Breadth and Depth First Search in Java
There seem to be some inconsistencies here. What is s? I guess this is the stack? Also declaring a class Main is a little strange. You certainly want to have a main method, but a Main class?

Also I'd suggest you not use raw collections e.g. replace

Queue queue = new LinkedList();


with

Queue&lt;Node&gt; queue = new LinkedList&lt;Node&gt;();


You may like to consider implementing DFS recursively so that you don't have to explicitly use a stack, although that's a matter of taste. Also, where is getUnvisitedChildNode() defined?  Where are the edges of the graph actually stored? This could be e.g. an adjacency list carried around by each node, or perhaps in another object, but it should be somewhere.