资源是否在最终之前或之后关闭？ [英] Are resources closed before or after the finally?

问题描述

在Java 7的try-with-resources中，我不知道finally块和自动关闭发生了哪个顺序。订单是什么？

In Java 7's try-with-resources, I don't know which order the finally block and the auto-closing happens. What's the order?

BaseResource b = new BaseResource(); // not auto-closeable; must be stop'ed
try(AdvancedResource a = new AdvancedResource(b)) {

}
finally {
    b.stop(); // will this happen before or after a.close()?
}

推荐答案

资源在捕获之前关闭或者最后是块。请参阅此教程。

The resource gets closed before catch or finally blocks. See this tutorial.

try-with-resources语句可以像普通的try语句一样有catch和finally块。在try-with-resources语句中，任何catch或finally块在声明的资源关闭后运行。

A try-with-resources statement can have catch and finally blocks just like an ordinary try statement. In a try-with-resources statement, any catch or finally block is run after the resources declared have been closed.

评估这个是一个示例代码：

To evaluate this is a sample code:

class ClosableDummy implements Closeable {
    public void close() {
        System.out.println("closing");
    }
}

public class ClosableDemo {
    public static void main(String[] args) {
        try (ClosableDummy closableDummy = new ClosableDummy()) {
            System.out.println("try exit");
            throw new Exception();
        } catch (Exception ex) {
            System.out.println("catch");
        } finally {
            System.out.println("finally");
        }


    }
}

输出：

try exit
closing
catch
finally

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