java - 继承和资源尝试

Question

假设有两个类实现 AutoCloseable 接口(interface)，如下所示:

public class Closing1 implements AutoCloseable {

private boolean closed;

@Override
public void close() throws Exception {
    if (closed) {
        throw new Exception("Closed Already");
    }
    this.closed = true;
    System.out.println("Closing1 closed");
}

public boolean isClosed() {
    return closed;
}

}

和

public class Closing2 implements AutoCloseable {

private Closing1 cl1;

public Closing2(Closing1 cl1) {
    this.cl1 = cl1;
}

@Override
public void close() throws Exception {
    if(!cl1.isClosed()) {
        throw new Exception("Closing1 not closed");
    }
    System.out.println("Closing2 closed");
}

}

我发现尝试资源的所有变体都会导致异常!我在这里遗漏了什么吗，或者这只是 TWR 的设计方式？

        try(Closing1 c1 = new Closing1();Closing2 c2 = new Closing2(c1)){
            System.out.println("Done");
        } //Exception while auto closing C2

或

        try(Closing1 c1 = new Closing1();Closing2 c2 = new Closing2(c1)){
            System.out.println("Done");
            c1.close();
        } // exception while auto closing c1

Answer 1

Try-with-resources 将以与声明相反的顺序关闭资源。这意味着将首先调用c2.close()，这将在您编写代码时抛出异常。