public static void findAllPaths(Integer nodeId,Integer targetNodeId, Map<Integer,ArrayList<Integer>> reachMap) {

            for (Integer nextNode : reachMap.get(nodeId)) {

                if (nextNode.equals(targetNodeId)) {

                    Stack temp = new Stack();

                    for (Integer node1 : connectionPath) {

                        temp.add(node1);

                    }

                    temp.push(demandRouterArray[1]);

                    temp.add(0, demandRouterArray[0]);

                    connectionPaths.add(temp);

                } else if (!connectionPath.contains(nextNode)) {

                    connectionPath.push(nextNode);

                    findAllPaths(nextNode, targetNodeId,reachMap);

                    connectionPath.pop();

                }

            }

    }

 static Stack<Integer> connectionPath=new Stack();

 static List<Stack> connectionPaths=new ArrayList<>();