从下列结构中[{"code":"EAD","fields":[{"type":"number","show":true}]}]使用java的stream获取show=true的所有的fields集合

在Java中，你可以使用`Stream API`来处理这个结构，特别是`filter()`和`map()`方法来获取`fields`中`show`字段为`true`的所有元素。假设`EAD`是一个自定义的类，而`fields`是一个`List<Field>`，其中`Field`类有一个`show`属性。下面是代码示例：

import java.util.List;
import java.util.stream.Collectors;

class Field {
    private boolean show;

    // getters and setters...

    public boolean isShow() {
        return show;
    }
}

// 假设EAD对象有fields属性
EAD ead = ...;
List<Field> fieldsList = ead.getFields(); // 获取fields列表

// 使用Stream API筛选show为true的fields
List<Field> showTrueFields = fieldsList.stream()
    .filter(field -> field.isShow()) // 过滤show为true的field
    .collect(Collectors.toList()); // 将结果收集到新的列表中

相关问题

userInfo表结构为：{ "_id": { "$numberLong": "1672939910539612162" }, "region": "region2", "registerTime": { "$numberLong": "1687608531051" }, "lastLoginTime": { "$numberLong": "1688990931052" }, "liftDays": 30, "uniqId": "14fe5f1a-bdff-49b0-ab35-3b7ead6b7b90", "openId": "0d087060-c80a-48dd-ace3-3df981cba4ea", "deviceModel": "xiaomi", "country": "de", "channel": "huawei", "nick": "nick", "vip": "0", "propsMap": { "levelIn": "20", "levelFinish": "20", "dailyChallengeFinish": "7", "town": "10", "townBuild": "{1:[1,2,3,4,5],2:[1],3:[1,2,3],4:[1]}", "dailyChallengeIn": "8", "lv": "3" }, "_class": "com.dobest.model.mongo.UserInfo", "registerTimeDate": "2023-06-24 20:08:51", "lastLoginTimeDate": "2023-07-10 20:08:51" } event表结构为：{ "_id": { "$oid": "64a2b6bf1f5d3943f2e1a4e2" }, "userId": { "$numberLong": "1672939935722213448" }, "eventType": 0, "registerTime": { "$numberLong": "1687176537065" }, "date": "2023-06-21", "cnt": 4, "updateTime": { "$numberLong": "1687349337065" }, "onlineTime": { "$numberLong": "18" }, "_class": "com.dobest.model.mongo.Event", "registerTimeDate": "2023-06-19 20:08:57", "updateTimeDate": "2023-06-21 20:08:57" } 求eventType=0且2023-04-12<=date<=2023-07-12且2023-06-01 00:00:00<=registerTimeDate<2023-06-02 00:00:00且townBuild字段key为1对应的值包含3的_id总数

根据给出的userInfo和event表的结构，您可以使用以下MongoDB查询语句来获取满足条件的_id总数：

db.event.count({
    "eventType": 0,
    "date": {
        "$gte": "2023-04-12",
        "$lte": "2023-07-12"
    },
    "registerTimeDate": {
        "$gte": "2023-06-01 00:00:00",
        "$lt": "2023-06-02 00:00:00"
    },
    "townBuild.1": {
        "$in": ["3"]
    }
})

请注意，这里假设您的数据库名称为`db`，而且您需要将查询语句中的集合名称进行相应的更改。