如何对嵌套的 JSON 数组进行排序?

本文介绍了如何对嵌套的 JSON 数组进行排序?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

如何对嵌套的 JSON 数组进行排序?就像下面的 JSON...

How can i sort Nested JSON Array? Like for a JSON below...

{ "id":"rtmc05.lax.someabc", "name":"rtmc05.lax.someabc", "tenants":[{ "id":"rtmc", "name":"rtmc" },{ "id":"hrs", "name":"hrs" },{ "id":"amotelbe1", "name":"amotelbe" },{ "id":"cds", "name":"cds" },{ "id":"idx-server", "name":"idx-server", "tenants":[{ "id":"amotelbe", "name":"amotelbe", "tenants":[{ "id":"amotelui", "name":"amotelui" }] }] }] }

推荐答案

您的问题隐含了一些部分，并且不清楚您在哪里遇到问题:

There's a few parts implicit to your question, and it's not clear where you're having trouble:

如何获取 JSON 字符串并从中生成可用的 Java 对象.(我假设是 Java，而不是 JavaScript，因为您已经用java"标记了您的问题.)

这些物品制作完成后如何分类?

您如何处理嵌套部分的排序?(在您的示例中，idx-server"有子租户.)

不确定您在这方面的哪些部分遇到了问题，所以这里有针对这三个部分的一些注意事项.

Not sure exactly which parts of this you're having trouble with, so here's some notes for all three.

第 1 部分:获取 Java 对象

Part 1: Getting Java objects

我同意另一个人的看法，Jackson 是一个很好的 JSON 解析器.这里有几行代码可以用来解析一些 JSON:

I agree with the other guy that Jackson is a good JSON parser to use. Here's a couple lines of code you could use to parse some JSON:

String jsonString = "..."; // Load this in whatever way makes sense for you ObjectMapper mapper = new ObjectMapper(); Map<String,Object> parsedJson = mapper.readValue(jsonString, Map.class);

如果您的 JSON 字符串真的很大，那么您可以使用其他 readValue 重载来避免将整个字符串读入内存.

If your JSON string is really huge, then there are other readValue overloads that you can use to avoid reading the whole String into memory.

第 2 部分:对 Java 对象进行排序

Part 2: Sorting Java objects

一旦你得到解析的 JSON，排序就只是调用 Collections.sort(...)，传入租户 数组.另外，您需要编写一个 Comparator定义您想要的排序.例如，这是一个按名称排序的比较器:

Once you've got the parsed JSON, sorting is just a matter of calling Collections.sort(...), passing in the tenants array. Plus you'll need to write a Comparator that defines the ordering that you want. For example, here's a comparator that sorts by name:

public class NameComparator implements Comparator<Map<String,Object>> { public int compare(Map<String,Object> o1, Map<String,Object> o2) { String name1 = (String) o1.get("name"); String name2 = (String) o2.get("name"); return name1pareTo(name2); } }

然后你得到租户数组(Jackson 将它们变成 ArrayList 对象)并调用 Collections.sort(...).例如，

Then you get the tenants array out (Jackson makes them into ArrayList objects) and call Collections.sort(...). For example,

List<Map<String,Object>> tenants = (List<Map<String,Object>>) parsedJson.get("tenants"); Collections.sort(tenants, new NameComparator());

第 3 部分:处理嵌套

Part 3: Handling the nesting

最清晰的方法是添加一些额外的代码来遍历您的 JSON 以查找具有租户数组的任何对象，并对其进行排序.例如，这是一个应该执行此操作的递归函数:

The clearest way to do this is to add some extra code to walk through your JSON looking for any object with a tenants array, and sort it. For example, here's a recursive function that should do it:

public static void recursiveSortTenants(Map<String,Object> jsonObject) { List<Map<String,Object>> tenants = (List<Map<String,Object>>) jsonObject.get("tenants"); if (tenants != null) { Collections.sort(tenants, new NameComparator()); // For each tenant, see if it has sub-tenants. If so, // call this function again to sort them. for (Map<String,Object> tenant : tenants) { if (tenants.containsKey("tenants")) { recursiveSortTenants(tenant); } } } }

希望这会有所帮助！