Is it important to add AutoCloseable in java?

Is it important to implement AutoCloseable in java?

Would it make sense if I create a class which implements AutoCloseable extends a other class which doesn't implement it?

e.g

public class IGetClosed extends ICannotBeClosed implements AutoCloseable {...}

Is it important to implement autoCloseable in java?

It is hard to tell it is important or not to implement the interface. But it is not required.

Would it make sense if I create a class which implement AutoCloseable extends a other class which doesn't implement it?

It is OK to do that. Nothing wrong.

AutoCloseable was added from Java 7. It is designed to use with new try-with-resources statement (Java 7+)

See two below classes providing the same functionality. One is not using AutoCloseable and the other is using AutoClosable:

// Not use AutoClosable
public class CloseableImpl {
    public void doSomething() throws Exception { // ... }
    public void close() throws Exception { // ...}
    
    public static void main(String[] args) {
        CloseableImpl impl = new CloseableImpl();
        try {
            impl.doSomething();

        } catch (Exception e) {
            // ex from doSomething
        } finally {
            try { //  impl.close() must be called explicitly
                impl.close();
            } catch (Exception e) { }
        }
    }
}

// Use AutoCloseable 
public class AutoCloseableImpl implements AutoCloseable {
    public void doSomething() throws Exception { // ... }
    public void close() throws Exception { // ...}

    public static void main(String[] args) {
        // impl.close() will be called implicitly

        try (AutoCloseableImpl impl = new AutoCloseableImpl()) {
            impl.doSomething();
        } catch (Exception e) {
          // ex from doSomething or close
        }
    }
}

As you see. Using AutoClosble will make the code shorter and cleaner.