将一个列表插入到另一个列表中

Question

For instance, there are two lists

List<String> goods = new ArrayList<String>();
goods.add("Vegetables");
goods.add("Foods");
goods.add("Drinks");

List<String> foods = new ArrayList<String>();
foods.add("Beef");
foods.add("Chicken");

What is the best way to insert foods into goods into position of Foods ie into 1 position replacing the Food with the content of foods ?

So that goods will contain:

Vegetables, Beef, Chicken, Drinks

Answer 1

You can use List.addAll() , but you also have to remove the Foods entry after doing the insertion.

goods.remove("Foods");  // remove by object (String name)
goods.addAll(1, foods);

From the documentation for List.addAll(int index, Collection c) :

Inserts all of the elements in the specified collection into this list, starting at the specified position. Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices).

Answer 2

goods.addAll(1, foods);

goods.remove("Foods"); will work.

https://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html#addAll(int,%20java.util.Collection)