CODEWITHSUNDEEP
kotlinlombokprintln
Chris Kessel
Chris Kessel

Reputation: 5875

Kotlin doesn't see Java Lombok accessors?

Using Kotlin 1.0.0 release (compiling in IntelliJ 15).

println(myPojoInstance.foo)

When it tries to compile code (in IntelliJ or Gradle) that references Lombok based POJOs it gives the error "Cannot access 'foo': it is 'private' in "MyPojo". Which is true, they're all private and my object has @Value @Builder for lombok annotations.

I've tried specifically calling getFoo(), but it says "unresolved reference for getFoo". There's perhaps some trick to make Kotlin aware of how to handle the lombok annotations?

Upvotes: 97

Views: 35130

Answers (5)

Pavel S.
Pavel S.

Reputation: 1336

As it was mentioned in comments above, delombok helps. In case of maven build, it would be:

<plugin>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok-maven-plugin</artifactId>
    <version>${lombok.version}.0</version>
    <executions>
        <execution>
            <id>delombok</id>
            <phase>generate-sources</phase>
            <goals>
                <goal>delombok</goal>
            </goals>
            <configuration>
                <formatPreferences>
                    <javaLangAsFQN>skip</javaLangAsFQN>
                </formatPreferences>
                <verbose>true</verbose>
            </configuration>
        </execution>
        <execution>
            <id>test-delombok</id>
            <phase>generate-test-sources</phase>
            <goals>
                <goal>testDelombok</goal>
            </goals>
            <configuration>
                <verbose>true</verbose>
            </configuration>
        </execution>
    </executions>
</plugin>

Upvotes: 6

Onema
Onema

Reputation: 7582

There is a Kotlin compiler plugin for lombok. It is still experimental and it can be used with Gradle or Maven.

It only supports a hand full of annotations, including

  • @Getter, @Setter
  • @NoArgsConstructor, @RequiredArgsConstructor, and @AllArgsConstructor
  • @Data
  • @With
  • @Value

Seem to work as expected. Unfortunately, they do not support the @Builder annotation but you can request to be added in YouTrack

See the Lombok compiler plugin in the kotlin documentation for more information.

Update 1

The @Builder annotation ticket mentioned above has been fixed! The target version for the fix is 1.8.0-Beta.

Upvotes: 23

abgalphabet YEUNG
abgalphabet YEUNG

Reputation: 411

Looks like it works if you use delombok according to site and add the target/generated-sources/delombok folder in the pom.xml under build > plugins > plugin > kotlin-maven-plugin

Upvotes: 4

Navid Rojiani
Navid Rojiani

Reputation: 81

To add to Sergey Mashkov's response (adding here I don't have enough rep points to comment on it), here's an example app of a Gradle multi-project setup where Kotlin can see the Lombok-generated code (without kapt or delomboking. Caveats do apply - namely, Kotlin can call the Java code, but Java can't call the Kotlin code in that particular module (as this would create a circular dependency). This kind of build might be suitable if you have an existing Java codebase and all new code is written in Kotlin, though.

I would love to see full Lombok/Kotlin support, however. While Kotlin is fully interoperable with Java, the reality is that Lombok is very widely used, and this issue may prevent a large number of developers who would like to switch to Kotlin from doing so.

Upvotes: 6

Sergey Mashkov
Sergey Mashkov

Reputation: 4760

Generally, no, it doesn't. The reason of that behavior is that Lombok is an annotation processor for javac but when the kotlin compiler runs it uses javac as well but with no annotation processing so this is why kotlin don't see declarations that wasn't yet generated.

The only workaround for now is to define strict compilation order: Java first and after that kotlin. Unfortunately this approach has great disadvantage: you can't use Kotlin code from Java in this case. To workaround it you may need multimodule project that may cause a lot of pain

Upvotes: 95

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