我就废话不多说了，大家还是直接看代码吧~

public static void main(String[] args){ List<Integer> list1 = new ArrayList<Integer>(); list1.add(1); list1.add(2); list1.add(3); list1.add(4); List<Integer> list2 = new ArrayList<Integer>(); list2.add(1); list2.add(4); list2.add(7); list2.add(10); List<Integer> listAll = new ArrayList<Integer>(); listAll.addAll(list1); listAll.addAll(list2); listAll = new ArrayList<Integer>(new LinkedHashSet<>(listAll)); System.out.println(listAll); }

输出：

[1, 2, 3, 4, 7, 10]

代码要典：

1、合并 使用java.util.List.addAll(Collection<? extends Integer>)

2、去重,借助LinkedHashSet

补充知识：java8 lambda小试牛刀，利用Stream把list转map,并将两个list的数据对象合并起来

我就废话不多说了，大家还是直接看代码吧~

public static void main(String[] args) { // 集合1 List<SkillUpgrade> lists = new ArrayList<>(); SkillUpgrade s = new SkillUpgrade(); s.setLv(1); s.setAppearNum(100); lists.add(s); SkillUpgrade s2 = new SkillUpgrade(); s2.setLv(2); s2.setAppearNum(200); lists.add(s2); // 集合1 List<SkillUpgrade> listx = new ArrayList<>(); SkillUpgrade x = new SkillUpgrade(); x.setLv(1); x.setSelectNum(1100); listx.add(x); SkillUpgrade x2 = new SkillUpgrade(); x2.setLv(2); x2.setSelectNum(1200); listx.add(x2); // 把list转map,{k=lv,vaule=并为自身} . SkillUpgrade->SkillUpgrade或Function.identity() Map<Integer, SkillUpgrade> map = listx.stream() .collect(Collectors.toMap(SkillUpgrade::getLv, SkillUpgrade -> SkillUpgrade)); System.out.println("map:="+map); // 合并 lists.forEach(n -> { // 如果等级一致 if (map.containsKey(n.getLv())) { SkillUpgrade obj = map.get(n.getLv()); // 把数量复制过去 n.setSelectNum(obj.getSelectNum()); } }); System.out.println("lists:="+lists); // 重复问题 Map<Integer, SkillUpgrade> keyRedo = listx.stream() .collect(Collectors.toMap(SkillUpgrade::getLv, Function.identity(), (key1, key2) -> key2)); // 方式二：指定实例的map Map<Integer, SkillUpgrade> linkedHashMap = listx.stream().collect(Collectors.toMap(SkillUpgrade::getLv, SkillUpgrade -> SkillUpgrade, (key1, key2) -> key2, LinkedHashMap::new)); } /** * output:map:={1=SkillUpgrade [skillId=null, skillName=null, lv=1, persNum=null, selectNum=1100, appearNum=null], 2=SkillUpgrade [skillId=null, skillName=null, lv=2, persNum=null, selectNum=1200, appearNum=null]} * lists:=[SkillUpgrade [skillId=null, skillName=null, lv=1, persNum=null, selectNum=1100, appearNum=100], SkillUpgrade [skillId=null, skillName=null, lv=2, persNum=null, selectNum=1200, appearNum=200]] */

输出结果：

map:={1=SkillUpgrade [skillId=null, skillName=null, lv=1, persNum=null, selectNum=1100, appearNum=null], 2=SkillUpgrade [skillId=null, skillName=null, lv=2, persNum=null, selectNum=1200, appearNum=null]}

lists:=[SkillUpgrade [skillId=null, skillName=null, lv=1, persNum=null, selectNum=1100, appearNum=100], SkillUpgrade [skillId=null, skillName=null, lv=2, persNum=null, selectNum=1200, appearNum=200]]

以上这篇java 实现多个list 合并成一个去掉重复的案例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。