Unchecked call to compareTo
- by Dave Jarvis
Background
Create a Map that can be sorted by value.
Problem
The code executes as expected, but does not compile cleanly:
http://pastebin.com/bWhbHQmT
The syntax for passing Comparable as a generic parameter along to the Map.Entry<K, V> (where V must be Comparable?) -- so that the (Comparable) typecast shown in the warning can be dropped -- eludes me.
Warning
Compiler's cantankerous complaint:
SortableValueMap.java:24: warning: [unchecked] unchecked call to compareTo(T) as a member of the raw type java.lang.Comparable
return ((Comparable)entry1.getValue()).compareTo( entry2.getValue() );
Question
How can the code be changed to compile without any warnings (without suppressing them while compiling with -Xlint:unchecked)?
Related
TreeMap sort by value
How to sort a Map on the values in Java?
http://paaloliver.wordpress.com/2006/01/24/sorting-maps-in-java/
Thank you!
