GSON throwing "Expected BEGIN_OBJECT but was BEGIN_ARRAY"?
If GSON is throwing a JsonSyntaxException
with the message "Expected BEGIN_OBJECT but was BEGIN_ARRAY", it means that you are trying to parse a JSON array as if it were a JSON object.
To fix this error, you need to make sure that you are using the correct type to parse the JSON data. If the JSON data is an array, you should use a JsonArray
or a type that can be deserialized from a JSON array, such as a List
or an array. If the JSON data is an object, you should use a JsonObject
or a type that can be deserialized from a JSON object, such as a Java object annotated with GSON's @SerializedName
annotations.
Here's an example of how you can use a JsonArray
to parse a JSON array:
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
public class Main {
public static void main(String[] args) {
String json = "[{\"name\":\"John\",\"age\":30},{\"name\":\"Jane\",\"age\":25}]";
Gson gson = new Gson();
JsonArray array = gson.fromJson(json, JsonArray.class);
for (JsonElement element : array) {
Person person = gson.fromJson(element, Person.class);
System.out.println(person);
}
}
}
class Person {
private String name;
private int age;
// getters and setters
}
This code defines a Person
class with two fields: name
and age
. It also defines a main
method that creates a JSON array representing a list of people and uses a JsonArray
to parse the JSON array. The code then iterates over the JsonArray
and uses a Gson
object to parse each element of the array into a Person
object. The resulting Person
objects are then printed to the console.
I hope this helps! Let me know if you have any questions.