Assigning operators in Java

I have two ArrayLists in Java:

mProductList = new ArrayList<ProductSample>();
mProductList2 = new ArrayList<ProductSample>();

mProductList = productSampleList;

mProductList2 = productSampleList;

mProductList2 .remove(3);

The size of the productsamplelist is 5 Why after executing this code The size of the mproductlist is 4?

Is there any way we can avoid this? I want the size of the mproductlist to be 5, the same as the productsamplelist thank you!

Solution

Try this:

mProductList2 = new ArrayList<ProductSample>(productSampleList);

As at present, productsamplelist, mproductlist and mproductlist2 all point to the same object, so changes to other objects will be reflected on other objects My solution is to simply create a copy of the list that can be modified independently of the original file, but remember: productsamplelist and mproductlist still point to the same object