Jackson json deserialization mapping structure elasticsearch - jackson

Question

I need to parse a json file like this:
This is a sample mapping file for a collection of my elasticsearch engine server.
{
"mappings":
{
"documents" :
{
"_all" : {"enabled" : false},
"properties" :
{
"user_id" :
{
"type" : "string",
"index" : "not_analyzed",
"store": "no"
},
"mime_type" :
{
"type" : "string",
"index" : "not_analyzed",
"store": "no"
},
"source" :
{
"type" : "string",
"index": "not_analyzed",
"store": "no"
}
}
}
}
}
As you could be figuring out the schema is like that:
{
"mapping":
{
"**collection_name**":
{
...,
"properties":
{
"**property_name_1**":
{
"type": "string|int|date...",
...
},
"**property_name_2**":
{
"type": "string|int|date...",
...
},
...
}
}
}
}
And I would need to map this json to something like these classes:
public class Mapping {
private String collection;
private List<Property> properties;
public Mapping()
{
this.collection = null;
this.properties = new ArrayList<Property>();
}
...
}
public class Property
{
private String property;
private String type;
}
I've no idea how to do it with jackson.
Could you help me please? Thanks for all.

Answer 1

This is how you can do it with jackson:
ObjectMapper mapper = new ObjectMapper();
JsonNode rootNode;
try {
rootNode = mapper.readValue(jsonText, JsonNode.class);
JsonNode mappingsNode = rootNode.get("mappings");
String collectionName = mappingsNode.getFieldNames().next();
JsonNode collectionNode = mappingsNode.get(collectionName);
JsonNode propertiesNode = collectionNode.get("properties");
Iterator<JsonNode> elements = propertiesNode.getElements();
while (elements.hasNext()) {
JsonNode propertyNode = (JsonNode) elements.next();
// get properties one by one
}
} catch (IOException e) {
throw new RuntimeException("error while reading value", e);
}
Code is not completed by it presents the idea. Tested with jackson 1.8.0