从HashMaps的HashMap中检索对象的问题

Question

I am writing code that iterates recursively through an XML file and populates a HashMap of HashMaps. I have been able to populate the hashmap and it looks OK. However, when I run this command

 System.out.println(map.containsKey("Mary"));

Its always false. Really not sure why it always returns false. I have also posted my recursive code and contents of the hashmap after

map.toString() 
map is { Mary
    ={24
        ={established
            ={western
                ={Profile=m}}, torn-down
            ={western
                ={Profile=b}, eastern
                ={Profile=m}}}, 44
        ={established
            ={western
                ={Profile=g}, eastern
                ={Profile=s}}, torn-down
            ={western
                ={Profile=j}, western
                ={Profile=f}}}}, Martha
    ={24
        ={established
            ={western
                ={Profile=a}}, torn-down
            ={western
                ={Profile=b}, eastern
                ={Profile=n}}}, 44
        ={established
            ={western
                ={Profile=s}, eastern
                ={Profile=j}}, torn-down
            ={western
                ={Profile=k}, eastern
                ={Profile=g}}}}}

Recursive code is:

NodeList l = doc.getElementsByTagName("Branches");
        Node n = l.item(0);
        map = new HashMap();
        recurse(n, map);

private void recurse(Node n, HashMap map){
if (n.hasChildNodes()){
    NodeList nl = n.getChildNodes();

    for(int i= 0; i< nl.getLength(); i++){
        Node node = nl.item(i);

        if(node.getNodeType() == Node.ELEMENT_NODE){
            if (!node.getNodeName().equals("Profile") ){

                map.put(node.getFirstChild().getNodeValue(), new HashMap());

                recurse(node, (HashMap)map.get(node.getFirstChild().getNodeValue()));
            }
            else {

                map.put("Profile", node.getFirstChild().getNodeValue());
                }


            }
        }       
    }

}   

Thanks!

Answer 1

As requested by the OP- and since the Discussion in comments solved his issue - I am wrapping it as answer - for future readers:

First, you should check if your keys are indeed String objects. You can do it by adding the line:

System.out.println(map.keySet().iterator().next().getClass());

Next, after we have established your keys are indeed String s, we want to check if you have invisible characters or not needed white spaces, we will do it by adding the following lines:

String s = (String)map.keySet().iterator().next(); 
System.out.println("val=" + s + " length=" + s.length());

If there is indeed invisible characters - we will know it since the length will not match.

If it is indeed the reason [and it is, as the OP said], you will have to process your strings when reading the XML to exclude this characters.

Also, as a side note - I'd recommend avoiding using raw types, and will suggest you to use generic types whenever it is possible. It will give you both more readable code, and both type safety !
If you want unlimited nesting, then I would have used the composite design pattern to achieve it.