java怎么将数组转化为list

Python017

java怎么将数组转化为list,第1张

1. String[] userid = {"aa","bb","cc"}List userList = new ArrayList()Collections.addAll(userList, userid)2. String[] userid = {"aa","bb","cc"}List userList = Arrays.asList(userid)3. 循环操作数组再add 望采纳。

//小例子

//这里注意的是，不能是基本类型，必须是包装类Byte[]可以。

public class Demo {

    public static void main(String[] args)throws Exception{

        String[] arr = {"asd","sd","df"}

        List list = Arrays.asList(arr)

        System.out.println(list)

    }

}

String[][] datas = {{"aaa","aa1","aa11"},{"bbb","bb1","bb11"},{"ccc","cc1","cc11"},

{"aaa","aa2","aa22"},{"bbb","bb2","bb22"},{"aaa","aa3","aa33"},

{"bbb","bb3","bb33"}}

Map<String , DetailModel>map = new HashMap<String , DetailModel>()

for (String[] strings : datas) {

DetailModel detail = new DetailModel()

detail.setPron(strings[0])

List<MeanPhrase>li = new ArrayList<MeanPhrase>()

MeanPhrase mean = new MeanPhrase()

mean.setMean(strings[1])

mean.setPhrase(strings[2])

li.add(mean)

detail.setMpList(li)

//如果已存在相同的key，如aaa,则在key对应的对象的list中增加元素

if(map.containsKey(detail.getPron())){

map.get(detail.getPron()).getMpList().addAll(li)

}else{//否则直接新增

map.put(detail.getPron(), detail)

}

}

//将map转为list

List<DetailModel>resultList = new ArrayList<DetailModel>(map.values())

for (DetailModel detailModel : resultList) {

System.out.println(detailModel)

}

//输出map中的值以及分组结果记录数

System.out.println("======================================")

Set<String>keySet = map.keySet()

for (String string : keySet) {

System.out.println(string+"："+map.get(string).getPron()+"："+map.get(string).getMpList().size())

}

控制台输出结果：

DetailModel [pron=aaa, mpList=[MeanPhrase [mean=aa1, phrase=aa11], MeanPhrase [mean=aa2, phrase=aa22], MeanPhrase [mean=aa3, phrase=aa33]]]

DetailModel [pron=ccc, mpList=[MeanPhrase [mean=cc1, phrase=cc11]]]

DetailModel [pron=bbb, mpList=[MeanPhrase [mean=bb1, phrase=bb11], MeanPhrase [mean=bb2, phrase=bb22], MeanPhrase [mean=bb3, phrase=bb33]]]

======================================

aaa：aaa：3

ccc：ccc：1

bbb：bbb：3

注意：DetailModel [pron=ccc, mpList=[MeanPhrase [mean=cc1, phrase=cc11]]]输出这样的形式是因为我实体类重写了toString()方法的原因，你那不重写的话输出的应该只是对象地址。