Java 1.8 Concurrency feature "ConcurrentHashMap as a Set"

Java 1.8 Concurrency feature "ConcurrentHashMap as a Set"

The feature will return set of key in the map as Set.

public class VoiceConcurrentHashMap {

public static void main(String[] args) {

ConcurrentHashMap<String,String> map = new ConcurrentHashMap<String, String>();
System.out.println(map);
map.put("Lnkedin", "Networking");
map.put("Microsoft", "Windows10");
map.put("facebook", "Social");
map.put("Google", "SearchEngine");

KeySetView<String,String> set = map.keySet();
System.out.println(set);
}

}

Result : [Google, facebook, Microsoft, Lnkedin] .

Image :

ref :
Java API 

Behaviour of ConcurrentHashMap when it has Duplicate key.

Behaviour of ConcurrentHashMap when it has Duplicate key.

ConcurrentHashMap will overwrite previous value for a given key in Map. The object whos reference is lost are eligible for garage collection.

public class VoiceConcurrentHashMap {

public static void main(String[] args) {

ConcurrentHashMap<String,String> map = new ConcurrentHashMap<String, String>();
System.out.println(map);
map.put("Lnkedin", "profile");
map.put("Lnkedin", "profile");
map.put("Lnkedin", "jagdeesh");

}
}

ref :
1. Java API
2. Stackoverflow