A location type adapter for Gson.

LocationAdapter.java

import com.google.gson.*;
import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.World;

import java.lang.reflect.Type;

/**
 * A gson adapter for {@link org.bukkit.Location}.
 * <p>
 * Licenced under GNU-GPLv3 to Minecraftly.
 * @author Cory Redmond &lt;ace@ac3-servers.eu&gt;
 */
public class LocationAdapter implements JsonDeserializer<Location>, JsonSerializer<Location> {

	public static final LocationAdapter INSTANCE = new LocationAdapter();

	@Override
	public Location deserialize( JsonElement json, Type type, JsonDeserializationContext jsonDeserializationContext ) throws JsonParseException {

		if ( !json.isJsonObject() ) {
			throw new JsonParseException( "not a JSON object" );
		}

		final JsonObject obj = (JsonObject) json;
		final JsonElement world = obj.get( "world" );
		final JsonElement x = obj.get( "x" );
		final JsonElement y = obj.get( "y" );
		final JsonElement z = obj.get( "z" );
		final JsonElement yaw = obj.get( "yaw" );
		final JsonElement pitch = obj.get( "pitch" );

		if ( world == null || x == null || y == null || z == null || yaw == null || pitch == null ) {
			throw new JsonParseException( "Malformed location json string!" );
		}

		if ( !world.isJsonPrimitive() || !((JsonPrimitive) world).isString() ) {
			throw new JsonParseException( "world is not a string" );
		}

		if ( !x.isJsonPrimitive() || !((JsonPrimitive) x).isNumber() ) {
			throw new JsonParseException( "x is not a number" );
		}

		if ( !y.isJsonPrimitive() || !((JsonPrimitive) y).isNumber() ) {
			throw new JsonParseException( "y is not a number" );
		}

		if ( !z.isJsonPrimitive() || !((JsonPrimitive) z).isNumber() ) {
			throw new JsonParseException( "z is not a number" );
		}

		if ( !yaw.isJsonPrimitive() || !((JsonPrimitive) yaw).isNumber() ) {
			throw new JsonParseException( "yaw is not a number" );
		}

		if ( !pitch.isJsonPrimitive() || !((JsonPrimitive) pitch).isNumber() ) {
			throw new JsonParseException( "pitch is not a number" );
		}

		World worldInstance = Bukkit.getWorld( world.getAsString() );
		if (worldInstance == null) {
			throw new IllegalArgumentException("Unknown/not loaded world");
		}

		return new Location( worldInstance, x.getAsDouble(), y.getAsDouble(), z.getAsDouble(), yaw.getAsFloat(), pitch.getAsFloat() );

	}

	@Override
	public JsonElement serialize( Location location, Type type, JsonSerializationContext jsonSerializationContext ) {

		final JsonObject obj = new JsonObject();
		obj.addProperty( "world", location.getWorld().getName() );
		obj.addProperty( "x", location.getX() );
		obj.addProperty( "y", location.getY() );
		obj.addProperty( "z", location.getZ() );
		obj.addProperty( "yaw", location.getYaw() );
		obj.addProperty( "pitch", location.getPitch() );
		return obj;

	}

}