Does try-with-resources call dispose() method? [duplicate]

Question

I have been using try-with-resources a lot. I use it for database resource types or File stuff all the time to close the resource.

Now, I am using POI for large Excel files, and I am just noticing that I should call workbook.dispose(). Will try-with-resources call the dispose() method? Everything I looked up only covers close().

I am not convinced that the duplicate is the same question. My question specifically asks if Dispose is handled by try-with-resource. None of the other questions mention Dispose.

Answer 1

Try-with-resources only supports the AutoClosable interface and will only call the close() method. You can read more into it here.

You do have the option of using a wrapper (if necessary) which would implement AutoClosable and call dispose() in the close() method. Here is a basic example (not tested):

public class WorkbookResource implements AutoCloseable {

    private SXSSFWorkbook workbook;
    
    public WorkbookResource(SXSSFWorkbook workbook) {
        this.workbook = workbook;
    }
    
    // Delegate methods

    @Override
    public void close() throws Exception {
        workbook.dispose();
        workbook.close();
    }

}

I do not know very much about Apache POI, but you may want to verify if calling both close and dispose is necessary.

Answer 2

No, try-with-resources only works for objects that implement java.lang.AutoCloseable. That interface defines a single method: close(). That close method is the one and only method called by the try-with-resources syntax.

To quote the tutorial on try-with-resources:

Any object that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable, can be used as a resource.

Any dispose() method is not automatically called. However, the developers of these classes/libraries might have decided to call dispose() in their implementation of the close() method or vice versa. In that case both "clean up" methods would do the same.