Migrate to Quarkus 2 from Quarkus 1

In this guide we'll look at using OpenRewrite to perform an automated migration from Quarkus 1.x to Quarkus 2.x.

Example Configuration

See various ways you can configure your project to run this recipe on the recipe reference page. This is also where you can find the full list of changes it will make.

Once you've configured your project, 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.

Before and After

Migrate Deprecated Mutiny APIs

package org.acme.demo.service;

import io.smallrye.mutiny.Multi;
import io.smallrye.mutiny.Uni;
import io.smallrye.mutiny.groups.MultiCollect;

import javax.enterprise.context.ApplicationScoped;
import java.time.Duration;
import java.util.List;
import java.util.concurrent.Executor;

@ApplicationScoped
public class FactorService {

    public static Uni<String> uniGreeting(String name) {
        return Uni.createFrom().item(name)
                .onItem()
                .apply(n -> String.format("Factor this %s", n));
    }

    public static Multi<String> greetings(int count, String name) {
        return Multi.createFrom().ticks().every(Duration.ofMillis(1))
                .onItem()
                .transform(n -> String.format("hello %s - %d", name, n))
                .transform()
                .byTakingFirstItems(count);
    }

    public static Uni<List<String>> collectItems(int count, String name) {
        Multi<String> multi = greetings(count, name);
        Uni<List<String>> uni = multi
                .collectItems()
                .asList();
        Executor e = command -> {
            System.out.print("something");
        };
        multi.subscribeOn(e);
        uni.subscribeOn(e);
        return uni;
    }

    public static MultiCollect<Long> hotStreamGreetings(int count, String name) {
        return Multi.createFrom().ticks().every(Duration.ofMillis(1))
                .transform()
                .toHotStream()
                .collectItems();
    }
}

package org.acme.demo.service;

import io.smallrye.mutiny.Multi;
import io.smallrye.mutiny.Uni;
import io.smallrye.mutiny.groups.MultiCollect;

import javax.enterprise.context.ApplicationScoped;
import java.time.Duration;
import java.util.List;
import java.util.concurrent.Executor;

@ApplicationScoped
public class FactorService {

    public static Uni<String> uniGreeting(String name) {
        return Uni.createFrom().item(name)
                .onItem()
                .transform(n -> String.format("Factor this %s", n));
    }

    public static Multi<String> greetings(int count, String name) {
        return Multi.createFrom().ticks().every(Duration.ofMillis(1))
                .onItem()
                .transform(n -> String.format("hello %s - %d", name, n))
                .select()
                .first(count);
    }

    public static Uni<List<String>> collectItems(int count, String name) {
        Multi<String> multi = greetings(count, name);
        Uni<List<String>> uni = multi
                .collect()
                .asList();
        Executor e = command -> {
            System.out.print("something");
        };
        multi.runSubscriptionOn(e);
        uni.runSubscriptionOn(e);
        return uni;
    }

    public static MultiCollect<Long> hotStreamGreetings(int count, String name) {
        return Multi.createFrom().ticks().every(Duration.ofMillis(1))
                .toHotStream()
                .collect();
    }
}

Migrate `io.quarkus.qute.api.*`

package org.acme.demo.misc;

import io.quarkus.qute.Template;
import io.quarkus.qute.TemplateInstance;
import io.quarkus.qute.api.CheckedTemplate;
import io.quarkus.qute.api.ResourcePath;
import io.quarkus.scheduler.Scheduled;

public class ReportGenerator {
    @ResourcePath("reports/v1/report_01")
    Template report;

    @Scheduled(cron = "0 30 * * * ?")
    void generate() {
        String result = report
                .data("samples", new Object())
                .render();
    }
}

@CheckedTemplate
class HelloTemplate {
    public static native TemplateInstance hello(String name);
}

package org.acme.demo.misc;

import io.quarkus.qute.CheckedTemplate;
import io.quarkus.qute.Location;
import io.quarkus.qute.Template;
import io.quarkus.qute.TemplateInstance;
import io.quarkus.scheduler.Scheduled;

public class ReportGenerator {
    @Location("reports/v1/report_01")
    Template report;

    @Scheduled(cron = "0 30 * * * ?")
    void generate() {
        String result = report
                .data("samples", new Object())
                .render();
    }
}

@CheckedTemplate
class HelloTemplate {
    public static native TemplateInstance hello(String name);
}

Migrate `application.properties` keys and values

quarkus.dev.instrumentation=true
smallrye.jwt.sign.key-location=/keys/signing.pem
smallrye.jwt.encrypt.key-location=/keys/encrypt.pem
quarkus.quartz.force-start=true
quarkus.quartz.store-type=db
quarkus.neo4j.pool.metrics-enabled=true
# ...
# and other property keys/values as according to the Quarkus migration guide

quarkus.live-reload.instrumentation=true
smallrye.jwt.sign.key.location=/keys/signing.pem
smallrye.jwt.encrypt.key.location=/keys/encrypt.pem
quarkus.quartz.start-mode=forced
quarkus.quartz.store-type=jdbc-cmt
quarkus.neo4j.pool.metrics.enabled=true
# ...
# and other property keys/values as according to the Quarkus migration guide

Known Limitations

Unsupported Functionality Issue

Unsupported Functionality	Issue
`@ConfigProperties`-annotated interfaces migrate to using `@ConfigMapping`, but not yet `@ConfigProperties`-annotated classes	#24
Kubernetes Client 5.4	-
Vert.x 4.0	-

@ConfigProperties-annotated interfaces migrate to using @ConfigMapping, but not yet @ConfigProperties-annotated classes

#24

Kubernetes Client 5.4

Vert.x 4.0