java: Unable to implement Repository method: PersonRepository.save(Object entity). No possible implementations found

Question

I'm making a small endpoint and it doesn't work for me. It is very simple, and for this I am using micronaut

My 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.autentia</groupId>
    <artifactId>autentia</artifactId>
    <version>0.1</version>
    <packaging>${packaging}</packaging>

    <parent>
        <groupId>io.micronaut</groupId>
        <artifactId>micronaut-parent</artifactId>
        <version>3.3.4</version>
    </parent>

    <properties>
        <packaging>jar</packaging>
        <jdk.version>11</jdk.version>
        <release.version>11</release.version>
        <micronaut.version>3.3.4</micronaut.version>
        <exec.mainClass>com.autentia.Application</exec.mainClass>
        <micronaut.runtime>netty</micronaut.runtime>
    </properties>

    <repositories>
        <repository>
            <id>central</id>
            <url>https://repo.maven.apache.org/maven2</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-inject</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-validation</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut.test</groupId>
            <artifactId>micronaut-test-junit5</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-http-client</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-http-server-netty</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-jackson-databind</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut</groupId>
            <artifactId>micronaut-runtime</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>io.micronaut.data</groupId>
            <artifactId>micronaut-data-hibernate-jpa</artifactId>
            <version>3.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>jakarta.annotation</groupId>
            <artifactId>jakarta.annotation-api</artifactId>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>io.micronaut.build</groupId>
                <artifactId>micronaut-maven-plugin</artifactId>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <!-- Uncomment to enable incremental compilation -->
                    <!-- <useIncrementalCompilation>false</useIncrementalCompilation> -->

                    <annotationProcessorPaths combine.children="append">
                        <path>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                            <version>1.18.22</version>
                        </path>
                        <path>
                            <groupId>io.micronaut</groupId>
                            <artifactId>micronaut-http-validation</artifactId>
                            <version>${micronaut.version}</version>
                        </path>
                        <path>
                            <groupId>io.micronaut.data</groupId>
                            <artifactId>micronaut-data-processor</artifactId>
                            <version>3.2.2</version>
                        </path>
                    </annotationProcessorPaths>
                    <compilerArgs>
                        <arg>-Amicronaut.processing.group=com.autentia</arg>
                        <arg>-Amicronaut.processing.module=autentia</arg>
                    </compilerArgs>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project> 

My repository:

import com.prueba.entity.Person;
import io.micronaut.data.annotation.Repository;
import io.micronaut.data.repository.CrudRepository;

@Repository
public interface PersonRepository extends CrudRepository<Person, Long> {

}

My entity:

import lombok.Getter;
import lombok.Setter;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
@Getter
@Setter
public class Person {

    @Id
    @GeneratedValue
    private Long Id;

    private String name;

    private String surname;

}

Finally, the error

java: Unable to implement Repository method: PersonRepository.findById(Object id). Cannot query entity [Person] on non-existent property: Id

What can I be doing wrong? Thank you

Answer 1

Ideally you should download or create micronaut project with Lombok dependency selected, so that you won't run into this issue.

But here is the guide if you want to add lombok later on in the project.

All you need to do is, add dependencies in correct order. The order of annotations processors seems to play important role here. Use these dependencies as mentioned below.

Note: This answer is based on gradle, but the concept should also work with Maven

Step-1: Use this below lombok annotation processor as the first thing in dependencies:

annotationProcessor("org.projectlombok:lombok")

Step-2: Then after annotation processors, use lombok compile time dependency:

compileOnly("org.projectlombok:lombok")

Step-3: Then you can write your rest of the dependencies:

implementation("io.micronaut.data:micronaut-data-hibernate-jpa")
runtimeOnly("ch.qos.logback:logback-classic")
...
...

build.gradle (dependencies section)

dependencies {

    /* Step 1 */
    annotationProcessor("org.projectlombok:lombok")
    annotationProcessor("io.micronaut:micronaut-http-validation")
    annotationProcessor("io.micronaut.data:micronaut-data-processor")
    annotationProcessor("io.micronaut.openapi:micronaut-openapi")

    /* Step 2 */
    compileOnly("org.projectlombok:lombok")

    /* Step 3 */
    implementation("io.micronaut:micronaut-http-client")
    implementation("io.micronaut:micronaut-jackson-databind")
    implementation("io.micronaut.flyway:micronaut-flyway")
    implementation("io.micronaut.oraclecloud:micronaut-oraclecloud-atp")
    implementation("io.micronaut.oraclecloud:micronaut-oraclecloud-sdk")
    implementation("io.micronaut.sql:micronaut-jdbc-hikari")
    implementation("jakarta.annotation:jakarta.annotation-api")
    implementation("io.micronaut.data:micronaut-data-hibernate-jpa")
    implementation("org.apache.commons:commons-lang3:3.12.0")
    implementation("io.swagger.core.v3:swagger-annotations")
    runtimeOnly("ch.qos.logback:logback-classic")
}