IOUtils.close throws NPE

[TobiasKiecker]

Describe the bug
The IOUtils.close function:

atmosphere/modules/cpr/src/main/java/org/atmosphere/util/IOUtils.java

Lines 463 to 486 in d350bc5

	/**
	* <p>
	* Tries to close the given objects and log the {@link IOException} at INFO level
	* to make the code more readable when we assume that the {@link IOException} won't be managed.
	* </p>
	* <p/>
	* <p>
	* Also ignore {@code null} parameters.
	* </p>
	*
	* @param closeableArray the objects to close
	*/
	public static void close(final Closeable... closeableArray) {
	for (Closeable closeable : closeableArray) {
	try {
	if (closeable != null) {
	closeable.close();
	}
	} catch (IOException ioe) {
	logger.info("Can't close the object", ioe);
	}
	}
	}

throws a null pointer exception if it is called with one single parameter which is null.

Atmosphere Info

• version: all since b31804c
• atmosphere.js version NA
• extensions used None

Expected behavior
Should not throw null.

Screenshots

Systems (please complete the following information):

• OS: NA
• Browser name and version: NA
• Java version and distribution: at least Java 21 probably more
• Serveur name and version: NA

Additional context
This is an edge case of Java behavior of varargs.

An improved implementation could be:

if (closeableArray != null) {
    for (Closeable closeable : closeableArray) {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (IOException ioe) {
                logger.info("Can't close the object", ioe);
            }
        }
    }
}

[slovdahl]

Good catch. Just out of curiosity, have you seen this cause problems in reality?

[TobiasKiecker]

No not really, we found it as a part of a research project.