ArrayAdapter.add-->java.lang.UnsupportedOperationException

source code:

cities = new String[] { "Android", "BlackBerry", "J2ME","Symbian","Broncho", "LinuxMobile", "Palm", "WindwosMobile" }; 
cityList = Arrays.asList(cities);
arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item,cityList);

situation：
利用ArrayAdapter.add方法添加spinner item时，抛出java.lang. UnsupportedOperationException...

root cause: ArrayList size固定，导致ArrayAdapter也是resizeable

solutions：
1.在创建ArrayAdapter时，不设置固定size的ArrayList

arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item); 
cities = new String[] { "Android", "BlackBerry", "J2ME","Symbian","Broncho", "LinuxMobile", "Palm", "WindwosMobile" }; 
for(int i=0; i<cities.length; i++){
   arrayAdapter.add(cities[i]);
}

2.利用 arrayAdapter.addAll(String...items)或者 arrayAdapter.addAll(Collection<? extends String> collection),需API11及以上提供支持