How the value of HashMap changes?

Question

I parse some xml files using XStream libraries. The result is a map for every file. When I debug, the result map is what I was looking for, but when I go to next line the value of map changes out of the blue! However it doesn't go for the next round in the "for" loop, it contains the information of next file. What can cause it?

public class Debug {
public String path = "E:\\Projects\\svn\\FANRPProduction\\WMS\\src\\main\\resources\\wms\\bpmn\\bp";
public XStream xStream;
public Map<String, List<CallActivity>> bpTpMap;

public void findBPandTP() throws IOException {
    File root = new File(path);
    File[] xmlFiles = FindAllXMLFiles.recursive(root);

    bpTpMap=new HashMap<String, List<CallActivity>>();
    for (File xml : xmlFiles) {
        if (xml != null) {
            xStream = new XStream(new StaxDriver());
            xStream.alias("definitions", CallActivity.class);
            xStream.registerConverter(new CallActivityConverter());
            bpTpMap = (Map) xStream.fromXML(xml);//Here I get correct information. For example "WMS_RBP_OutgoingWeighing"
            List<String> bpList = new ArrayList<String>(bpTpMap.keySet()); //Here I see the name of the next file in the path in bpTpMap, which is "WMS_BP_WeighingConfiguration"
        }
    }
}

}

Answer 1

I would suggest you to debug with the following:

bpTpMap = (Map) xStream.fromXML(xml);//Here I get correct information. For example "WMS_RBP_OutgoingWeighing"

System.out.println(bpTpMap.size());
Set<String> setOfKeys = bpTpMap.keySet();
System.out.println("Initial value of keys:"+bpTpMap);//Here you would see any extra values if the map has it