迭代Java中的hashmap列表

Question

I have one hashmap inside hashmap like

List<Map> mapList = new ArrayList<Map>();
    for (int i = 0; i < 2; i++) {
        Map iMap = new HashMap();
        iMap.put("Comment", "");
        iMap.put("Start", "0");
        iMap.put("Max", "0");
        iMap.put("Min", "0");
        iMap.put("Price", "5000.00");
        iMap.put("DetailsID", "51");    
        mapList.add(iMap);
    }

    Map mMap = new HashMap();
    mMap.put("ID", "27");
    mMap.put("ParticipantID", "2");
    mMap.put("ItemDetails", mapList);

I want to iterate this map and put in JSONObject for that I do

try {

    JSONObject object = new JSONObject();

    Iterator iterator = mMap.entrySet().iterator();     

    while (iterator.hasNext()) {
        Map.Entry mEntry = (Map.Entry) iterator.next();
        String key = mEntry.getKey().toString();            
        String value = mEntry.getValue().toString();
        object.put(key, value);

    }

    Log.v(TAG, "Object : " + object);

the response comes like

Object : {"ItemDetails":"[{Price=5000.00, Comment=, DetailsID=51, Min=0, Max=0, StartViolation=0}, {Price=5000.00, Comment=, DetailsID=51, Min=0, Max=0, StartViolation=0}]","ID":"27","ParticipantID":"2"}

the inner list of hashmap is not iterating

Answer 1

the inner list of hashmap is not iterating

Indeed. You haven't written any code to iterate over it. When you get the ItemDetails entry, you'll have a key of "ItemDetails" and a value which is the list. Here's what you're then doing with those:

String key = mEntry.getKey().toString();            
String value = mEntry.getValue().toString();

So you're just calling toString() on the list. You need to work out what you really want to do. For example, you might want:

if (mEntry.getValue() instanceof List) {
    // Handle lists here, possibly recursively
}

Note that you'll also probably want to recurse into each Map . Again, you'll need to write code to do this. Basically, you can't assume that toString() is going to do what you need, which is the assumption you're making at the moment.

Answer 2

try to do like this:

Set<Map.Entry<String, String>> entrySet = JSONObject.entrySet();
for (Entry entry : entrySet) {
    // your code
}

Answer 3

for (Map.Entry<String, String> entry : JSONObject.entrySet()) {
    // ...
}