answer 1

是的。

try (FileSystem fs = FileSystems.getDefault()) {
    return fs.getPath(aStringVar);
}

如果FileSystems.getDefault()返回一个sun.nio.fs.UnixFileSystem，就像我在使用Java 8 SE的RedHat机器上所做的那样，它会关闭时抛出UnsupportedOperationException。尽管 IntelliJ 显示警告并告诉您将其包装在 try-with-resources 中，但您不应该这样做，除非您想处理那个愚蠢的异常。