在java中合并数组

Question

我需要按对象的 id 合并数组。我的班级有两个数组（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：如果对象不存在于全局数组中，我们不合并它；仅从全局对象中获取 msg ；如果对象存在于全局数组中，我们添加（合并）它；变量“isFavor”取自本地对象；数组没有排序；例子：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，我做了这样的事情，我认为它可以满足你的要求。基本上，我所做的是以下内容。我将所有全局值添加到映射中，并在局部值的下一次迭代中检查 id 是否存在，然后更改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());

}

Answer 2

public Info [] merge(Info [] localArray, Info [] globalArray) {

    List<Info> resultList = new ArrayList();

    for(Info infoGlobal : globalArray) {

        Info infoLocal = findInfo(infoGlobal.getId(), localArray);

        if( infoLocal != null )

            infoGlobal.setFavor(infoLocal.isFavor());

        resultList.add(infoGlobal);

    }

    return resultList.toArray();

}

private Info findInfo(int id, Info [] infoArray) {

    for(Info info : infoArray)

        if(info.getId == id)

            return info ;

   return null ;

}