Does anyone know how to decode a json string to List<Foo> in vert.x?
You can convert a string to object easily with Json.decodeValue(data, Foo.class); but I can't seem to figure out how to do so in case of lists.
So far I've gotten the data out with Json.decodeValue(data, List.class); but you can't really do anything with the result apart from print it out.
You'll have to declare a container object, but otherwise, it's quite simple:
// This is your Foo
public class MyObj {
public String key;
// Just for clarity
@Override
public String toString() {
return "MyObj{" +
"key='" + this.key + '\'' +
'}';
}
}
// This is the container
public class MyArray {
// Property is mandatory in this case
@JsonProperty("objs")
List<MyObj> objs;
}
And now the parsing
public static void main(final String[] args) {
// Your input is a JSON array, not a JSON object
final String input = "[{\"key\":\"a\"}, {\"key\":\"b\"}, {\"key\":\"c\"}]";
// We format it to be a JSON object, so we can parse it
final MyArray res = Json.decodeValue(String.format("{\"objs\":%s}", input), MyArray.class);
// Get your List out
System.out.println(res.objs);
}
Try this
List<Foo> fooList = Json.decodeValue(bodyAsString, new TypeReference<List<Foo>>(){});
TypeReference is Jackson reference for your information
The Json class use Jackson to decode the string.
I recommend you to use a Foo[] instead of a List. If you really need a List, you can easily create one "Arrays.asList(arr)".
Or you can use one of the examples on this site: http://www.baeldung.com/jackson-collection-array
Gson.fromJsonAPI for lists. stackoverflow.com/questions/18544133/…