Add Java Singleton solution and contributor update

Hackerrank/java-singleton.java

@@ -0,0 +1,28 @@
+import java.io.*;
+import java.util.*;
+
+class Singleton {
+    public static Singleton instance = null;
+    public String str;
+
+    private Singleton() {}
+
+    public static Singleton getSingleInstance() {
+        if (instance == null) {
+            instance = new Singleton();
+        }
+        return instance;
+    }
+}
+
+public class Solution {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        String input = sc.nextLine();
+
+        Singleton s = Singleton.getSingleInstance();
+        s.str = input;
+
+        System.out.println("Hello I am a singleton! Let me say " + s.str + " to you");
+    }
+}

README.md

@@ -102,6 +102,7 @@ In this repository, you can find the solutions (as source code) for the problems
 | [Nauman Chaudhary](https://github.com/nauman-chaudhary) <br> <img src="https://github.com/nauman-chaudhary.png" width="100" height="100">   | Pakistan   | Python |   |
 | [Gourav Rusiya](https://github.com/GouravRusiya30) <br> <img src="https://github.com/GouravRusiya30.png" width="100" height="100">   | India   | Java | https://www.hackerrank.com/gouravrusiya786  |
 | [Trushita Maurya](https://github.com/trushita23) <br> <img src="https://github.com/trushita23.png" width="100" height="100">   | India   | Java 
+| [Abbey Santos](https://github.com/AbbeyIT) <br> <img src="https://github.com/AbbeyIT.png" width="100" height="100">   | Philippines | Java |   |
 ### License
 
 [![MIT Licence](https://badges.frapsoft.com/os/mit/mit.svg?v=103)](https://github.com/ows-ali/Hacktoberfest/blob/master/LICENSE)