Given the following .json file:
[
{
"name" : "New York",
"number" : "732921",
"center" : [
"latitude" : 38.895111,
"longitude" : -77.036667
]
},
{
"name" : "San Francisco",
"number" : "298732",
"center" : [
"latitude" : 37.783333,
"longitude" : -122.416667
]
}
]
I prepared two classes to represent the contained data:
public class Location {
public String name;
public int number;
public GeoPoint center;
}
...
public class GeoPoint {
public double latitude;
public double longitude;
}
In order to parse the content from the .json file I use Jackson 2.2.x and prepared the following method:
public static List<Location> getLocations(InputStream inputStream) {
ObjectMapper objectMapper = new ObjectMapper();
try {
TypeFactory typeFactory = objectMapper.getTypeFactory();
CollectionType collectionType = typeFactory.constructCollectionType(
List.class, Location.class);
return objectMapper.readValue(inputStream, collectionType);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
As long as I leave out the center
property all content can be parsed. However, when I try to parse the geo-coordinates I end up with the following error message:
com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of
com.example.GeoPoint out of START_ARRAY token at [Source: android.content.res.AssetManager$AssetInputStream@416a5850; line: 5, column: 25]
(through reference chain: com.example.Location["center"])
JsonMappingException: out of START_ARRAY token
exception is thrown by Jackson object mapper as it's expecting an Object {}
whereas it found an Array [{}]
in response.
This can be solved by replacing Object
with Object[]
in the argument for geForObject("url",Object[].class)
.
References: