MapStruct and Lombok not working together

Tech Stack being used :

Java 8 MapStruct : 1.2.0.Final Lombok: 1.16.18 IDE: IntelliJ - Lombok Plugin already installed

• Initially, I faced issues when I removed getters and setters and added @Getter and @Setter annotation, mapstruct is not able to find the property and says: Unknown property "id" in result type com.vg.once.dto.OneDto. Did you mean "null"?
• I came to know that Lombok 1.16.14 or newer along with MapStruct 1.2.0.Beta1 or newer are compatible and can work together, but my versions are newer then the desired still the issue is arising.
• One more solution that I have already tried is running Lombok's Delombok plugin, but still, the same issue is arising.

Below are the project files :

The Entity Object: One.java:

import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class One {
	
	private int id;
    private Integer version;
    private int projectId;
    private String title;
    private String code;
    private int sortOrder;
        
}

The DTO Object: OneDTO.java :

import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class OneDto {
	
	private int id;
    private Integer version;
    private int projectId;
    private String title;
    private String code;
    private int sortOrder;
    
}

Mapper Class : OneMapper.java

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;

import com.vg.once.dto.OneDto;
import com.vg.once.entity.One;

@Mapper
public interface OneMapper {
	
	@Mapping(target="id", source="one.id")
	OneDto createOne (One one);

}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.vg</groupId>
  <artifactId>mapstruct</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>Mapstruct-test</name>

	<properties>
		<java.version>1.8</java.version>
        <org.mapstruct.version>1.2.0.Final</org.mapstruct.version>
        <org.projectlombok.version>1.16.18</org.projectlombok.version>
    </properties>
         
	<dependencies>
		<dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${org.projectlombok.version}</version>
            <scope>provided</scope>
        </dependency>
   		<dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-jdk8</artifactId>
            <version>${org.mapstruct.version}</version>
        </dependency>
	</dependencies>

 	<build>
		<plugins> 
		 <plugin>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok-maven-plugin</artifactId>
                <version>1.16.18.1</version>
                <executions>
                    <execution>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>delombok</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <sourceDirectory>src/main/java</sourceDirectory>
                    <addOutputDirectory>false</addOutputDirectory>
                    <outputDirectory>${project.build.directory}/delombok</outputDirectory>
                    <encoding>UTF-8</encoding>
                    <skip>false</skip>
                    <verbose>false</verbose>
                </configuration>
            </plugin>       
        	<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.6.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.mapstruct</groupId>
                            <artifactId>mapstruct-processor</artifactId>
                            <version>${org.mapstruct.version}</version>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>
        </plugins>
    </build>  
</project>

Build Trace:

[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Mapstruct-test 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- lombok-maven-plugin:1.16.18.1:delombok (default) @ mapstruct ---
[INFO] Delombok complete.
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ mapstruct ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.6.1:compile (default-compile) @ mapstruct ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding UTF-8, i.e. build is platform dependent!
[INFO] Compiling 5 source files to /home/vivekgupta/Documents/workspaces/mapstruct-test/mapstruct/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/vivekgupta/Documents/workspaces/mapstruct-test/mapstruct/src/main/java/com/vg/once/mapper/OneMapper.java:[12,9] Unknown property "id" in result type com.vg.once.dto.OneDto. Did you mean "null"?
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.637 s
[INFO] Finished at: 2017-12-06T19:23:53+05:30
[INFO] Final Memory: 19M/235M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.1:compile (default-compile) on project mapstruct: Compilation failure
[ERROR] /home/vivekgupta/Documents/workspaces/mapstruct-test/mapstruct/src/main/java/com/vg/once/mapper/OneMapper.java:[12,9] Unknown property "id" in result type com.vg.once.dto.OneDto. Did you mean "null"?
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

please share how can i get this working using both Lombok and MapStruct together?

The reason why it does not work is because Maven only uses the MapStruct processor and not the Lombok one. The annotationProcessorPaths tells maven which processors it should use.

The delombok does nothing as you are ending up with 2 files per class and I think that the maven compiler does not see them.

You have 2 options:

Option 1: Add the lombok dependency in the annotationProcessorPaths

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.6.1</version>
    <configuration>
        <source>${java.version}</source>
        <target>${java.version}</target>
        <annotationProcessorPaths>
            <path>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${org.projectlombok.version}</version>
            </path>
            <!-- This is needed when using Lombok 1.18.16 and above -->
            <path>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok-mapstruct-binding</artifactId>
                <version>0.2.0</version>
            </path>
            <!-- Mapstruct should follow the lombok path(s) -->
            <path>
                <groupId>org.mapstruct</groupId>
                <artifactId>mapstruct-processor</artifactId>
                <version>${org.mapstruct.version}</version>
            </path>
        </annotationProcessorPaths>
    </configuration>
</plugin>

Option 2:

Add the mapstruct-processor dependency to your dependencies and remove the annotationProcessorPaths. This way the maven compiler will pick up all the annotation processors that are in your dependencies.

I would advise in using Option 1, as with that you can be certain that you are not using some MapStruct transitive dependencies and internal classes in your code.

Edit:

To make sure that the IntelliJ annotation processing also works you will have to add the mapstruct-processor as a provided dependency due to IDEA-150621. IntelliJ in the moment does not use the annotationProcessorPaths from Maven to configure the project correctly.

Edit 2:

Add information and comment about lombok-mapstruct-binding needed from Lombok 1.18.16.

Just in case if somebody is looking for how to configure it using Gradle:

dependencies {

   // Lombok
   compileOnly 'org.projectlombok:lombok:1.18.2'
   annotationProcessor 'org.projectlombok:lombok:1.18.2'

   // MapStruct
   compileOnly 'org.mapstruct:mapstruct-jdk8:1.2.0.Final'
   annotationProcessor 'org.mapstruct:mapstruct-processor:1.2.0.Final'

}

For me solution was realy simple.

The order of the processors was important.

In my case mapstruct processor was defined before lombok processor. In case with bad order mapstruct does not generate mappings, just create instance of result class (i saw that in generated implementation).

My plugin configuration with right order:

<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-compiler-plugin</artifactId>
    <version>${maven.compiler.plugin.version}</version>
	<configuration>
		<source>15</source>
		<target>15</target>
		<compilerArgs>--enable-preview</compilerArgs>
		<annotationProcessorPaths>
			<path>
				<groupId>org.projectlombok</groupId>
				<artifactId>lombok</artifactId>
				<version>${lombok.version}</version>
			</path>
			<path>
				<groupId>org.mapstruct</groupId>
				<artifactId>mapstruct-processor</artifactId>
				<version>${mapstruct.version}</version>
			</path>
		</annotationProcessorPaths>
	</configuration>
</plugin>

And of course you need to add dependencies:

<dependencies>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct</artifactId>
        <version>${mapstruct.version}</version>
    </dependency>
</dependencies>

After multiple attempts in my Spring Boot Maven project, the following finally worked:

Configuration of pom.xml:

1. The properties section:

    <properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<maven.compiler.target>11</maven.compiler.target>
    		<maven.compiler.source>11</maven.compiler.source>
    		<version.lombok>1.18.18</version.lombok>
    		<version.mapstruct>1.4.2.Final</version.mapstruct>
    		<version.mapstruct-lombok>0.2.0</version.mapstruct-lombok>
    	</properties>

2. The dependencies section:

    <dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<version>${version.lombok}</version>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.mapstruct</groupId>
			<artifactId>mapstruct</artifactId>
			<version>${version.mapstruct}</version>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok-mapstruct-binding</artifactId>
			<version>${version.mapstruct-lombok}</version>
		</dependency>

3. The build plugins section:

    <build>
    		<plugins>
    			<plugin>
    				<groupId>org.apache.maven.plugins</groupId>
    				<artifactId>maven-compiler-plugin</artifactId>
    				<version>3.5.1</version>
    				<configuration>
    					<source>9</source>
    					<target>9</target>
    					<annotationProcessorPaths>
    						<path>
    							<groupId>org.mapstruct</groupId>
    							<artifactId>mapstruct-processor</artifactId>
    							<version>${version.mapstruct}</version>
    						</path>
    						<path>
    							<groupId>org.projectlombok</groupId>
    							<artifactId>lombok</artifactId>
    							<version>${version.lombok}</version>
    						</path>
    						<path>
    							<groupId>org.projectlombok</groupId>
    							<artifactId>lombok-mapstruct-binding</artifactId>
    							<version>${version.mapstruct-lombok}</version>
    						</path>
    					</annotationProcessorPaths>
    				</configuration>
    			</plugin>
    		</plugins>
    	</build>

Hope this helps, my mapper before did not map the field values, but now these are mapper between the source and the target + the nested list of elements in each is also being mapped along with field values.

I had similar issues. Turned out my MapStruct version was outdated!

I used MapStruct version 1.1.0.Final, but for Lombok support at least 1.2.0.Final is required.

If anyone is reading this when using the latest Lombok and Mapstruct library versions:-

If you are using Lombok 1.18.16 or newer then you also need to add lombok-mapstruct-binding in order to make Lombok and MapStruct work together.

https://mapstruct.org/faq/#Can-I-use-MapStruct-together-with-Project-Lombok

For issues after upgrading Intellij to 2020.3 version, following solution worked for me. Use lombok version: 1.18.16, lombok-mapstruct-binding: 0.2.0

<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<version>1.18.16</version>
			<scope>provided</scope>
</dependency>
<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok-mapstruct-binding</artifactId>
			<version>0.2.0</version>
</dependency>

Change the order of the lombok and mapstruct plugin path in annotation processing section of plugins:

<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>3.5.1</version>
				<configuration>
					<source>11</source>
					<target>11</target>
					<annotationProcessorPaths>
						<path>
							<groupId>org.projectlombok</groupId>
							<artifactId>lombok</artifactId>
							<version>${org.projectlombok.version}</version>
						</path>
						<path>
							<groupId>org.mapstruct</groupId>
							<artifactId>mapstruct-processor</artifactId>
							<version>${org.mapstruct.version}</version>
						</path>

					</annotationProcessorPaths>
				</configuration>
			</plugin>
		</plugins>

If someone is still looking for this answer, I faced a similar issue with JOOQ + MapStruct Integration. The answer is the order of paths matters

• IntellijIdea 2020.2.3
• Java 8
• Spring Framework 2.4.0

My build snippet

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>${maven.compiler.plugin.version}</version>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
                <annotationProcessorPaths>
                    <path>
                        <groupId>org.projectlombok</groupId>
                        <artifactId>lombok</artifactId>
                        <version>${org.lombok.version}</version>
                    </path>
                    <path>
                        <groupId>org.mapstruct</groupId>
                        <artifactId>mapstruct-processor</artifactId>
                        <version>${mapstruct.version}</version>
                    </path>
                    <!-- This is needed when using Lombok 1.8.16 and above -->
                    <path>
                        <groupId>org.projectlombok</groupId>
                        <artifactId>lombok-mapstruct-binding</artifactId>
                        <version>${org.lombok-mapstruct-binding.version}</version>
                    </path>
                </annotationProcessorPaths>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>${spring.boot.version}</version>
        </plugin>
    </plugins>
</build>

The mapstruct was just returning a null instance. Recently I upgraded the Intellij version to 2020.3, and spring boot 2.4.0, and landed into this situation.

When I changed the spring version to 2.3.o.RELEASE, I could see after compilation is that mapstruct was building the mappings properly.

Going through the post that mapstruct has recently updated.. but it will take time.. :) so, for now, I moved from maven to Gradle project and all working absolutely fine.. sounds weird but true...

I would be thankful if anyone would post what exactly the right issue and what's the solution.

Apparently this is how you are supposed to load multiple annotation processors in Gradle

dependencies {
    implementation "org.mapstruct:mapstruct:1.4.2.Final", "org.projectlombok:lombok:1.18.20"
    annotationProcessor "org.mapstruct:mapstruct-processor:1.4.2.Final", "org.projectlombok:lombok:1.18.20", "org.projectlombok:lombok-mapstruct-binding:0.2.0"
}

I agree that the order does play its role, also when using gradle. In my case it was failing as soon I was adding subprojects { ... dependencyManagement{}} to the parent build.gradle in a multimodule setup.

I feel a right way to declare versions in pom.xml is to refer to something like this for versions instead of manually specifying versions of everything. e.g. maven-compiler-plugin.version, lombok.version is already present there

properties block -

<properties>
  <java.version>11</java.version>
  <mapstruct.version>1.4.2.Final</mapstruct.version>
  <lombok-mapstruct-binding.version>0.2.0</lombok-mapstruct-binding.version>
</properties>

dependencies block -

<dependencies>
  <!-- ... -->
  <dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<optional>true</optional>
  </dependency>

  <dependency>
      <groupId>org.mapstruct</groupId>
      <artifactId>mapstruct</artifactId>
      <version>${mapstruct.version}</version>
  </dependency>

  <dependency>
    <groupId>org.mapstruct</groupId>
    <artifactId>mapstruct-processor</artifactId>
    <version>${mapstruct.version}</version>
  </dependency>

  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok-mapstruct-binding</artifactId>
    <version>${lombok-mapstruct-binding.version}</version>
  </dependency>

  <!-- ... -->
</dependencies>

build block -

<build>
  <plugins>
    <plugin>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
      <configuration>
        <excludes>
          <exclude>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
          </exclude>
        </excludes>
      </configuration>
    </plugin>

    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-compiler-plugin</artifactId>
      <version>${maven-compiler-plugin.version}</version>
      <configuration>
        <source>${java.version}</source>
        <target>${java.version}</target>
        <annotationProcessorPaths>
          <path>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
          </path>

          <path>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok-mapstruct-binding</artifactId>
            <version>${lombok-mapstruct-binding.version}</version>
          </path>

          <path>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-processor</artifactId>
            <version>${mapstruct.version}</version>
          </path>
        </annotationProcessorPaths>
      </configuration>
    </plugin>
  </plugins>
</build>

For Spring-Boot the simplest configuration with exclude processing code from result jar:

pom.xml

     <dependencies>
         <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct</artifactId>
            <version>${mapstruct.version}</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok-mapstruct-binding</artifactId>
            <version>0.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.mapstruct</groupId>
            <artifactId>mapstruct-processor</artifactId>
            <version>${mapstruct.version}</version>
        </dependency>
        ....
    </dependencies>
    <build>
        <plugins>
            <!-- exclude from jar-->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok-mapstruct-binding</artifactId>
                        </exclude>
                        <exclude>
                            <groupId>org.mapstruct</groupId>
                            <artifactId>mapstruct</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
            ...
        </plugins>
    </build>

Without lombok-mapstruct-binding it also works fine.
Maybe somebody comments, what for does it needed?

In addition, also, correct versions have to be used.

See here