Added automatic serializer for custom classes based on reflections

Author: mikigal

README.MD

@@ -10,6 +10,7 @@ Config API for Bukkit 1.8 - 1.17 based on dynamic proxies
  - Automatic update of config's file after add new methods to it's interface
  - Support for setting new values to config
  - System of serializers for custom objects (e.g. ItemStack, Location)
+ - Automatic serialization of custom objects based on reflections (mainly for simple DAO/DTO objects)
  - Support of comments in YAML config
  - Automatic translation of `&` based colors
 
@@ -20,7 +21,7 @@ maven {
     url = 'https://repo.mikigal.pl/releases'
 }
 
-compile group: 'pl.mikigal', name: 'ConfigAPI', version: '1.1.6'
+compile group: 'pl.mikigal', name: 'ConfigAPI', version: '1.1.7'
 ```
 
 #### Maven
@@ -33,7 +34,7 @@ compile group: 'pl.mikigal', name: 'ConfigAPI', version: '1.1.6'
 <dependency>
     <groupId>pl.mikigal</groupId>
     <artifactId>ConfigAPI</artifactId>
-    <version>1.1.6</version>
+    <version>1.1.7</version>
     <scope>compile</scope>
 </dependency>
 ```
@@ -160,7 +161,41 @@ award:
  - ShapedRecipe
  - UUID
 
+#### Automatic serializing of custom objects
+If you have some simple DAO/DTO object you can serialize it without writing custom serializer!
+
+```java
+public class User implements Serializable { // It must implement Serializable interface
+	private String username;
+	private int kills;
+	private transient String temporary; // Transient fields will not be serialized!
+
+	public User() { // It MUST have no-args constructor!
+        
+    }
+
+	public User(String username, int kills, String temporary) {
+		this.username = username;
+		this.kills = kills;
+		this.temporary = temporary;
+    }
+	
+	// Getters and setters...
+}
+
+@ConfigName("config")
+public interface MyConfig extends Config {
+	
+	void setUser(User user);
+	
+	default User getTest() {
+		return new User("mikigal", 1, "some text");
+    }
+}
+```
+
 #### You can also make your own serializers
+For more advanced objects you can make your own serializer
 ```java
 public class PotionEffectSerializer extends Serializer<PotionEffect> {
 
@@ -198,3 +233,4 @@ public class TestPlugin extends JavaPlugin {
 
     }
 }
+

build.gradle

@@ -4,7 +4,7 @@ plugins {
 }
 
 group 'pl.mikigal'
-version '1.1.6'
+version '1.1.7'
 
 publishing {
     repositories {

src/main/java/pl/mikigal/config/ConfigInvocationHandler.java

@@ -217,6 +217,10 @@ private boolean updateConfigFile() {
 				throw new InvalidConfigException("Found non getter/setter method (name: " + name + ") in " + clazz.getCanonicalName());
 			}
 
+			if (method.getParameters().length != 0) {
+				throw new InvalidConfigException("Found method with parameters (name: " + name + ") in " + clazz.getCanonicalName());
+			}
+
 			if (!method.isDefault() || this.configuration.contains(this.getConfigPath(method))) {
 				continue;
 			}

src/main/java/pl/mikigal/config/serializer/Serializers.java

@@ -9,7 +9,9 @@
 import pl.mikigal.config.serializer.universal.UniversalArraySerializer;
 import pl.mikigal.config.serializer.universal.UniversalCollectionSerializer;
 import pl.mikigal.config.serializer.universal.UniversalMapSerializer;
+import pl.mikigal.config.serializer.universal.UniversalObjectSerializer;
 
+import java.io.Serializable;
 import java.util.*;
 
 /**
@@ -22,7 +24,7 @@ public class Serializers {
 	/**
 	 * Map of registered serializers
 	 */
-	public static final Map<Class<?>, Serializer<?>> SERIALIZERS = new HashMap<>();
+	public static final Map<Class<?>, Serializer<?>> SERIALIZERS = new LinkedHashMap<>();
 
 	static {
 		register(ItemStack.class, new ItemStackSerializer());
@@ -34,6 +36,7 @@ public class Serializers {
 		register(Object[].class, new UniversalArraySerializer());
 		register(Collection.class, new UniversalCollectionSerializer());
 		register(Map.class, new UniversalMapSerializer());
+		register(Serializable.class, new UniversalObjectSerializer());
 	}
 
 	/**

src/main/java/pl/mikigal/config/serializer/universal/UniversalObjectSerializer.java

@@ -0,0 +1,92 @@
+package pl.mikigal.config.serializer.universal;
+
+import pl.mikigal.config.BukkitConfiguration;
+import pl.mikigal.config.serializer.Serializer;
+
+import java.io.Serializable;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+/**
+ * Helper built-in serializer for custom objects which implemenet Serializable interface.
+ * It uses reflections to serialize all fields from given Object, which are not transient and static.
+ * Class must have default constructor (no-args).
+ * @see Serializer
+ * @see Serializable
+ * @since 1.1.7
+ * @author Mikołaj Gałązka
+ */
+public class UniversalObjectSerializer extends Serializer<Serializable> {
+
+	@Override
+	protected void saveObject(String path, Serializable object, BukkitConfiguration configuration) {
+		this.validateDefaultConstructor(object);
+
+		try {
+			for (Field field : object.getClass().getDeclaredFields()) {
+				if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())) {
+					continue;
+				}
+
+				field.setAccessible(true);
+				Object value = field.get(object);
+
+				try {
+					configuration.set(path + "." + configuration.getNameStyle().format(field.getName()), value);
+				} catch (Exception e) {
+					throw new RuntimeException("An error occurred while serializing field '" + field.getName() + "' from class '" + object.getClass().getName() + "'", e);
+				}
+			}
+
+			configuration.set(path + "." + configuration.getNameStyle().format("type"), object.getClass().getName());
+		} catch (IllegalAccessException e) {
+			throw new RuntimeException("An error occurred while serializing class '" + object.getClass().getName() + "'", e);
+		}
+	}
+
+	@Override
+	public Serializable deserialize(String path, BukkitConfiguration configuration) {
+		String classPath = configuration.getString(path + "." + configuration.getNameStyle().format("type"));
+		Class<?> clazz;
+
+		try {
+			clazz = Class.forName(classPath);
+		} catch (ClassNotFoundException e) {
+			throw new RuntimeException("An error occurred while deserializing class '" + classPath + "'", e);
+		}
+
+		if (!Serializable.class.isAssignableFrom(clazz)) {
+			throw new RuntimeException("Class " + classPath + " does not implements Serializable");
+		}
+
+		Serializable instance;
+		try {
+			 instance = (Serializable) clazz.newInstance();
+		} catch (InstantiationException | IllegalAccessException e) {
+			throw new RuntimeException("Could not create instance of class (" + classPath + ") with default constructor", e);
+		}
+
+		try {
+			for (Field field : clazz.getDeclaredFields()) {
+				if (Modifier.isStatic(field.getModifiers()) || Modifier.isTransient(field.getModifiers())) {
+					continue;
+				}
+
+				field.setAccessible(true);
+				field.set(instance, configuration.get(path + "." + configuration.getNameStyle().format(field.getName())));
+			}
+		} catch (IllegalAccessException e) {
+			throw new RuntimeException("Could not deserialize " + classPath, e);
+		}
+
+		return instance;
+	}
+
+	private void validateDefaultConstructor(Object object) {
+		try {
+			object.getClass().getConstructor();
+		} catch (NoSuchMethodException e) {
+			throw new IllegalArgumentException("Class " + object.getClass().getName() + " does not have a default constructor");
+		}
+	}
+}

src/main/java/pl/mikigal/config/style/NameStyle.java

@@ -51,6 +51,6 @@ public enum NameStyle {
 	 * @return name of field in config
 	 */
 	public String format(String methodName) {
-		return CaseFormat.UPPER_CAMEL.to(this.caseFormat, methodName.replace("get", "").replace("set", ""));
+		return caseFormat.to(this.caseFormat, methodName.replace("get", "").replace("set", ""));
 	}
 }