下面的方法是我用来填充我的数组的方法。不过,我希望从我的ArrayList类型Deals_Information
中随机返回一个对象deals_information
,但我不太清楚如何。从ArrayList中检索随机对象
public void populateArray() {
databaseReference.child("FruitDeals").addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Iterable<DataSnapshot> children = dataSnapshot.getChildren();
final ArrayList<Deals_Information> myArray = new ArrayList<>();
for (DataSnapshot child : children) {
Deals_Information deals_information = child.getValue(Deals_Information.class);
myArray.add(deals_information);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
java.lang.Random是你的朋友....正如人们可能通过在google中输入java + random发现的那样。 –
[从ArrayList中检索一个随机项目]的可能重复(http://stackoverflow.com/questions/5034370/retrieving-a-random-item-from-arraylist) – moondaisy
[随机从列表中选择一个项目] (http://stackoverflow.com/questions/12487592/randomly-select-an-item-from-a-list) –