java - copying array list

问题

So the below method I'm aware causes both variables to point to the same object, but if I did want to find the simplest method to has ArrayList s2 exactly the same as s1, how would I do this?

public static void main(String[] args) {

        ArrayList<String> s1 = new ArrayList<String>();
        for (int i = 1; i <= 3; i++) {
            s1.add(""+i);
        }
        ArrayList<String> s2 = s1;

    }

回答1:

You should create s2 with s1 as parameter.

public static void main(String[] args) {

    ArrayList<String> s1 = new ArrayList<String>();
    for (int i = 1; i <= 3; i++) {
        s1.add(""+i);
    }
    ArrayList<String> s2 = new ArrayList<String>(s1);

}

来源：https://stackoverflow.com/questions/10457302/java-copying-array-list