How to avoid NPE with Collectors.summarizingInt

Our code needs to return max and min values from a list of Objects pretty much alike the following code:

import java.util.IntSummaryStatistics;
import java.util.List;
import java.util.stream.Collectors;

public class Test {

    private Short attr;

    public Short getAttr() {
        return attr;
    }

    public static void main (String[] args) {
        List<Test> tests = List.of(new Test(), new Test());

        IntSummaryStatistics i = tests.stream()
                .map(Test::getAttr)
                .map(Integer::valueOf)
                .filter(in -> in != null && in > 0)
                .collect(Collectors.summarizingInt(Integer::intValue));

        System.out.println(i.getMax() + " " + i.getMin());
    }

}

How could we avoid NPE (null pointer exception)? In case of no valid attrs we can return zero max and min.

Exception message:

Exception in thread "main" java.lang.NullPointerException
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.AbstractList$RandomAccessSpliterator.forEachRemaining(AbstractList.java:720)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578)
at Test.main(Test.java:20)

The NPE is thrown in

   .map(Integer::valueOf)

as Integer#valueOf(int) will unbox the input and cause NPE.
To solve the problem, I suggest one of the following way.

1. (Suggested by Holger) Delete .map(Integer::valueOf) and map Short to int (Short::intValue) inside Collectors.summarizingInt as follow:

IntSummaryStatistics i = tests.stream()
                .map(Test::getAttr)
                .filter(in -> in != null && in > 0)
                .collect(Collectors.summarizingInt(Short::intValue));

Please note that IntSummaryStatistics#getMax and getMin will be Integer.MIN_VALUE and Integer.MAX_VALUE respectively (not intuitive!!) when the stream is empty.
Hence the output will be -2147483648 2147483647.

2. Provide default value (maybe 0) for attr.