在Android中保存对象数组列表的方法

Question

I am having difficulty saving an ArrayList of objects to a file in android. I want to be able be able to read these objects and call a method on each object to get one of their attributes. Here is the object class

public class Transaction {

private double amount;
private String store;
private Date date;

public Transaction(){
    amount = 0.0;
    store = null;
    date = null;
}

public Transaction(double amt, String str, Date dat ) {
    amount = amt;
    store = str;
    date = dat;
}

}

In my activity I take input and create a new Transaction object. I then add the Transaction object to an ArrayList. I want to save the ArrayList to a file and be able to access the ArrayList from a different activity. In this different activity I want to access and call getAmount() on each object in the ArrayList to create a total amount and display it on screen. Thanks.

Answer 1

You can implement Parcelable in your objects. There is online tool that can helps. Ones you implement Parcelable you can pass the ArrayList<Parcelable> trough activities by putting the array in Intent's extras or save the array in SharedPreferences for later usage.