java - MapStruct and Lombok not working together

Question

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?

Answer 1

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.