src/data/DebuggingJsonDeserializer.java


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package data;

import com.google.gson.GsonBuilder;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import java.lang.reflect.Type;

/**
 * Validates the deserialization of a JSON string. The main motivation of this
 * class is to print the property name of an object that throws an
 * IllegalStateException because a string was expected, but a different type got
 * returned.
 *
 * @author Peter Wu
 */
public class DebuggingJsonDeserializer extends ValidatingJsonDeserializer {

    private final Class overriddenClass;

    private DebuggingJsonDeserializer(Class overriddenClass) {
        this.overriddenClass = overriddenClass;
    }

    @Override
    public Object deserialize(JsonElement je, Type type,
            JsonDeserializationContext jdc) throws JsonParseException {
        checkObject("", je, overriddenClass);
        return null;
    }

    public static void tryValidate(String json, Class cls) {
        new GsonBuilder()
                .registerTypeAdapter(Dummy.class, new DebuggingJsonDeserializer(cls))
                .create()
                .fromJson(json, Dummy.class);
    }

    private class Dummy {
    }
}