Restore ExceptionFactory

buildSrc/src/main/kotlin/io/spine/dependency/build/Ksp.kt

@@ -35,7 +35,7 @@ import io.spine.dependency.Dependency
  */
 @Suppress("unused")
 object Ksp : Dependency() {
-    override val version = "2.3.0"
+    override val version = "2.3.6"
     val dogfoodingVersion = version
     override val group = "com.google.devtools.ksp"
 

buildSrc/src/main/kotlin/io/spine/dependency/local/Base.kt

@@ -33,8 +33,8 @@ package io.spine.dependency.local
  */
 @Suppress("ConstPropertyName", "unused")
 object Base {
-    const val version = "2.0.0-SNAPSHOT.385"
-    const val versionForBuildScript = "2.0.0-SNAPSHOT.385"
+    const val version = "2.0.0-SNAPSHOT.386"
+    const val versionForBuildScript = "2.0.0-SNAPSHOT.386"
     const val group = Spine.group
     private const val prefix = "spine"
     const val libModule = "$prefix-base"

buildSrc/src/main/kotlin/io/spine/dependency/local/Compiler.kt

@@ -72,7 +72,7 @@ object Compiler : Dependency() {
      * The version of the Compiler dependencies.
      */
     override val version: String
-    private const val fallbackVersion = "2.0.0-SNAPSHOT.040"
+    private const val fallbackVersion = "2.0.0-SNAPSHOT.041"
 
     /**
      * The distinct version of the Compiler used by other build tools.
@@ -81,7 +81,7 @@ object Compiler : Dependency() {
      * transitive dependencies, this is the version used to build the project itself.
      */
     val dogfoodingVersion: String
-    private const val fallbackDfVersion = "2.0.0-SNAPSHOT.039"
+    private const val fallbackDfVersion = "2.0.0-SNAPSHOT.041"
 
     /**
      * The artifact for the Compiler Gradle plugin.

buildSrc/src/main/kotlin/io/spine/dependency/local/ToolBase.kt

@@ -34,8 +34,8 @@ package io.spine.dependency.local
 @Suppress("ConstPropertyName", "unused")
 object ToolBase {
     const val group = Spine.toolsGroup
-    const val version = "2.0.0-SNAPSHOT.374"
-    const val dogfoodingVersion = "2.0.0-SNAPSHOT.374"
+    const val version = "2.0.0-SNAPSHOT.375"
+    const val dogfoodingVersion = "2.0.0-SNAPSHOT.375"
 
     const val lib = "$group:tool-base:$version"
     const val classicCodegen = "$group:classic-codegen:$version"

buildSrc/src/main/kotlin/io/spine/dependency/local/Validation.kt

@@ -36,7 +36,7 @@ object Validation {
     /**
      * The version of the Validation library artifacts.
      */
-    const val version = "2.0.0-SNAPSHOT.405"
+    const val version = "2.0.0-SNAPSHOT.406"
 
     /**
      * The last version of Validation compatible with ProtoData.

docs/content/docs/validation/01-getting-started/adding-to-build.md

@@ -90,7 +90,7 @@ Add the Validation plugin to the build.
 ```kotlin
 plugins {
     module
-    id("io.spine.validation") version "2.0.0-SNAPSHOT.406"
+    id("io.spine.validation") version "2.0.0-SNAPSHOT.407"
 }
 ```
 

jvm-runtime/src/main/java/io/spine/validation/ExceptionFactory.java

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2025, TeamDev. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.validation;
+
+import com.google.common.collect.ImmutableList;
+import com.google.protobuf.Message;
+import com.google.protobuf.ProtocolMessageEnum;
+import com.google.protobuf.Value;
+import io.spine.annotation.Internal;
+import io.spine.base.Error;
+import io.spine.protobuf.AnyPacker;
+import io.spine.type.MessageClass;
+
+import java.util.Map;
+
+import static java.lang.String.format;
+
+/**
+ * A helper class for building exceptions used to report invalid {@code Message}s,
+ * which have fields that violate validation constraint(s).
+ *
+ * @param <E>
+ *         the type of {@code Exception} to build
+ * @param <M>
+ *         the type of the {@code Message}, typically it would be a grouping interface such as
+ *         {@link io.spine.base.EventMessage} or {@link io.spine.base.CommandMessage}
+ * @param <C>
+ *         the type of the {@linkplain io.spine.type.MessageClass} of {@code |M|}
+ * @param <R>
+ *         the type of error code to use for error reporting; must be a Protobuf enum value
+ */
+@Internal
+public abstract class ExceptionFactory<E extends Exception,
+                                       M extends Message,
+                                       C extends MessageClass<?>,
+                                       R extends ProtocolMessageEnum> {
+
+    private final ImmutableList<ConstraintViolation> constraintViolations;
+    private final M message;
+
+    /**
+     * Creates an {@code ExceptionFactory} instance for a given message and
+     * constraint violations.
+     *
+     * @param message
+     *         an invalid event message
+     * @param violations
+     *         constraint violations for the event message
+     */
+    protected ExceptionFactory(M message, Iterable<ConstraintViolation> violations) {
+        this.constraintViolations = ImmutableList.copyOf(violations);
+        this.message = message;
+    }
+
+    /**
+     * Obtains a {@code MessageClass} for an invalid {@code Message}.
+     */
+    protected abstract C getMessageClass();
+
+    /**
+     * Obtains an error code to use for error reporting.
+     */
+    protected abstract R getErrorCode();
+
+    /**
+     * Obtains an error text to use for error reporting.
+     *
+     * <p>This text will also be used as a base for an exception message to generate.
+     */
+    protected abstract String getErrorText();
+
+    /**
+     * Obtains the {@code Message}-specific type attributes for error reporting.
+     */
+    protected abstract Map<String, Value> getMessageTypeAttribute(M message);
+
+    /**
+     * Defines the way to create an instance of exception basing on the source {@code Message},
+     * exception text, and a generated {@code Error}.
+     */
+    protected abstract E createException(String exceptionMsg, M message, Error error);
+
+    private String formatExceptionMessage() {
+        return format("%s. Message class: `%s`. %s",
+                      getErrorText(), getMessageClass(), violationsText());
+    }
+
+    private Error createError() {
+        var validationError = error();
+        var errorCode = getErrorCode();
+        var errorType = errorCode.getDescriptorForType()
+                                 .getFullName();
+        var errorText = errorText();
+
+        var error = Error.newBuilder()
+                .setType(errorType)
+                .setCode(errorCode.getNumber())
+                .setDetails(AnyPacker.pack(validationError))
+                .setMessage(errorText)
+                .putAllAttributes(getMessageTypeAttribute(message));
+        return error.build();
+    }
+
+    private ValidationError error() {
+        return ValidationError.newBuilder()
+                .addAllConstraintViolation(constraintViolations)
+                .build();
+    }
+
+    private String errorText() {
+        var errorTextTemplate = getErrorText();
+        var violationsText = violationsText();
+        return format("%s %s", errorTextTemplate, violationsText);
+    }
+
+    private String violationsText() {
+        return ViolationText.ofAll(constraintViolations);
+    }
+
+    /**
+     * Creates an exception instance for an invalid message which has fields that
+     * violate validation constraint(s).
+     */
+    public E newException() {
+        return createException(formatExceptionMessage(), message, createError());
+    }
+}

jvm-runtime/src/main/java/io/spine/validation/ValidationException.java

@@ -29,8 +29,8 @@
 import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.InlineMe;
 import io.spine.base.ErrorWithMessage;
-import io.spine.validation.diags.ViolationText;
 
+import java.io.Serial;
 import java.util.List;
 
 /**
@@ -39,6 +39,7 @@
 public class ValidationException
         extends RuntimeException implements ErrorWithMessage<ValidationError> {
 
+    @Serial
     private static final long serialVersionUID = 0L;
 
     /**

jvm-runtime/src/main/java/io/spine/validation/diags/ViolationText.java → jvm-runtime/src/main/java/io/spine/validation/ViolationText.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,13 +24,12 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-package io.spine.validation.diags;
+package io.spine.validation;
 
 import com.google.protobuf.Message;
 import io.spine.annotation.Internal;
 import io.spine.base.Field;
 import io.spine.option.OptionsProto;
-import io.spine.validation.ConstraintViolation;
 
 import java.util.Collection;