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Migrate to Micronaut 4 from Micronaut 3
In this guide, we'll look at using OpenRewrite to perform an automated migration from Micronaut 3.x to Micronaut 4.x
If you want to learn more about the process that went into developing these recipes, check out the Micronaut framework 4.0 release blog post.
Gradle
Maven
build.gradle
plugins {
id("org.openrewrite.rewrite") version("6.5.6")
}
rewrite {
activeRecipe("org.openrewrite.java.micronaut.Micronaut3to4Migration")
}
repositories {
mavenCentral()
}
dependencies {
rewrite(platform("org.openrewrite.recipe:rewrite-recipe-bom:2.5.0"))
rewrite("org.openrewrite.recipe:rewrite-micronaut")
}
pom.xml
<project>
<build>
<plugins>
<plugin>
<groupId>org.openrewrite.maven</groupId>
<artifactId>rewrite-maven-plugin</artifactId>
<version>5.13.0</version>
<configuration>
<activeRecipes>
<recipe>org.openrewrite.java.micronaut.Micronaut3to4Migration</recipe>
</activeRecipes>
</configuration>
<dependencies>
<dependency>
<groupId>org.openrewrite.recipe</groupId>
<artifactId>rewrite-micronaut</artifactId>
<version>2.1.1</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
</project>
At this point, you're ready to execute the migration by running
mvn rewrite:run or gradlew rewriteRun. After running the migration you can inspect the results with git diff (or equivalent), manually fix anything that wasn't able to be migrated automatically, and commit the results.These include:
javax.annotation.*javax.persistence.*javax.validation.*
Before
After
import javax.annotation.PostConstruct;
import javax.persistence.GenerationType;
import javax.validation.constraints.NotBlank;
import javax.validation.Valid;
import javax.validation.constraints.NotNull;
// ...
import jakarta.annotation.PostConstruct;
import jakarta.persistence.GenerationType;
import jakarta.validation.constraints.NotBlank;
import jakarta.validation.Valid;
import jakarta.validation.constraints.NotNull;
// ...
An
HttpRequest type parameter has been added to some interfaces.Before
After
import io.micronaut.http.HttpRequest;
import io.micronaut.security.authentication.AuthenticationProvider;
import io.micronaut.security.authentication.AuthenticationRequest;
import io.micronaut.security.authentication.AuthenticationResponse;
import org.reactivestreams.Publisher;
import java.io.Serializable;
public class AuthProvPass implements AuthenticationProvider, Serializable {
@Override
public Publisher<AuthenticationResponse> authenticate(HttpRequest<?> httpRequest,
AuthenticationRequest<?, ?> authenticationRequest) {
return null;
}
}
import io.micronaut.http.HttpRequest;
import io.micronaut.security.authentication.AuthenticationProvider;
import io.micronaut.security.authentication.AuthenticationRequest;
import io.micronaut.security.authentication.AuthenticationResponse;
import org.reactivestreams.Publisher;
import java.io.Serializable;
public class AuthProvPass implements AuthenticationProvider<HttpRequest<?>>, Serializable {
@Override
public Publisher<AuthenticationResponse> authenticate(HttpRequest<?> httpRequest,
AuthenticationRequest<?, ?> authenticationRequest) {
return null;
}
}
These include:
- Micronaut Retry
- Micronaut Session
- Micronaut Websocket
- SnakeYaml
build.gradle
pom.xml
Before
plugins {
id("io.micronaut.application") version "%s"
}
repositories {
mavenCentral()
}
dependencies {
implementation("io.micronaut:micronaut-session")
}
After
plugins {
id("io.micronaut.application") version "%s"
}
repositories {
mavenCentral()
}
dependencies {
implementation "io.micronaut:micronaut-retry"
implementation "io.micronaut:micronaut-websocket"
implementation("io.micronaut.session:micronaut-session")
runtimeOnly "org.yaml:snakeyaml"
}
Before
<project>
<groupId>com.mycompany.app</groupId>
<artifactId>my-app</artifactId>
<version>1</version>
<parent>
<groupId>io.micronaut.platform</groupId>
<artifactId>micronaut-parent</artifactId>
<version>%s</version>
</parent>
<dependencies>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-session</artifactId>
</dependency>
</dependencies>
</project>
After
<project>
<groupId>com.mycompany.app</groupId>
<artifactId>my-app</artifactId>
<version>1</version>
<parent>
<groupId>io.micronaut.platform</groupId>
<artifactId>micronaut-parent</artifactId>
<version>%s</version>
</parent>
<dependencies>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-retry</artifactId>
</dependency>
<dependency>
<groupId>io.micronaut</groupId>
<artifactId>micronaut-websocket</artifactId>
</dependency>
<dependency>
<groupId>io.micronaut.session</groupId>
<artifactId>micronaut-session</artifactId>
</dependency>
<dependency>
<groupId>org.yaml</groupId>
<artifactId>snakeyaml</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
</project>
Before
After
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<withJansi>true</withJansi>
<!-- encoders are assigned the type
ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
<encoder>
<pattern>%cyan(%d{HH:mm:ss.SSS}) %gray([%thread]) %highlight(%-5level) %magenta(%logger{36}) - %msg%n</pattern>
</encoder>
</appender>
<root level="info">
<appender-ref ref="STDOUT" />
</root>
</configuration>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<!-- encoders are assigned the type
ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
<encoder>
<pattern>%cyan(%d{HH:mm:ss.SSS}) %gray([%thread]) %highlight(%-5level) %magenta(%logger{36}) - %msg%n</pattern>
</encoder>
</appender>
<root level="info">
<appender-ref ref="STDOUT" />
</root>
</configuration>