Updated docs and implemented check for multiple versions and ids

Author: JohannesRabauer

docs/modules/ROOT/pages/features/ids.adoc

@@ -6,3 +6,14 @@
 * ``long`` / ``Long``
 * ``String``
 * ``UUID``
+
+Other generation types are currently not supported.
+
+== Composite keys
+
+It is possible to use **any class as https://jakarta.ee/specifications/persistence/3.2/apidocs/jakarta.persistence/jakarta/persistence/id[``@Id``]** but without any auto generation.
+Most importantly the used class **must have a valid ``hashCode``** since a ``HashMap`` is used to store and manage entities.
+
+{product-name} can also handle https://jakarta.ee/specifications/persistence/3.2/apidocs/jakarta.persistence/jakarta/persistence/embeddedid[``@EmbeddedId``] which results in the same behavior as ``@Id`` but the id-class must then implement ``Serializable``.
+
+Multiple Ids for a single entity and https://jakarta.ee/specifications/persistence/3.2/apidocs/jakarta.persistence/jakarta/persistence/idclass[``@IdClass``] are **not** supported.

spring-data-eclipse-store/src/main/java/software/xdev/spring/data/eclipse/store/exceptions/IdFieldFinalException.java renamed to spring-data-eclipse-store/src/main/java/software/xdev/spring/data/eclipse/store/exceptions/IdFieldException.java

@@ -15,9 +15,9 @@
  */
 package software.xdev.spring.data.eclipse.store.exceptions;
 
-public class IdFieldFinalException extends RuntimeException
+public class IdFieldException extends RuntimeException
 {
-	public IdFieldFinalException(final String message)
+	public IdFieldException(final String message)
 	{
 		super(message);
 	}

spring-data-eclipse-store/src/main/java/software/xdev/spring/data/eclipse/store/repository/support/AnnotatedFieldFinder.java

@@ -17,10 +17,17 @@
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
 
+import jakarta.persistence.EmbeddedId;
+import jakarta.persistence.Id;
+import jakarta.persistence.Version;
+
+import software.xdev.spring.data.eclipse.store.exceptions.IdFieldException;
+import software.xdev.spring.data.eclipse.store.exceptions.InvalidVersionException;
 import software.xdev.spring.data.eclipse.store.repository.access.AccessHelper;
 
 
@@ -39,13 +46,26 @@ private AnnotatedFieldFinder()
 	 */
 	public static Optional<Field> findIdField(final Class<?> domainClass)
 	{
-		return findAnnotatedField(
+		final List<Field> idFields = findAnnotatedFields(
 			domainClass,
 			List.of(
-				jakarta.persistence.Id.class,
+				Id.class,
 				org.springframework.data.annotation.Id.class,
-				jakarta.persistence.EmbeddedId.class)
+				EmbeddedId.class)
 		);
+		
+		if(idFields.isEmpty())
+		{
+			return Optional.empty();
+		}
+		else
+		{
+			if(idFields.size() > 1)
+			{
+				throw new IdFieldException("Only one id field is allowed");
+			}
+			return Optional.of(idFields.get(0));
+		}
 	}
 
 	/**
@@ -56,32 +76,46 @@ public static Optional<Field> findIdField(final Class<?> domainClass)
 	 */
 	public static Optional<Field> findVersionField(final Class<?> domainClass)
 	{
-		return findAnnotatedField(
+		final List<Field> versionFields = findAnnotatedFields(
 			domainClass,
-			List.of(jakarta.persistence.Version.class, org.springframework.data.annotation.Version.class)
+			List.of(Version.class, org.springframework.data.annotation.Version.class)
 		);
+		
+		if(versionFields.isEmpty())
+		{
+			return Optional.empty();
+		}
+		else
+		{
+			if(versionFields.size() > 1)
+			{
+				throw new InvalidVersionException("Only one version field is allowed");
+			}
+			return Optional.of(versionFields.get(0));
+		}
 	}
 
 	/**
 	 * Finds any field in a class with specified annotations. Finds this field recursively in the Hierarchy-tree.
 	 *
-	 * @return field with annotation. Is {@link Optional#empty()} if no field was found.
+	 * @return fields with annotation.
 	 */
-	public static Optional<Field> findAnnotatedField(
+	public static List<Field> findAnnotatedFields(
 		final Class<?> domainClass,
 		final Collection<Class<? extends Annotation>> annotations)
 	{
+		final ArrayList<Field> foundFields = new ArrayList<>();
 		final Collection<Field> classFields = AccessHelper.getInheritedPrivateFieldsByName(domainClass).values();
 		for(final Field currentField : classFields)
 		{
 			for(final Class<? extends Annotation> annotation : annotations)
 			{
 				if(currentField.getAnnotationsByType(annotation).length > 0)
 				{
-					return Optional.of(currentField);
+					foundFields.add(currentField);
 				}
 			}
 		}
-		return Optional.empty();
+		return foundFields;
 	}
 }

spring-data-eclipse-store/src/main/java/software/xdev/spring/data/eclipse/store/repository/support/copier/version/SimpleEntityVersionIncrementer.java

@@ -19,7 +19,7 @@
 import java.lang.reflect.Modifier;
 
 import software.xdev.spring.data.eclipse.store.exceptions.FieldAccessReflectionException;
-import software.xdev.spring.data.eclipse.store.exceptions.IdFieldFinalException;
+import software.xdev.spring.data.eclipse.store.exceptions.IdFieldException;
 import software.xdev.spring.data.eclipse.store.repository.access.modifier.FieldAccessModifier;
 import software.xdev.spring.data.eclipse.store.repository.support.copier.version.incrementer.VersionIncrementer;
 
@@ -43,7 +43,7 @@ private void checkIfVersionFieldIsFinal()
 		final int fieldModifiers = this.versionField.getModifiers();
 		if(Modifier.isFinal(fieldModifiers))
 		{
-			throw new IdFieldFinalException(String.format(
+			throw new IdFieldException(String.format(
 				"Field %s is final and cannot be modified. Version fields must not be final.",
 				this.versionField.getName()));
 		}

spring-data-eclipse-store/src/main/java/software/xdev/spring/data/eclipse/store/repository/support/id/SimpleIdSetter.java

@@ -20,7 +20,7 @@
 import java.util.function.Consumer;
 
 import software.xdev.spring.data.eclipse.store.exceptions.FieldAccessReflectionException;
-import software.xdev.spring.data.eclipse.store.exceptions.IdFieldFinalException;
+import software.xdev.spring.data.eclipse.store.exceptions.IdFieldException;
 import software.xdev.spring.data.eclipse.store.repository.access.modifier.FieldAccessModifier;
 import software.xdev.spring.data.eclipse.store.repository.support.id.strategy.IdFinder;
 
@@ -45,7 +45,7 @@ private void checkIfIdFieldIsFinal()
 		final int fieldModifiers = this.idField.getModifiers();
 		if(Modifier.isFinal(fieldModifiers))
 		{
-			throw new IdFieldFinalException(String.format(
+			throw new IdFieldException(String.format(
 				"Field %s is final and cannot be modified. ID fields must not be final.",
 				this.idField.getName()));
 		}