Complete code-generation task

Add lombok annotations in User.java and Car.java.
Add serialization and deserialization Car object to JSON.
Add saving and extracting Car object data from file.

java-oop-ru/code-generation/src/main/java/exercise/App.java

@@ -5,5 +5,13 @@
 import java.nio.file.StandardOpenOption;
 
 // BEGIN
+public class App {
+    public static void save(Path filepath, Car car) throws Exception {
+        Files.writeString(filepath, car.serialize(), StandardOpenOption.CREATE);
+    }
 
+    public static Car extract(Path filepath) throws Exception {
+        return Car.unserialize(Files.readString(filepath));
+    }
+}
 // END

java-oop-ru/code-generation/src/main/java/exercise/Car.java

@@ -4,7 +4,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 // BEGIN
-
+@Value
 // END
 class Car {
     int id;
@@ -14,6 +14,12 @@ class Car {
     User owner;
 
     // BEGIN
-
+    public String serialize() throws Exception {
+        return new ObjectMapper().writeValueAsString(this);
+    }
+
+    public static Car unserialize(String json) throws Exception {
+        return new ObjectMapper().readValue(json, Car.class);
+    }
     // END
 }

java-oop-ru/code-generation/src/main/java/exercise/User.java

@@ -3,7 +3,7 @@
 import lombok.Value;
 
 // BEGIN
-
+@Value
 // END
 class User {
     int id;