Lombok and module-info.java

Question

I am converting an existing Java library to use module-info.java. I use Lombok and generics extensively. When I run "mvn package" I get a ton of errors that follow this pattern:

[ERROR] /projects/app/src/main/java/com/whatever/app/server/handlers/HandlerCreateForumPost.java:[116,13] cannot find symbol
[ERROR]   symbol:   method <com.whatever.app.common.messages.CreateForumPostResults>builder()
[ERROR]   location: class com.whatever.app.common.Response

The statement that causes the error is:

return Response
    .<CreateForumPostResults>builder()
    .success(true)
    .requestID(context.getRequestID())
    .results(
        CreateForumPostResults
            .builder()
            .id(forumPostID)
            .build()
    )
    .build();

Line 116 reported in the error is the one that reads ".builder()".

The Response class lives in com.whatever.app.common and is defined as:

package com.whatever.app.common;

import lombok.Getter;
import lombok.Setter;
import lombok.experimental.SuperBuilder;
import lombok.extern.jackson.Jacksonized;

@SuperBuilder
@Jacksonized
@Getter
@Setter
public class Response<T extends Response.Results> {
    boolean success;
    String message;
    String requestID;
    T results;

    @SuperBuilder
    @Jacksonized
    @Getter
    @Setter
    public static class Results {

    }
}

The CreateForumPostResults class lives in com.whatever.app.common.messages and extends Response.Results:

package com.whatever.app.common.messages;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.whatever.app.common.AppResponse;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.SuperBuilder;
import lombok.extern.jackson.Jacksonized;

import java.util.UUID;

@SuperBuilder
@Getter
@Setter
@Jacksonized
public class AppCreateForumPostResults extends AppResponse.Results {
    @JsonProperty("id")
    UUID id;
}

My module-info.java looks like this:

module com.whatever.app.common {
    exports com.whatever.app.common;
    exports com.whatever.app.common.messages;

    requires com.fasterxml.jackson.annotation;
    requires com.fasterxml.jackson.core;
    requires com.fasterxml.jackson.databind;
    requires com.fasterxml.jackson.datatype.jsr310;
    requires com.google.common;
    requires lombok;
}

My POM is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         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>

    <parent>
        <artifactId>app</artifactId>
        <groupId>com.whatever</groupId>
        <version>0.9</version>
    </parent>

    <artifactId>app-common</artifactId>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <maven.compiler.plugin.version>3.8.1</maven.compiler.plugin.version>

        <maven.jar.plugin.version>3.2.0</maven.jar.plugin.version>

        <guava-version>23.0</guava-version>

        <jackson-version>2.13.1</jackson-version>

        <lombok-version>1.18.22</lombok-version>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>${maven.compiler.plugin.version}</version>
                <configuration>
                    <source>${maven.compiler.source}</source>
                    <target>${maven.compiler.target}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>${maven.jar.plugin.version}</version>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson-version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</artifactId>
            <version>${jackson-version}</version>
        </dependency>

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>${guava-version}</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok-version}</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>
</project>

I suspect that there's some magic incantation needed to make Lombok's @Builder annotation (and possibly others) work with module-info.java, or perhaps something related to generics that is causing this to break, but I haven't been able to figure out what it is.

What am I doing wrong?

Any insights are greatly appreciated.

Answer 1

As is often the case, taking the time to write this question out clearly lead me to find the answer I was looking for. Short version, I needed to modify the maven-compiler-plugin configuration as follows:

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