Need to update the value in a Json node - json

Question

I have some arbitrary Json and I want to replace some of the text fields with objects. The text fields have a certain pattern, for example, say they start with a dollar sign $. I have no idea in advance what the keys are.
The object I want to replace it with is a Pojo probably a Map or List, which can be easily serialized to Json
For example
{
"key1" : "some value",
"key2" : "$replaceMe",
"key3" : {
"key4" : "more complex",
"key5" : "$andMe"
}
So after the replacement, the object would look something like this
{
"key1" : "some value",
"key2" : {},
"key3" : {
"key4" : "more complex",
"key5" : {}
}
where {} represents the new object that replaced the string that was previously there
I figured out several ways to traverse the tree, but can't figure out a good way to keep track of the objects to be replaced and how to replace them.

Answer 1

You can iterate over the JsonNode nodes of your json file checking the child nodes of every parent node : you can check if there are children nodes representing basic JSON String value with theJsonNode#isTextual method and if their text starts with the dollar sign like below:
ObjectMapper mapper = new ObjectMapper();
//with a generic parent jsnode and one child node of it
if (child.isTextual() && child.asText().startsWith("$")) {
//delete the old text value and create an empty objectnode
((ObjectNode)parent).set(fieldName, mapper.createObjectNode());
}
For the creation of an empty ObjectNode child you can use the ObjectMapper#createObjectNode method like I have done above.