diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityNotFoundException.kt b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityNotFoundException.kt
deleted file mode 100644
index e40eb45..0000000
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityNotFoundException.kt
+++ /dev/null
@@ -1,22 +0,0 @@
-package dev.fyloz.trial.colorrecipesexplorer.exception.model
-
-import dev.fyloz.trial.colorrecipesexplorer.exception.RestException
-import dev.fyloz.trial.colorrecipesexplorer.model.Model
-import org.springframework.http.HttpStatus
-import org.springframework.web.bind.annotation.ResponseStatus
-
-class EntityNotFoundException(
-    modelType: Class<out Model>,
-    val identifierType: IdentifierType,
-    val requestedId: Any
-) : ModelException(modelType)
-
-@ResponseStatus(HttpStatus.NOT_FOUND)
-class EntityNotFoundRestException(val value: Any) :
-    RestException("An entity could not be found with the given identifier", HttpStatus.NOT_FOUND) {
-
-    @Suppress("unused")
-    override fun buildBody(): RestExceptionBody = object : RestExceptionBody() {
-        val id = value
-    }
-}
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaNamedService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaNamedService.java
index 182130d..363996c 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaNamedService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaNamedService.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.NamedModel;
 import dev.fyloz.trial.colorrecipesexplorer.repository.NamedJpaRepository;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaService.java
index 8a8f1f6..51beda2 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/AbstractJavaService.java
@@ -3,8 +3,8 @@ package dev.fyloz.trial.colorrecipesexplorer.service;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import dev.fyloz.trial.colorrecipesexplorer.config.Preferences;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.NullIdentifierException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Model;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/CompanyJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/CompanyJavaService.java
index 71b2bcb..c88cf0f 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/CompanyJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/CompanyJavaService.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service.model;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityLinkedException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Company;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialJavaService.java
index 369bb22..482b2f0 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialJavaService.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service.model;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Material;
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialSaveDto;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialTypeJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialTypeJavaService.java
index 2477edc..0a93f52 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialTypeJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MaterialTypeJavaService.java
@@ -2,8 +2,8 @@ package dev.fyloz.trial.colorrecipesexplorer.service.model;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteDefaultMaterialTypeException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.CannotEditDefaultMaterialTypeException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialType;
 import dev.fyloz.trial.colorrecipesexplorer.model.dto.MaterialTypeEditorDto;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixJavaService.java
index 9e60e63..bb1ffb8 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixJavaService.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service.model;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.*;
 import dev.fyloz.trial.colorrecipesexplorer.model.dto.MixFormDto;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixTypeJavaService.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixTypeJavaService.java
index 92b72ef..dffd318 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixTypeJavaService.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/service/model/MixTypeJavaService.java
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.service.model;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Material;
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialType;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/OthersController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/OthersController.java
index 684fe40..80d2c2b 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/OthersController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/OthersController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
 import dev.fyloz.trial.colorrecipesexplorer.service.files.MarkdownFilesService;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/RecipeExplorerController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/RecipeExplorerController.java
index 1402a12..f1b236e 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/RecipeExplorerController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/RecipeExplorerController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Recipe;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.JSONResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/CompanyCreatorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/CompanyCreatorController.java
index 54edae7..370c9ba 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/CompanyCreatorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/CompanyCreatorController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.creators;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Company;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.java
index 65c902a..3bc8a42 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.java
@@ -1,7 +1,7 @@
 //package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.creators;
 //
 //import dev.fyloz.trial.colorrecipesexplorer.exception.SimdutException;
-//import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+//import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 //import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 //import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
 //import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseDataType;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.kt b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.kt
index ebc8a4b..80bbe88 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.kt
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialCreatorController.kt
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.creators
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.SimdutException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode
 import dev.fyloz.trial.colorrecipesexplorer.model.Material
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialSaveDto
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialTypeCreatorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialTypeCreatorController.java
index 6931697..64524d1 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialTypeCreatorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MaterialTypeCreatorController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.creators;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MixCreatorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MixCreatorController.java
index b55cdde..8b76a3d 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MixCreatorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/creators/MixCreatorController.java
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.creators;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.MixKt;
 import dev.fyloz.trial.colorrecipesexplorer.model.MixTypeKt;
 import dev.fyloz.trial.colorrecipesexplorer.model.Recipe;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialEditorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialEditorController.java
index 79de636..7e7fde1 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialEditorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialEditorController.java
@@ -1,8 +1,8 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.editors;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.SimdutException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseDataType;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialTypeEditorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialTypeEditorController.java
index 9f3d59d..a4f9cd2 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialTypeEditorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MaterialTypeEditorController.java
@@ -1,8 +1,8 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.editors;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.CannotEditDefaultMaterialTypeException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MixEditorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MixEditorController.java
index 92ced92..958bcd3 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MixEditorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/MixEditorController.java
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.editors;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Mix;
 import dev.fyloz.trial.colorrecipesexplorer.model.MixKt;
 import dev.fyloz.trial.colorrecipesexplorer.model.MixTypeKt;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/RecipeEditorController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/RecipeEditorController.java
index 66b52eb..4c5c30e 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/RecipeEditorController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/editors/RecipeEditorController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.editors;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Recipe;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/ImageFilesController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/ImageFilesController.java
index ded8fbe..d73b36f 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/ImageFilesController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/ImageFilesController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.files;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Recipe;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.JSONResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/SimdutFilesController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/SimdutFilesController.java
index d79236b..271757b 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/SimdutFilesController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/SimdutFilesController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.files;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.service.files.SimdutService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Profile;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/XlsExporterController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/XlsExporterController.java
index a420e4f..db097d7 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/XlsExporterController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/files/XlsExporterController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.files;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.service.files.XlsService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Profile;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/CompanyRemoverController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/CompanyRemoverController.java
index 24d9172..d1aee67 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/CompanyRemoverController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/CompanyRemoverController.java
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.removers;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityLinkedException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Company;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialRemoverController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialRemoverController.java
index e704505..6aec3e6 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialRemoverController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialRemoverController.java
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.removers;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityLinkedException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseDataType;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialTypeRemoverController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialTypeRemoverController.java
index 990a3ac..b7e6b1a 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialTypeRemoverController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MaterialTypeRemoverController.java
@@ -2,7 +2,7 @@ package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.removers;
 
 import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteDefaultMaterialTypeException;
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityLinkedException;
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseDataType;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MixRemoverController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MixRemoverController.java
index 227efbe..b99d58b 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MixRemoverController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/MixRemoverController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.removers;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Mix;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/RecipeRemoverController.java b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/RecipeRemoverController.java
index d52af7c..3cff967 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/RecipeRemoverController.java
+++ b/src/main/java/dev/fyloz/trial/colorrecipesexplorer/web/controller/thymeleaf/removers/RecipeRemoverController.java
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.web.controller.thymeleaf.removers;
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException;
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException;
 import dev.fyloz.trial.colorrecipesexplorer.model.Recipe;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ModelResponseBuilder;
 import dev.fyloz.trial.colorrecipesexplorer.web.response.ResponseCode;
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/config/WebSecurityConfig.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/config/WebSecurityConfig.kt
index 9863b35..8e08a7f 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/config/WebSecurityConfig.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/config/WebSecurityConfig.kt
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.config
 
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.Employee
 import dev.fyloz.trial.colorrecipesexplorer.model.EmployeeLoginRequest
 import dev.fyloz.trial.colorrecipesexplorer.model.EmployeePermission
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityAlreadyExistsException.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/Exception.kt
similarity index 53%
rename from src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityAlreadyExistsException.kt
rename to src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/Exception.kt
index 26232c5..1be48d6 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/model/EntityAlreadyExistsException.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/Exception.kt
@@ -1,9 +1,7 @@
-package dev.fyloz.trial.colorrecipesexplorer.exception.model
+package dev.fyloz.trial.colorrecipesexplorer.exception
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.RestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.model.ModelException
 import dev.fyloz.trial.colorrecipesexplorer.model.Model
-import org.springframework.http.HttpStatus
-import org.springframework.web.bind.annotation.ResponseStatus
 
 class EntityAlreadyExistsException(
     modelType: Class<out Model>,
@@ -26,12 +24,8 @@ class EntityAlreadyExistsException(
     )
 }
 
-@ResponseStatus(HttpStatus.CONFLICT)
-class EntityAlreadyExistsRestException(val value: Any) :
-    RestException("An entity with the given identifier already exists", HttpStatus.CONFLICT) {
-
-    @Suppress("unused")
-    override fun buildBody(): RestExceptionBody = object : RestExceptionBody() {
-        val id = value
-    }
-}
+class EntityNotFoundException(
+    modelType: Class<out Model>,
+    val identifierType: IdentifierType,
+    val requestedId: Any
+) : ModelException(modelType)
diff --git a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt
similarity index 57%
rename from src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt
rename to src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt
index 137afb9..6ac470e 100644
--- a/src/main/java/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/exception/RestException.kt
@@ -2,6 +2,7 @@ package dev.fyloz.trial.colorrecipesexplorer.exception
 
 import com.fasterxml.jackson.annotation.JsonProperty
 import dev.fyloz.trial.colorrecipesexplorer.exception.model.*
+import dev.fyloz.trial.colorrecipesexplorer.model.Model
 import org.springframework.context.annotation.Profile
 import org.springframework.http.HttpHeaders
 import org.springframework.http.HttpStatus
@@ -10,15 +11,51 @@ import org.springframework.validation.FieldError
 import org.springframework.web.bind.MethodArgumentNotValidException
 import org.springframework.web.bind.annotation.ControllerAdvice
 import org.springframework.web.bind.annotation.ExceptionHandler
+import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.context.request.WebRequest
 import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler
 
-abstract class RestException(val exceptionMessage: String, val httpStatus: HttpStatus) : RuntimeException(exceptionMessage) {
+abstract class RestException(val exceptionMessage: String, val httpStatus: HttpStatus) :
+    RuntimeException(exceptionMessage) {
     abstract fun buildBody(): RestExceptionBody
 
-    open inner class RestExceptionBody(val status: Int = httpStatus.value(), @JsonProperty("message") val message: String = exceptionMessage)
+    open inner class RestExceptionBody(
+        val status: Int = httpStatus.value(),
+        @JsonProperty("message") val message: String = exceptionMessage
+    )
 }
 
+@ResponseStatus(HttpStatus.CONFLICT)
+class EntityAlreadyExistsRestException(val value: Any) :
+    RestException("An entity with the given identifier already exists", HttpStatus.CONFLICT) {
+    @Suppress("unused")
+    override fun buildBody(): RestExceptionBody = object : RestExceptionBody() {
+        val id = value
+    }
+}
+
+@ResponseStatus(HttpStatus.NOT_FOUND)
+class EntityNotFoundRestException(val value: Any) :
+    RestException("An entity could not be found with the given identifier", HttpStatus.NOT_FOUND) {
+    @Suppress("unused")
+    override fun buildBody(): RestExceptionBody = object : RestExceptionBody() {
+        val id = value
+    }
+}
+
+@ResponseStatus(HttpStatus.CONFLICT)
+class CannotDeleteEntityRestException(val value: Long) :
+    RestException(
+        "The entity with the given identifier could not be deleted because it is required by other entities",
+        HttpStatus.CONFLICT
+    ) {
+    @Suppress("unused")
+    override fun buildBody(): RestExceptionBody = object : RestExceptionBody() {
+        val id = value
+    }
+}
+
+
 @ControllerAdvice
 @Profile("rest")
 class RestResponseEntityExceptionHandler : ResponseEntityExceptionHandler() {
@@ -32,7 +69,12 @@ class RestResponseEntityExceptionHandler : ResponseEntityExceptionHandler() {
         return handleExceptionInternal(exception, exception.buildBody(), HttpHeaders(), exception.httpStatus, request)
     }
 
-    override fun handleMethodArgumentNotValid(ex: MethodArgumentNotValidException, headers: HttpHeaders, status: HttpStatus, request: WebRequest): ResponseEntity<Any> {
+    override fun handleMethodArgumentNotValid(
+        ex: MethodArgumentNotValidException,
+        headers: HttpHeaders,
+        status: HttpStatus,
+        request: WebRequest
+    ): ResponseEntity<Any> {
         val errors = hashMapOf<String, String>()
         ex.bindingResult.allErrors.forEach {
             val fieldName = (it as FieldError).field
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/CompanyRepository.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/CompanyRepository.kt
index f07b1bd..c0a6a5a 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/CompanyRepository.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/CompanyRepository.kt
@@ -1,7 +1,18 @@
 package dev.fyloz.trial.colorrecipesexplorer.repository
 
 import dev.fyloz.trial.colorrecipesexplorer.model.Company
+import org.springframework.data.jpa.repository.Query
 import org.springframework.stereotype.Repository
 
 @Repository
-interface CompanyRepository : NamedJpaRepository<Company>
+interface CompanyRepository : NamedJpaRepository<Company> {
+    @Query(
+        """
+            select case when(count(r.id) > 0) then false else true end
+            from Company c
+            left join Recipe r on c.id = r.company.id
+            where c.id = :id
+        """
+    )
+    fun canBeDeleted(id: Long): Boolean
+}
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialRepository.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialRepository.kt
index 13a36bf..a678110 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialRepository.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialRepository.kt
@@ -2,6 +2,7 @@ package dev.fyloz.trial.colorrecipesexplorer.repository
 
 import dev.fyloz.trial.colorrecipesexplorer.model.Material
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialType
+import org.springframework.data.jpa.repository.Query
 import org.springframework.stereotype.Repository
 
 @Repository
@@ -11,4 +12,15 @@ interface MaterialRepository : NamedJpaRepository<Material> {
 
     /** Gets all the materials with the given [materialType]. */
     fun findAllByMaterialType(materialType: MaterialType): Collection<Material>
+
+    @Query(
+        """
+        select case when(count(mm.id) + count(mt.id) > 0) then false else true end
+        from Material m
+        left join MixMaterial mm on m.id = mm.material.id
+        left join MixType mt on m.id = mt.material.id
+        where m.id = :id
+    """
+    )
+    fun canBeDeleted(id: Long): Boolean
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialTypeRepository.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialTypeRepository.kt
index 14b2870..737500e 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialTypeRepository.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MaterialTypeRepository.kt
@@ -1,6 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.repository
 
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialType
+import org.springframework.data.jpa.repository.Query
 import org.springframework.stereotype.Repository
 
 @Repository
@@ -13,4 +14,14 @@ interface MaterialTypeRepository : NamedJpaRepository<MaterialType> {
 
     /** Gets the material type with the given [prefix]. */
     fun findByPrefix(prefix: String): MaterialType?
+
+    @Query(
+        """
+        select case when(count(m.id) > 0) then false else true end
+        from MaterialType t
+        left join Material m on t.id = m.materialType.id
+        where t.id = :id
+    """
+    )
+    fun canBeDeleted(id: Long): Boolean
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixRepository.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixRepository.kt
index 0c53732..082439e 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixRepository.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixRepository.kt
@@ -3,8 +3,19 @@ package dev.fyloz.trial.colorrecipesexplorer.repository
 import dev.fyloz.trial.colorrecipesexplorer.model.Mix
 import dev.fyloz.trial.colorrecipesexplorer.model.MixType
 import org.springframework.data.jpa.repository.JpaRepository
+import org.springframework.data.jpa.repository.Query
 
 interface MixRepository : JpaRepository<Mix, Long> {
     /** Finds all mixes with the given [mixType]. */
     fun findAllByMixType(mixType: MixType): Collection<Mix>
+
+    @Query(
+        """
+        select case when(count(mm.id) > 0) then false else true end
+        from Mix m
+        left join MixMaterial mm on m.mixType.material.id = mm.material.id
+        where m.id = :id
+    """
+    )
+    fun canBeDeleted(id: Long): Boolean
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixTypeRepository.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixTypeRepository.kt
index 0ae4ccc..87430d6 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixTypeRepository.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/repository/MixTypeRepository.kt
@@ -2,10 +2,21 @@ package dev.fyloz.trial.colorrecipesexplorer.repository
 
 import dev.fyloz.trial.colorrecipesexplorer.model.Material
 import dev.fyloz.trial.colorrecipesexplorer.model.MixType
+import org.springframework.data.jpa.repository.Query
 import org.springframework.stereotype.Repository
 
 @Repository
 interface MixTypeRepository : NamedJpaRepository<MixType> {
     /** Gets the mix type with the given [material]. */
     fun findByMaterial(material: Material): MixType?
+
+    @Query(
+        """
+        select case when(count(m.id) > 0) then false else true end
+        from MixType t
+        left join Mix m on t.id = m.mixType.id
+        where t.id = :id
+    """
+    )
+    fun canBeDeleted(id: Long): Boolean
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountService.kt
index 8240d29..d8aea18 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountService.kt
@@ -2,9 +2,9 @@ package dev.fyloz.trial.colorrecipesexplorer.service
 
 import dev.fyloz.trial.colorrecipesexplorer.config.blacklistedJwtTokens
 import dev.fyloz.trial.colorrecipesexplorer.config.defaultGroupCookieName
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.model.validation.or
 import dev.fyloz.trial.colorrecipesexplorer.repository.EmployeeGroupRepository
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyService.kt
index 9556cbd..80b5129 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyService.kt
@@ -1,5 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
+import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteEntityRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.Company
 import dev.fyloz.trial.colorrecipesexplorer.model.CompanySaveDto
 import dev.fyloz.trial.colorrecipesexplorer.model.CompanyUpdateDto
@@ -30,4 +31,9 @@ class CompanyServiceImpl(companyRepository: CompanyRepository, val recipeService
             )
         })
     }
+
+    override fun deleteById(id: Long) {
+        if (!repository.canBeDeleted(id)) throw CannotDeleteEntityRestException(id)
+        super.deleteById(id)
+    }
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialService.kt
index 8f97ccd..c72536d 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialService.kt
@@ -1,5 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
+import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteEntityRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MaterialRepository
 import dev.fyloz.trial.colorrecipesexplorer.service.files.SimdutService
@@ -90,4 +91,9 @@ class MaterialServiceImpl(
     private fun assertPersistedMaterial(material: Material) {
         Assert.notNull(material.name, "The persisted material with the id ${material.id} has a null name")
     }
+
+    override fun deleteById(id: Long) {
+        if (!repository.canBeDeleted(id)) throw CannotDeleteEntityRestException(id)
+        super.deleteById(id)
+    }
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeService.kt
index 81a4bc2..fd6741d 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeService.kt
@@ -1,8 +1,9 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import dev.fyloz.trial.colorrecipesexplorer.config.properties.MaterialTypeProperties
+import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteEntityRestException
 import dev.fyloz.trial.colorrecipesexplorer.exception.RestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialType
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialTypeSaveDto
 import dev.fyloz.trial.colorrecipesexplorer.model.MaterialTypeUpdateDto
@@ -73,11 +74,9 @@ class MaterialTypeServiceImpl(repository: MaterialTypeRepository, private val ma
         return super<AbstractExternalNamedModelService>.update(entity)
     }
 
-    override fun delete(entity: MaterialType) {
-        if (isUsedByMaterial(entity))
-            throw CannotDeleteUsedMaterialTypeRestException()
-
-        super.delete(entity)
+    override fun deleteById(id: Long) {
+        if (!repository.canBeDeleted(id)) throw CannotDeleteEntityRestException(id)
+        super.deleteById(id)
     }
 
     override fun saveSystemTypes(systemTypeProperties: Collection<MaterialTypeProperties.MaterialTypeProperty>) {
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixService.kt
index 386e65b..390674a 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixService.kt
@@ -1,5 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
+import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteEntityRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MixRepository
 import org.springframework.context.annotation.Lazy
@@ -110,4 +111,9 @@ class MixServiceImpl(
         recipeService.removeMix(entity)
         super.delete(entity)
     }
+
+    override fun deleteById(id: Long) {
+        if (!repository.canBeDeleted(id)) throw CannotDeleteEntityRestException(id)
+        super.deleteById(id)
+    }
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeService.kt
index aee1bb7..8911b23 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeService.kt
@@ -1,7 +1,8 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.CannotDeleteEntityRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MixTypeRepository
 import org.springframework.context.annotation.Lazy
@@ -53,4 +54,9 @@ class MixTypeServiceImpl(
             material.name = name
             material.materialType = materialType
         })
+
+    override fun deleteById(id: Long) {
+        if (!repository.canBeDeleted(id)) throw CannotDeleteEntityRestException(id)
+        super.deleteById(id)
+    }
 }
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeService.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeService.kt
index 210d7f4..0b05c70 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeService.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeService.kt
@@ -1,6 +1,6 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.model.validation.isNotNullAndNotBlank
 import dev.fyloz.trial.colorrecipesexplorer.model.validation.or
diff --git a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/Service.kt b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/Service.kt
index 1c6fc82..8e90de3 100644
--- a/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/Service.kt
+++ b/src/main/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/Service.kt
@@ -1,8 +1,8 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.EntityDto
 import dev.fyloz.trial.colorrecipesexplorer.model.Model
 import dev.fyloz.trial.colorrecipesexplorer.model.NamedModel
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AbstractServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AbstractServiceTest.kt
index ff0baf2..17d0ea3 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AbstractServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AbstractServiceTest.kt
@@ -1,8 +1,8 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.EntityDto
 import dev.fyloz.trial.colorrecipesexplorer.model.Model
 import dev.fyloz.trial.colorrecipesexplorer.model.NamedModel
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountsServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountsServiceTest.kt
index b862d96..ac9b44a 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountsServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/AccountsServiceTest.kt
@@ -2,8 +2,8 @@ package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
 import dev.fyloz.trial.colorrecipesexplorer.config.defaultGroupCookieName
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.EmployeeGroupRepository
 import dev.fyloz.trial.colorrecipesexplorer.repository.EmployeeRepository
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyServiceTest.kt
index 458f688..ebf45ce 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/CompanyServiceTest.kt
@@ -52,4 +52,10 @@ class CompanyServiceTest :
 
     override fun `update(dto) calls and returns update() with the created entity`() =
         withBaseUpdateDtoTest(entity, entityUpdateDto, service, any())
+
+    // delete()
+
+    override fun `deleteById() deletes the entity with the given id in the repository`() {
+        super.`deleteById() deletes the entity with the given id in the repository`()
+    }
 }
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialServiceTest.kt
index 24ed8a4..5856582 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialServiceTest.kt
@@ -1,12 +1,11 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MaterialRepository
 import dev.fyloz.trial.colorrecipesexplorer.service.files.SimdutService
 import org.junit.jupiter.api.AfterEach
-import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import org.springframework.mock.web.MockMultipartFile
@@ -191,6 +190,12 @@ class MaterialServiceTest :
         verify(simdutService).update(eq(mockSimdutFile), any())
     }
 
+    // delete()
+
+    override fun `deleteById() deletes the entity with the given id in the repository`() {
+        super.`deleteById() deletes the entity with the given id in the repository`()
+    }
+
     /** Helper function to replace collections.in because the id is not considered in the equals function of Material while Thymeleaf is supported. */
     private infix fun Collection<Material>.contains(material: Material): Boolean =
         any { it.id == material.id }
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeServiceTest.kt
index 802cdd3..10a2fee 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MaterialTypeServiceTest.kt
@@ -1,12 +1,11 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MaterialTypeRepository
 import org.junit.jupiter.api.AfterEach
-import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import kotlin.test.assertEquals
@@ -167,10 +166,7 @@ class MaterialTypeServiceTest :
         verify(repository).delete(entity)
     }
 
-    @Test
-    fun `delete() throws CannotDeleteUsedMaterialTypeRestException when the material type is in use`() {
-        doReturn(true).whenever(service).isUsedByMaterial(entity)
-
-        assertThrows<CannotDeleteUsedMaterialTypeRestException> { service.delete(entity) }
+    override fun `deleteById() deletes the entity with the given id in the repository`() {
+        super.`deleteById() deletes the entity with the given id in the repository`()
     }
 }
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixServiceTest.kt
index 728f344..43c1d13 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixServiceTest.kt
@@ -191,6 +191,12 @@ class MixServiceTest : AbstractExternalModelServiceTest<Mix, MixSaveDto, MixUpda
 
         verify(service).update(expected)
     }
+
+    // delete()
+
+    override fun `deleteById() deletes the entity with the given id in the repository`() {
+        super.`deleteById() deletes the entity with the given id in the repository`()
+    }
 }
 
 data class MixUpdateDtoTestScope(
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeServiceTest.kt
index b082889..36f9bc7 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/MixTypeServiceTest.kt
@@ -1,12 +1,11 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityAlreadyExistsRestException
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityAlreadyExistsRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.MixTypeRepository
 import org.junit.jupiter.api.AfterEach
-import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
 import kotlin.test.assertEquals
@@ -97,4 +96,11 @@ class MixTypeServiceTest : AbstractNamedModelServiceTest<MixType, MixTypeService
         assertEquals(materialType, found.material.materialType)
         assertTrue(found.material.isMixType)
     }
+
+    // delete()
+
+    override fun `deleteById() deletes the entity with the given id in the repository`() {
+        whenever(repository.canBeDeleted(any())).doReturn(true)
+        super.`deleteById() deletes the entity with the given id in the repository`()
+    }
 }
diff --git a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeServiceTest.kt b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeServiceTest.kt
index b03d4af..65a604c 100644
--- a/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeServiceTest.kt
+++ b/src/test/kotlin/dev/fyloz/trial/colorrecipesexplorer/service/RecipeServiceTest.kt
@@ -1,7 +1,7 @@
 package dev.fyloz.trial.colorrecipesexplorer.service
 
 import com.nhaarman.mockitokotlin2.*
-import dev.fyloz.trial.colorrecipesexplorer.exception.model.EntityNotFoundRestException
+import dev.fyloz.trial.colorrecipesexplorer.exception.EntityNotFoundRestException
 import dev.fyloz.trial.colorrecipesexplorer.model.*
 import dev.fyloz.trial.colorrecipesexplorer.repository.RecipeRepository
 import dev.fyloz.trial.colorrecipesexplorer.service.files.FilesService