Add circular linked list java (#134)

linked-lists/README.md

@@ -13,6 +13,7 @@
 
 1. [Singly Linked List](java/singly.java)
 2. [Doubly Linked List](java/doubly.java)
+2. [Circular Linked List](java/circular.java)
 
 ### JavaScript
 

linked-lists/java/circular.java

@@ -0,0 +1,69 @@
+class CircularLinkedList{
+    class Node {
+        int value;
+        Node next;
+
+        public Node(int value) {
+            this.value = value;
+        }
+    }
+
+    private Node head = null;
+    private Node tail = null;
+
+    public void addNode(int value) {
+        Node newNode = new Node(value);
+
+        if (head == null) {
+            head = newNode;
+        } else {
+            tail.next = newNode;
+        }
+
+        tail = newNode;
+        tail.next = head;
+    }
+    public void printNodes() {  
+        Node current = head;  
+        if(head == null) {  
+            System.out.println("List is empty");
+            return;  
+        }    
+        System.out.println("The circular linked list is: "); 
+        System.out.print("[ "); 
+        do{   
+            System.out.print(current.value + " ");  
+            current = current.next;
+            //go to next until we get back to the head 
+        }while(current != head);
+        System.out.println("]"); 
+    }
+}
+
+public class circular {
+    public static void main(String [] args){
+        CircularLinkedList cll = new CircularLinkedList();
+
+        cll.addNode(10);
+        cll.addNode(12);
+        cll.addNode(2);
+        cll.addNode(1);
+        cll.addNode(8);
+        cll.addNode(42);
+        cll.addNode(17);
+
+        cll.printNodes();
+
+        //this will print :
+        /*
+            The circular linked list is: 
+            [ 10 12 2 1 8 42 17 ]
+        */
+    }
+}
+
+/*
+    to run the file:
+    javac circular.java
+    java circular
+*/