JsonVerification.java

package dmillerw.quadrum.common.lib;

import com.google.common.collect.Lists;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.annotations.SerializedName;
import dmillerw.quadrum.Quadrum;
import org.apache.logging.log4j.Level;

import java.io.File;
import java.lang.reflect.Field;
import java.util.List;
import java.util.Map;

/**
 * @author dmillerw
 */
public class JsonVerification {

    private static final String ERROR = "Failed to load %s. One or more required fields were missing %s";

    public static boolean verifyRequirements(File file, JsonObject jsonObject, Class<?> clazz) {
        List<String> keys = Lists.newArrayList();
        for (Map.Entry<String, JsonElement> entry : jsonObject.entrySet()) {
            keys.add(entry.getKey());
        }

        List<String> missingFields = Lists.newArrayList();

        for (Field field : clazz.getDeclaredFields()) {
            String name = field.getName();
            if (field.getAnnotation(SerializedName.class) != null) {
                name = field.getAnnotation(SerializedName.class).value();
            }

            if (field.getAnnotation(Required.class) != null && !keys.contains(name)) {
                missingFields.add(name);
            }
        }

        if (!missingFields.isEmpty()) {
            Quadrum.log(Level.WARN, ERROR, file.getName(), missingFields);
            return false;
        } else {
            return true;
        }
    }
}