Add and use IOUtils.closeQuietly(Closeable, Throwable)

[garydgregory]

Add and use IOUtils.closeQuietly(Closeable, Throwable)

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[ppkarwasz]

Nice PR! 💯

I honestly believe this useful method was missing since Java 7 introduced addSuppressed.

[ppkarwasz]

This signature causes the following call to become ambiguous:

closeQuietly(closeable, e::addSuppressed);

Maybe we might consider inverting the order of the arguments?

[garydgregory]

There is no type casting needed in the call sites in:

• org.apache.commons.io.FileUtils.lineIterator(File, String)
• org.apache.commons.io.LineIterator.hasNext()
• org.apache.commons.io.output.FileWriterWithEncoding.initWriter(File, Object, boolean)
• org.apache.commons.io.IOUtilsTest.testCloseQuietly_CloseableIOExceptionAddSuppressed()

I would only see a typecast needed for a null literal argument, and making the method weird compared to the others for this one use case doesn't seem worth it to me.

[ppkarwasz]

Honestly I don't understand why the compiler gets confused about e::addSuppressed (which is clearly not a Throwable), but experimentally it does.
Any idea why?