java ArrayList set等转化

java ArrayList set等转化 java ArrayList set等转化 数组和ArrayList转化

String[] arr = new String[]{"1","2"};
List strings = Arrays.asList(arr);

String[] strings1 = strings.toArray(new String[0]);

list 和set 转化

String[] arr = new String[]{"1","2"};
List strings = Arrays.asList(arr);
Set set = new HashSet<>(strings);
List strings1 = new ArrayList<>(set);

list 和map转化

String[] arr = new String[]{"1","2"};
List strings = Arrays.asList(arr);
Set set = new HashSet<>(strings);
List strings1 = new ArrayList<>(set);
Map collect = strings1.stream().collect(Collectors.toMap(item -> item, item -> item));