Adding jackson support

README.md

@@ -42,6 +42,7 @@ Simple Builders is a Java [annotation processor](https://docs.oracle.com/en/java
 - **Collections Support**: Built-in support for collections and maps
 - **Annotation Preservation**: Validation annotations are automatically copied to builder methods
 - **With Interface Pattern**: Type-safe object modifications using generated With interfaces
+- **Jackson Support**: Supporting Jackson deserialization via `@JsonPOJOBuilder` and optional generation of `SimpleModule`s (one per package) (both need to be enabled)
 
 ## Requirements
 
@@ -268,7 +269,7 @@ The `With` interface provides type-safe setter methods that mirror the builder's
 
 Simple Builders provides extensive configuration options to customize the generated builder code. You can control:
 
-- Field setter generation (Supplier, Provider, Builder patterns)
+- Field setter generation (Supplier, Consumer, Builder patterns)
 - Conditional logic helpers
 - Access modifiers for builders and methods
 - Collection helper methods

core/src/main/java/org/javahelpers/simple/builders/core/annotations/SimpleBuilder.java

@@ -568,6 +568,55 @@
      */
     OptionState generateWithInterface() default OptionState.UNSET;
 
+    /**
+     * Add Jackson annotations to the generated builder class. <br>
+     * Adds {@code @JsonPOJOBuilder(withPrefix = "...")} to the builder class. The prefix matches
+     * the configured {@link #setterSuffix()}.
+     *
+     * <p>Example:
+     *
+     * <pre>{@code
+     * @JsonDeserialize(builder = PersonDtoBuilder.class)
+     * public class PersonDto { ... }
+     *
+     * // Generated:
+     * @JsonPOJOBuilder(withPrefix = "")
+     * public class PersonDtoBuilder { ... }
+     * }</pre>
+     *
+     * Default: DISABLED <br>
+     * Compiler option: -Asimplebuilder.usingJacksonDeserializerAnnotation
+     */
+    OptionState usingJacksonDeserializerAnnotation() default OptionState.UNSET;
+
+    /**
+     * Generate a Jackson SimpleModule containing registrations for all generated builders. <br>
+     * This module allows Jackson to use the generated builders for deserialization without needing
+     * to annotate the DTO classes.
+     *
+     * <p>The generated module class will be named {@code SimpleBuildersJacksonModule} (by default).
+     * By default, a module is generated in <b>each package</b> containing processed DTOs. To group
+     * all registrations into a single module, use {@link #jacksonModulePackage()}.
+     *
+     * <p>Default: DISABLED <br>
+     * Compiler option: -Asimplebuilder.generateJacksonModule
+     */
+    OptionState generateJacksonModule() default OptionState.UNSET;
+
+    /**
+     * Specifies the package name where the {@code SimpleBuildersJacksonModule} class will be
+     * generated. <br>
+     * This is useful to avoid split-package issues or to group all module registrations into a
+     * single module.
+     *
+     * <p>If not specified, a separate module will be generated in <b>each package</b> containing
+     * processed DTOs.
+     *
+     * <p>Default: "" (empty - generate one module per package) <br>
+     * Compiler option: -Asimplebuilder.jacksonModulePackage
+     */
+    String jacksonModulePackage() default "";
+
     // === Naming ===
     /**
      * Suffix to append to the DTO name to generate the builder class name. <br>

docs/CONFIGURATION.md

@@ -81,17 +81,25 @@ Create reusable configuration presets with custom template annotations:
 
 ```java
 @SimpleBuilder.Template(options = @SimpleBuilder.Options(
-    generateFieldSupplier = false,
-    generateFieldProvider = false,
-    generateBuilderProvider = false,
-    generateConditionalHelper = false,
-    generateVarArgsHelpers = false,
-    usingArrayListBuilder = false,
-    usingArrayListBuilderWithElementBuilders = false,
-    usingHashSetBuilder = false,
-    usingHashSetBuilderWithElementBuilders = false,
-    usingHashMapBuilder = false,
-    generateWithInterface = false
+    generateFieldSupplier = OptionState.DISABLED,
+    generateFieldConsumer = OptionState.DISABLED,
+    generateBuilderConsumer = OptionState.DISABLED,
+    generateConditionalHelper = OptionState.DISABLED,
+    generateVarArgsHelpers = OptionState.DISABLED,
+    generateStringFormatHelpers = OptionState.DISABLED,
+    generateAddToCollectionHelpers = OptionState.DISABLED,
+    generateUnboxedOptional = OptionState.DISABLED,
+    copyTypeAnnotations = OptionState.DISABLED,
+    usingArrayListBuilder = OptionState.DISABLED,
+    usingArrayListBuilderWithElementBuilders = OptionState.DISABLED,
+    usingHashSetBuilder = OptionState.DISABLED,
+    usingHashSetBuilderWithElementBuilders = OptionState.DISABLED,
+    usingHashMapBuilder = OptionState.DISABLED,
+    generateWithInterface = OptionState.DISABLED,
+    usingGeneratedAnnotation = OptionState.DISABLED,
+    usingBuilderImplementationAnnotation = OptionState.DISABLED,
+    implementsBuilderBase = OptionState.DISABLED,
+    usingJacksonDeserializerAnnotation = OptionState.DISABLED
 ))
 @Retention(RetentionPolicy.CLASS)
 @Target(ElementType.TYPE)
@@ -681,6 +689,93 @@ public class PersonDtoBuilder implements IBuilderBase<PersonDto> {
 
 ---
 
+#### `usingJacksonDeserializerAnnotation`
+
+**Default**: `DISABLED` | **Compiler Option**: `-Asimplebuilder.usingJacksonDeserializerAnnotation=ENABLED|DISABLED`
+
+Adds `@JsonPOJOBuilder` annotation to the builder class for Jackson deserialization support.
+
+**When ENABLED**:
+```java
+@JsonPOJOBuilder(withPrefix = "")
+public class PersonDtoBuilder {
+    // ...
+}
+```
+
+**When DISABLED**: No `@JsonPOJOBuilder` annotation.
+
+**Note**: This requires `com.fasterxml.jackson.core:jackson-databind` on the classpath during compilation. If missing, the annotation is skipped with a warning.
+
+---
+
+#### `generateJacksonModule`
+
+**Default**: `DISABLED` | **Compiler Option**: `-Asimplebuilder.generateJacksonModule=ENABLED|DISABLED`
+
+Generates a Jackson `SimpleModule` (named `SimpleBuildersJacksonModule`) that registers all generated builders via MixIns. This allows deserialization without annotating your DTOs with `@JsonDeserialize`.
+
+**Requirement**: You MUST also enable [`usingJacksonDeserializerAnnotation`](#usingjacksondeserializerannotation). If `generateJacksonModule` is enabled but `usingJacksonDeserializerAnnotation` is disabled, the processor will issue a warning and skip module generation.
+
+**When ENABLED**:
+1. The builder is generated as usual.
+2. A `SimpleBuildersJacksonModule` class is generated.
+3. The module registers a MixIn for the DTO that points to the Builder.
+
+**Package Name**:
+By default, a `SimpleBuildersJacksonModule` is generated in **each package** that contains DTOs configured for Jackson module generation. This ensures deterministic behavior.
+To specify a single fixed package name for all generated modules (grouping them into one), use the [`jacksonModulePackage`](#jacksonmodulepackage) option.
+
+**Generated Module Example**:
+```java
+package com.example.project.dto; // Generated in the same package as DTOs (by default)
+
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+public class SimpleBuildersJacksonModule extends SimpleModule {
+    public SimpleBuildersJacksonModule() {
+        setMixInAnnotation(PersonDto.class, PersonDtoMixin.class);
+    }
+
+    @JsonDeserialize(builder = PersonDtoBuilder.class)
+    private interface PersonDtoMixin {}
+}
+```
+
+**Usage**:
+```java
+ObjectMapper mapper = new ObjectMapper();
+
+// Register the module for your package
+// Note: If you have DTOs in multiple packages and use the default strategy,
+// you need to register the generated module for each package.
+mapper.registerModule(new com.example.project.dto.SimpleBuildersJacksonModule());
+
+PersonDto dto = mapper.readValue(json, PersonDto.class);
+```
+
+**Tip**: Use the [`jacksonModulePackage`](#jacksonmodulepackage) option to generate a single module for your entire project, making registration easier:
+`mapper.registerModule(new com.example.project.config.SimpleBuildersJacksonModule());`
+
+**Note**: This requires `com.fasterxml.jackson.core:jackson-databind` on the classpath.
+
+---
+
+#### `jacksonModulePackage`
+
+**Default**: `null` (uses package of each processed DTO) | **Compiler Option**: `-Asimplebuilder.jacksonModulePackage=com.your.package`
+
+Specifies the package name where the `SimpleBuildersJacksonModule` class will be generated.
+This is highly recommended to ensure deterministic output location and avoid split-package issues.
+
+**Note**: If not specified, a separate `SimpleBuildersJacksonModule` will be generated in **each package** containing processed DTOs.
+
+**Example**:
+`-Asimplebuilder.jacksonModulePackage=com.example.project.config`
+
+---
+
 ### Naming
 
 #### `builderSuffix`
@@ -722,16 +817,27 @@ public class PersonDto {
 Generate only essential builder methods:
 
 ```java
-@SimpleBuilder
-@SimpleBuilder.Options(
-    generateFieldSupplier = OptionState.DISABLED,
-    generateFieldConsumer = OptionState.DISABLED,
-    generateBuilderConsumer = OptionState.DISABLED,
-    generateConditionalHelper = OptionState.DISABLED,
-    generateVarArgsHelpers = OptionState.DISABLED,
-    usingArrayListBuilder = OptionState.DISABLED,
-    usingHashMapBuilder = OptionState.DISABLED,
-    generateWithInterface = OptionState.DISABLED
+@SimpleBuilder(
+    options = @SimpleBuilder.Options(
+        generateFieldSupplier = OptionState.DISABLED,
+        generateFieldConsumer = OptionState.DISABLED,
+        generateBuilderConsumer = OptionState.DISABLED,
+        generateConditionalHelper = OptionState.DISABLED,
+        generateVarArgsHelpers = OptionState.DISABLED,
+        generateStringFormatHelpers = OptionState.DISABLED,
+        generateAddToCollectionHelpers = OptionState.DISABLED,
+        generateUnboxedOptional = OptionState.DISABLED,
+        copyTypeAnnotations = OptionState.DISABLED,
+        usingArrayListBuilder = OptionState.DISABLED,
+        usingArrayListBuilderWithElementBuilders = OptionState.DISABLED,
+        usingHashSetBuilder = OptionState.DISABLED,
+        usingHashSetBuilderWithElementBuilders = OptionState.DISABLED,
+        usingHashMapBuilder = OptionState.DISABLED,
+        generateWithInterface = OptionState.DISABLED,
+        usingGeneratedAnnotation = OptionState.DISABLED,
+        usingBuilderImplementationAnnotation = OptionState.DISABLED,
+        implementsBuilderBase = OptionState.DISABLED,
+        usingJacksonDeserializerAnnotation = OptionState.DISABLED
 )
 public class MinimalDto {
     private String name;
@@ -770,11 +876,11 @@ Optimize for collection manipulation:
 ```java
 @SimpleBuilder
 @SimpleBuilder.Options(
-    generateVarArgsHelpers = true,
-    usingArrayListBuilder = true,
-    usingArrayListBuilderWithElementBuilders = true,
-    usingHashSetBuilder = true,
-    usingHashMapBuilder = true
+    generateVarArgsHelpers = OptionState.ENABLED,
+    usingArrayListBuilder = OptionState.ENABLED,
+    usingArrayListBuilderWithElementBuilders = OptionState.ENABLED,
+    usingHashSetBuilder = OptionState.ENABLED,
+    usingHashMapBuilder = OptionState.ENABLED
 )
 public class TeamDto {
     private List<String> memberNames;
@@ -802,17 +908,25 @@ Create a reusable template for lightweight builders:
 
 ```java
 @SimpleBuilder.Template(options = @SimpleBuilder.Options(
-    generateFieldSupplier = false,
-    generateFieldProvider = false,
-    generateBuilderProvider = false,
-    generateConditionalHelper = false,
-    generateVarArgsHelpers = false,
-    usingArrayListBuilder = false,
-    usingArrayListBuilderWithElementBuilders = false,
-    usingHashSetBuilder = false,
-    usingHashSetBuilderWithElementBuilders = false,
-    usingHashMapBuilder = false,
-    generateWithInterface = false
+    generateFieldSupplier = OptionState.DISABLED,
+    generateFieldConsumer = OptionState.DISABLED,
+    generateBuilderConsumer = OptionState.DISABLED,
+    generateConditionalHelper = OptionState.DISABLED,
+    generateVarArgsHelpers = OptionState.DISABLED,
+    generateStringFormatHelpers = OptionState.DISABLED,
+    generateAddToCollectionHelpers = OptionState.DISABLED,
+    generateUnboxedOptional = OptionState.DISABLED,
+    copyTypeAnnotations = OptionState.DISABLED,
+    usingArrayListBuilder = OptionState.DISABLED,
+    usingArrayListBuilderWithElementBuilders = OptionState.DISABLED,
+    usingHashSetBuilder = OptionState.DISABLED,
+    usingHashSetBuilderWithElementBuilders = OptionState.DISABLED,
+    usingHashMapBuilder = OptionState.DISABLED,
+    generateWithInterface = OptionState.DISABLED,
+    usingGeneratedAnnotation = OptionState.DISABLED,
+    usingBuilderImplementationAnnotation = OptionState.DISABLED,
+    implementsBuilderBase = OptionState.DISABLED,
+    usingJacksonDeserializerAnnotation = OptionState.DISABLED
 ))
 @Retention(RetentionPolicy.CLASS)
 @Target(ElementType.TYPE)
@@ -882,7 +996,7 @@ Configuration resolution follows these priority rules:
 // Global default: true
 
 @SimpleBuilder
-@SimpleBuilder.Options(generateFieldSupplier = true)  // Annotation wins!
+@SimpleBuilder.Options(generateFieldSupplier = OptionState.ENABLED)  // Annotation wins!
 public class Person {
     private String name;
 }
@@ -1115,6 +1229,7 @@ methodAccess = AccessModifier.PRIVATE
     implementsBuilderBase = OptionState.ENABLED,
     usingGeneratedAnnotation = OptionState.ENABLED,
     usingBuilderImplementationAnnotation = OptionState.ENABLED,
+    usingJacksonDeserializerAnnotation = OptionState.ENABLED,
 
     // Naming
     builderSuffix = "Builder",

example/pom.xml

@@ -17,6 +17,7 @@
     <code-format.version>2.25</code-format.version>
     <commons-lang.version>3.18.0</commons-lang.version>
     <junit-jupiter.version>5.11.4</junit-jupiter.version>
+    <jackson-databind.version>2.18.2</jackson-databind.version>
 
     <plugin.maven.compiler.version>3.13.0</plugin.maven.compiler.version>
     <plugin.maven.deploy.version>3.1.1</plugin.maven.deploy.version>
@@ -49,6 +50,13 @@
       <scope>test</scope>
     </dependency>
 
+    <!-- Jackson dependency required for testing Jackson integration features -->
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>${jackson-databind.version}</version>
+    </dependency>
+
   </dependencies>
 
 

example/src/main/java/org/javahelpers/simple/builders/example/ElementaryBuilder.java

@@ -40,14 +40,19 @@
             generateConditionalHelper = OptionState.DISABLED,
             generateVarArgsHelpers = OptionState.DISABLED,
             generateStringFormatHelpers = OptionState.DISABLED,
+            generateAddToCollectionHelpers = OptionState.DISABLED,
             generateUnboxedOptional = OptionState.DISABLED,
+            copyTypeAnnotations = OptionState.DISABLED,
             usingArrayListBuilder = OptionState.DISABLED,
             usingArrayListBuilderWithElementBuilders = OptionState.DISABLED,
             usingHashSetBuilder = OptionState.DISABLED,
             usingHashSetBuilderWithElementBuilders = OptionState.DISABLED,
             usingHashMapBuilder = OptionState.DISABLED,
             generateWithInterface = OptionState.DISABLED,
-            usingGeneratedAnnotation = OptionState.DISABLED))
+            usingGeneratedAnnotation = OptionState.DISABLED,
+            usingBuilderImplementationAnnotation = OptionState.DISABLED,
+            implementsBuilderBase = OptionState.DISABLED,
+            usingJacksonDeserializerAnnotation = OptionState.DISABLED))
 @Retention(RetentionPolicy.CLASS)
 @Target(ElementType.TYPE)
 public @interface ElementaryBuilder {}

example/src/main/java/org/javahelpers/simple/builders/example/JacksonIntegrationDto.java

@@ -0,0 +1,28 @@
+package org.javahelpers.simple.builders.example;
+
+import org.javahelpers.simple.builders.core.annotations.SimpleBuilder;
+import org.javahelpers.simple.builders.core.enums.OptionState;
+
+@SimpleBuilder(
+    options =
+        @SimpleBuilder.Options(
+            generateJacksonModule = OptionState.ENABLED,
+            usingJacksonDeserializerAnnotation = OptionState.ENABLED))
+public class JacksonIntegrationDto {
+    private final String name;
+    private final int age;
+
+    // Protected constructor - Jackson can't access this, but the builder can
+    protected JacksonIntegrationDto(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public String name() {
+        return name;
+    }
+
+    public int age() {
+        return age;
+    }
+}