Java中List列表去重有序和无序的6种方法

// 列表
List<String> list = new ArrayList<>();
list.add("Tom");
list.add("Jack");
list.add("Steve");
list.add("Tom");

System.out.println(list);
// [Tom, Jack, Steve, Tom]

// 去重
Set<String> set = new HashSet<>(list);
List<String> newList = new ArrayList<>(set);

System.out.println(newList);
// [Tom, Steve, Jack]

// 去重
Set<String> set = new TreeSet<>(list);
List<String> newList = new ArrayList<>(set);

System.out.println(newList);
// [Jack, Steve, Tom]

// 去重
Set<String> set = new LinkedHashSet<>(list);
List<String> newList = new ArrayList<>(set);

System.out.println(newList);
// [Tom, Jack, Steve]

// 去重
List<String> newList = new ArrayList<>();
for (String value : list) {
    if(!newList.contains(value)){
        newList.add(value);
    }
}

System.out.println(newList);
// [Tom, Jack, Steve]

// 去重
List<String> newList = list.stream().distinct().collect(Collectors.toList());

System.out.println(newList);
// [Tom, Jack, Steve]