Two ways to sort HashMap

1  PackageTest4;2 3 Importjava.util.ArrayList;4 Importjava.util.Collections;5 ImportJava.util.Comparator;6 ImportJava.util.HashMap;7 Importjava.util.List;8 ImportJava.util.Map;9  Ten  Public classTest { One  A      Public Static voidMain (string[] args) { -map<string, integer> map =NewHashmap<string, integer>(); -Map.put ("D", 2); theMap.put ("C", 1); -Map.put ("B", 1); -Map.put ("A", 3); -  +list<map.entry<string, integer>> infoids =
NewArraylist<map.entry<string, integer>>(Map.entryset ()); +  　　　　 //ArrayList (collection<? extends e> c) is an uncommon construction method of ArrayList,
Constructs a list of elements that contain the specified collection.  A  at         //before sorting -          for(inti = 0; I < infoids.size (); i++) { -String key=Infoids.get (i). GetKey (); -             intValue=Infoids.get (i). GetValue (); -System.out.println (key+ ":" +value); -         } in         /*Output Result: - D:2 to b:1 + c:1 - A:3*/ the          *         //Sort $        //overriding the Compare methodPanax NotoginsengCollections.sort (Infoids,NewComparator<map.entry<string, integer>>() {    -              Public intCompare (map.entry<string, integer> O1, map.entry<string, integer>O2) {       the                 //return (O2.getvalue ()-o1.getvalue ());//Sort by Value +                 return(O1.getkey ()). ToString (). CompareTo (O2.getkey ());//Sort by Key A             } the         });  +  -         //after sorting $          for(inti = 0; I < infoids.size (); i++) { $String key=Infoids.get (i). GetKey (); -             intValue=Infoids.get (i). GetValue (); -System.out.println (key+ ":" +value); the         } -         //Sort by KeyWuyi         //A:3 the         //b:1 -         //c:1 Wu         //D:2 -         //Sort by Value About         //A:3 $         //D:2 -         //b:1 -         //c:1 -     } A}

Two ways to sort HashMap