java - java中的合并数组

Question

我需要按对象的 id 合并数组。我的类有两个数组(本地和全局):

public class Info {
    private int id;// never change
    private String msg;
    private boolean isFavor;// presents only in local array
// constructor,getters, setters etc 
}

合并规则:

1. 如果对象不存在于全局数组中，我们不会合并它；
2. 仅从全局对象中获取消息；
3. 如果对象存在于全局数组中，我们添加(合并)它；
4. 变量“isFavor”取自本地对象；
5. 数组未排序；

示例:

local arayList = {Info(1,"msg1",false),Info(2,"msgTwo",false),Info(3,"msg3",true), Info(4,"msg4",true)};

global arayList = {Info(1,"msg1",false),Info(2,"msg2",false),Info(3,"msg3",false),Info(5,"msg5",false)}

result arayList = {Info(1,"msg1",false),Info(2,"msg2",false),Info(3,"msg3",true),Info(5,"msg5",false)}

Answer 1

所以，我做了类似的事情，我认为这符合你的要求。基本上，我所做的如下。我将所有全局值添加到 map 中，并在本地值的下一次迭代中，检查 id 是否存在，更改 isFavor。

public static void main(String[] args) throws ParseException {
    List<Info> local = new ArrayList<>();
    local.add(new Info(1,"msg1",false));
    local.add(new Info(2,"msgTwo",false));
    local.add(new Info(3,"msg3",true));
    local.add(new Info(4,"msg4",true));


    List<Info> global = new ArrayList<>();
    global.add(new Info(1,"msg1",false));
    global.add(new Info(2,"msg2",false));
    global.add(new Info(3,"msg3",false));
    global.add(new Info(4,"msg5",true));

    Map<Integer, Info> map = new HashMap<>();

    for (Info info : global) {
        if (!map.containsKey(info.id)) {
            map.put(info.id, info);
        }
    }

    for (Info info : local) {
        if (map.containsKey(info.id)){
            map.get(info.id).isFavor = info.isFavor;
        }
    }

    System.out.println(map.values());
}