Weird behaviour when using Java ternary operator

Question

When I write my java code like this:

Map map = new HashMap<>()
Long number =null;
if(map == null)
    number = (long) 0;
else
    numbe         


        

Answer 1

I commented above suggesting that he ensure map never be null, but that does not help with the ternary problem. As a practical matter, it's easier to let the system do the work for you. He could use Apache Commons Collections 4 and its DefaultedMap class.

import static org.apache.commons.collections4.map.DefaultedMap.defaultedMap;

Map map = ...;  // Ensure not null.
Map dMap = defaultedMap(map, 0L); 

Google Guava doesn't have anything as easy as that, but one can wrap map with the Maps.transformValues() method.