Question

I have a HashMap<String,String> and there is a static method which returns this map to an Activity.

Method looks like this:

public static HashMap<String, String> getAll() {    
    HashMap<String, String> map = new HashMap<String,String>();

    map.put("ab", "value1");
    map.put("bc", "value2");
    map.put("de", "value3");

    return map;
}

I want to use that map with a spinner. So activity looks like this:

List list = new ArrayList<String>();
HashMap<String, String> map = Constants.getAll();

for (String key : map.keySet()) {
    list.add(Constants.getAll().get(key).toString());
}

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

spinTest = (Spinner)findViewById(R.id.spinTest);

spinTest.setOnItemSelectedListener(new OnItemSelectedListener() {
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
        urlDebug.setText(list.get(arg2).toString());
    }

    public void onNothingSelected(AdapterView<?> arg0) {

    }
});

spinTest.setAdapter(adapter);

When I tried to run my application, no problem at all. But when I clicked on spinner, items not ordered as I added on getAll() method. I mean, order has to be ab – bc -de but it’s ordered randomly.

What’s not true?

Answer 1

in hashmap, insertion order is not maintained, so item inserted last may accessed first. If you want to maintain order of insertion, use linkedhashmap instead.