在Java中动态修改未知JSON的JsonNode [英] Modify JsonNode of unknown JSON dynamically in Java

问题描述

我正在尝试修改一个JSON（未知结构），其中JsonPath及其等效的XML Xpath是我所知道的。

I am trying to modify a JSON (of an unknown structure) where the JsonPath and its equivalent XML Xpath is known to me.

我已经厌倦了使用 com.jayway.jsonpath.JsonPath 同样的库。
JsonPath的问题是，它返回值但我无法修改目标节点。

I have tired using com.jayway.jsonpath.JsonPath library for the same. The problem with JsonPath is, it returns me the value but I am not able to modify the Target Node.

以下是我的相同代码片段

Follows is my code snippet for the same

JsonPath.read(jsonFile, jsonPath);
JsonPath.parse(jsonPath);
System.out.println("Author: "+JsonPath.read(jsonFile, jsonPath));

我尝试使用Jackson，如以前要求的排队，但它需要逐个节点遍历，如下所示

I tried using Jackson as mentioned in previously asked quetion, But it needs to be traversed node by node as follows

((ObjectNode) parent).put(fieldName, newValue);

由于结构未知，我无法做到。

which I cannot do due to unknown structure.

我已经尝试过给出问题的答案以递归方式解析JSON对象但它说如何解析不修改

I have tried the answer given to the question recursively parse JSON object but it says how to parse not modify

我需要执行以下操作

JsonNode root = mapper.readTree("Json in form of String");
((JsonNode)(root.get("JsonPath")).set("New Value");

有什么方法可以实现这个目标吗？

Is there any way in which this can be achieved?

推荐答案

JsonNode 对象是不可变的，所以你不能修改它们。你可以做的是用另一个替换 JsonNode 。强制转换为 ObjectNode 也需要公开所需的方法。首先找到要替换的节点的父节点：

JsonNode objects are immutable so you can't modify them. What you can do is replace a JsonNode with another one. A cast to ObjectNode is also required to expose the required methods. First find the parent of the node you want to replace :

JsonNode node = root.findParent("JsonPath");

然后使用其中任何一个用新方法替换它的2种方法：

Then use either of these 2 methods to replace it with a new one:

((ObjectNode) node).remove("JsonPath");           // remove current node
((ObjectNode) node).put("JsonPath", "New Value"); // add new one with new value

或

((ObjectNode) node).replace("JsonPath", new TextNode("New Value"));

这篇关于在Java中动态修改未知JSON的JsonNode的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！