如何在Java中克隆列表？
要克隆Java中的列表，最简单的方法是使用ArrayList.clone()方法-
示例
import java.util.ArrayList;
public class Demo {
public static void main(String args[]) {
// create an empty array list
ArrayList<StringBuilder> arrlist1 = new ArrayList<StringBuilder>();
// use add for new value
arrlist1.add(new StringBuilder("Learning-"));
// using clone to affect the objects pointed to by the references.
ArrayList arrlist2 = (ArrayList) arrlist1.clone();
// appending the string
StringBuilder strbuilder = arrlist1.get(0);
strbuilder.append("list1, list2-both pointing to the same StringBuilder");
System.out.println("The 1st list prints: ");
// both lists will print the same value, printing list1
for (int i = 0; i < arrlist1.size(); i++) {
System.out.print(arrlist1.get(i) + " ");
}
System.out.println("\nThe 2nd list prints the same i.e:");
// both lists will print the same value, printing list2
for (int i = 0; i < arrlist2.size(); i++) {
System.out.print(arrlist2.get(i));
}
}
}输出结果
The 1st list prints: Learning-list1, list2-both pointing to the same StringBuilder The 2nd list prints the same i.e: Learning-list1, list2-both pointing to the same StringBuilder
示例
让我们看另一个在Java中克隆列表的例子-
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class Example {
public static void main(String[] args) {
List<String> myList = Arrays.asList("Welcome", "to", "the", "website");
System.out.print("Initial List = "+myList);
List<String> newList = myList.stream().collect(Collectors.toList());
}
}输出结果
Initial List = [Welcome, to, the, website] Cloned List = [Welcome, to, the, website]