查询内存中集合 [英] querying in-memory collection

问题描述

我有一个集合，一个地图列表，地图是 Map< String，String> 。我需要通过比较，逻辑，喜欢，不在运算符中查询此集合。类似SQL的东西。

I have a collection, a List of Map, the map is Map<String, String>. I need to query this collection with comparison, logical, like, not in operators. Something like SQL.

我将从数据库存储过程填充列表，所以我不知道大小。但是，我想这个大小不应该超过10,000条记录。

I will be populating the list from a database stored procedure, so I am not sure about the size. But, I guess the size should not be more than 10,000 records.

发布这个时候，我看看Apache函子，我不知道他们会帮助这里。

While posting this I am having a look at Apache functors, I don't know if they will help here.

我想到的其他方法是使用内存数据库Derby来实现这一点。

Other way that I am thinking of is using the in-memory database Derby to achieve this.

请让我知道任何Java库或任何其他方式这样做。

Please let me know of any Java library or any other way of doing this.

列表中的地图将如下所示：

The maps in the list will be like below:

Map<String, String> m1 = new Map<String, String>();
m1.put("name","Mark");
m1.put("age","21");
m1.put("city","some city");

Map<String, String> m1 = new Map<String, String>();
m1.put("name","David");
m1.put("age","25");
m1.put("city","other city");

我需要查询列表以获取Map，其中包含：

I need to query the list to get Map which has:

1. name = Mark


2. name = Mark年龄> 30


3. 城市不在其他城市

1. name=Mark
2. name=Mark and age > 30
3. city not in "other city"

推荐答案

我发现 JFilter ，它可以帮助您过滤内存数据（java对象）。下面是JFilter网站的描述。

I found JFilter which helps you with filtering in-memory data (java objects ). Below is the description from JFilter website.

JFilter是一个简单和高性能的开源库，用于过滤（查询），映射（选择） Java集合。查询以json格式给出，如Mongodb查询。

JFilter is a simple and high performance open source library to filter (query), map (select) and reduce (aggregate) objects in a Java collection. Query is given in json format like Mongodb queries.

我写了一个 post ，了解如何使用 JFilter 和我使用 JFilter存储数据和查询/过滤的一般方法

I have written a post on using JFilter with Maps, which I am using as a generic way of storing data and querying/filtering using JFilter

以下是帖子的链接使用 JFilter查询/过滤内存数据

Here is the link to the post Using JFilter to query/filter in-memory data

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