How automatically parse response String into Map using RestTemplate - json

Question

I'm using RestTemplate to retrieve list of issues from Jira. As response I get String with lots of fields, some of them are arrays. Request looks like:
ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.GET, entity, String.class);
Response string looks like:
{
"expand": "schema,names",
"total": 12,
"issues": [
{
"id": "32",
"key": "TEST-1",
"fields": {
"fixVersions": [
{
"description": "",
"releaseDate": "2017-04-02"
}
]
},
{
"id": "32",
"key": "TEST-2",
"fields": {
"fixVersions": [
{
"description": "",
"releaseDate": "2017-04-01"
}
]
}
]
}
Is it possible to convert this String into Map, where Object could be String or List of Map or something like this, without defining appropriate objects. As result, I'd like to have possibility to access description by: response.getIssues().get(0).getFields().getFixVersion().get(0).getDescription()
In such occasion, defining chain of specific objects looks too cumbersome.

Answer 1

You can create your own POJO classes which corresponds to the structure of the response JSON.
Based on the json that you have shared, you can have a class structure like this :
public class Response {
private String expand;
private String total;
private List<Issues> issues;
}
public class Issues {
private String id;
private String key;
private Map<String, List<FixVersions> fields;
}
public class FixVersions {
private String description;
private String releaseData;
}
Your GET call will change to the following :
ResponseEntity response = restTemplate.exchange(url,
HttpMethod.GET, entity, Response.class);
P.S. - All the fields in the POJO class must have their getters and
setters as well.