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ArrToListTest.java
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ArrToListTest.java
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package lang;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
public class ArrToListTest {
public static void main(String[] args) {
int[] arr = new int[]{1, 2, 3};
Integer[] integersArr = new Integer[]{1, 2, 3};
String[] stringsArr = new String[]{"aa", "bb", "cc"};
//方法1:使用Collections.addAll()方法,可以执行新增add方法,只针对引用对象,效率较高,【推荐用法】
List<Integer> list = new ArrayList<>(integersArr.length);
Collections.addAll(list, integersArr);
list.add(22);
System.out.println("list = " + list);
List<String> list01 = new ArrayList<>(stringsArr.length);
Collections.addAll(list01, stringsArr);
list01.add("dd");
System.out.println("list01 = " + list01);
//方法2:new ArrayList<>(Arrays.asList(integersArr)) , 可以执行新增add方法,只针对引用对象
List<Integer> list1 = new ArrayList<>(Arrays.asList(integersArr));
list1.add(11);
System.out.println("list1 = " + list1);
//方法3:Arrays.stream(arr).boxed() 方法,使用Stream方法
List<Integer> list2 = Arrays.stream(arr).boxed().collect(Collectors.toList());
System.out.println("list2 = " + list2);
List<Integer> list21 = Arrays.stream(integersArr).collect(Collectors.toList());
System.out.println("list21 = " + list21);
}
}