java - 在java中保持地址空间相同

Question

我试图保持我的地址相同，因为我有一个指向 listAccts 的 JList。如何使 ListAccts 具有相同的地址空间？基本上，我如何复制这个对象？

public class BankEngine extends AbstractListModel {

/** holds the accounts inside the bank engine */
private ArrayList<Account> listAccts;
/** holds all the actions the user has done. */
private ArrayList<Action> actions;
/** holds old versions of the bank. */
private ArrayList<ArrayList<Account>> oldEngines;

/*****************************************************************
 * Constructor that creates a new BankEngine, the core of the project
 ******************************************************************/
public BankEngine() {
    listAccts = new ArrayList<Account>();
    // actions = new ArrayList<Action>();
    oldEngines = new ArrayList<ArrayList<Account>>();
    oldEngines.add(listAccts);
}
public void undo() {
    if (oldEngines.size() == 0) {

    } else {
        listAccts = oldEngines.get(oldEngines.size()-1); <--- I want this to have the same listAccts pointer.

}

Answer 1

java进程中的所有对象共享相同的地址空间，即正在运行的JVM的地址空间