Accessing array elements in a vertx JsonObject - json

Question

Given the following io.vertx.core.json.JsonObject:
{
"111":[
{
"A":"a1",
},
{
"A":"a2",
},
{
"A":"a3",
}
],
"222":[
{
"A":"a10",
},
{
"A":"a20",
},
{
"A":"a30",
}
]
}
As the name of the outer elements which contain arrays (111 and 222) are not known in advance, what is the correct way to access the elements of each array, e.g.
{"A":"a1"}
Once the elements of the array are available as a collection, how can that collection be turned into an rxJava Observable.
Have tried the following:
List list = arrayElements.stream().collect(Collectors.toList());
Observable observable = Observable.fromIterable(list);
However, the issue is that each element in the stream is then represented as a java.util.LinkedHashMap.Entry, e.g. A=a1, whereas what is required is to retain the original Json representation.
Thanks

Answer 1

You can get object fields with JsonObject.fieldNames().
JsonArray is an Iterable<Object> because it may contain different types (objects, strings, ...etc). If you are confident that a JsonArray only contains JsonObject, you could cast the value.
Here's the result combined:
for (String fieldName : jsonObject.fieldNames()) {
JsonArray jsonArray = jsonObject.getJsonArray(fieldName);
Observable<JsonObject> observable = Observable
.fromIterable(jsonArray)
.map(JsonObject.class::cast);
System.out.println("fieldName = " + fieldName);
observable.subscribe(json -> System.out.println("json = " + json));
}