Iterate items in ResponseBody and put them in a HashMap Spring Boot - json

Question

In a REST controller in Spring boot, I am trying to iterate the values in a RequestBody response and put some of them in a HashMap in a POST endpoint.
The JSON I am sending is of this structure:
{"name":"yogurt","vitaminA":6,"vitaminb12":5}
The endpoint looks like this so far:
#RequestMapping("/create")
public NutrientList createNUtrientList(#RequestBody NutrientList nutrientList) {
Map<String, Double> nutrientMap = new HashMap<String,Double>();
//get nutrient values, need help with this part
for()
//add values to map
NutrientList nl = new NutrientList(nutrientList.getName(), nutrientMap);
//will save to repository
return nl;
}
The NutrientList class looks like this:
public class NutrientList {
#Id
private ObjectId id;
#JsonProperty("name")
private String name;
#JsonProperty("nutrientMap")
Map <String,Double> nutrientMap = new HashMap<String,Double>();
public NutrientList() {}
public NutrientList(String name, Map<String, Double> nutrientMap) {
this.id = new ObjectId();
this.name = name;
this.nutrientMap = nutrientMap;
}
//setters and getters
}
The data is stored by separate nutrient in the database, it is not a map. I see the NutrientList class does not share the same structure, but is there any way I can get around this to be able to use a map without changing how it is stored in the database?
I need to use a map because there are many nutrients and I don't want to have separate variables for them. Thank you so much. Let me know if something is not clear.
EDIT:
I could alternately turn the csv where I got the data in the database from into JSON format with the map, but I have not found a tool online that gives me this flexibility.

Answer 1

If you have a list of valid keys, you could use the following:
private static final List<String> validKeys = Arrays.asList("vitaminA", "vitaminB" /* ... */);
#RequestMapping("/create")
public NutrientList createNutrientList(#RequestBody Map<String, Object> requestBody) {
Map<String, Double> nutrientMap = new HashMap<>();
for (String nutrient : requestBody.keySet()) {
if (validKeys.contains(nutrient) && requestBody.get(nutrient) instanceof Number) {
Number number = (Number) requestBody.get(nutrient);
nutrientMap.put(nutrient, number.doubleValue());
}
}
String name = (String) requestBody.get("name"); // maybe check if name exists and is really a string
return new NutrientList(name, nutrientMap);
}
If you want to use Java 8 Stream API you can try:
private static final List<String> validKeys = Arrays.asList("vitaminA", "vitaminB" /* ... */);
#RequestMapping("/create")
public NutrientList createNutrientList(#RequestBody Map<String, Object> requestBody) {
Map<String, Double> nutrientMap = requestBody.entrySet().stream()
.filter(e -> validKeys.contains(e.getKey()))
.filter(e -> e.getValue() instanceof Number)
.collect(Collectors.toMap(Map.Entry::getKey, e -> ((Number) e.getValue()).doubleValue()));
String name = Optional.ofNullable(requestBody.get("name"))
.filter(n -> n instanceof String)
.map(n -> (String) n)
.orElseThrow(IllegalArgumentException::new);
return new NutrientList(name, nutrientMap);
}
Hope that helps.