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Migrate to Spring Boot 3 from Spring Boot 2

In this tutorial, we'll use OpenRewrite to perform an automated migration from Spring Boot 2.x to Spring Boot 3.5.

Configuration​

This recipe has no required configuration options. It can be activated by adding a dependency on `org.openrewrite.recipe:rewrite-spring` in your build file or by running a shell command (in which case no build changes are needed):

  1. Add the following to your build.gradle file:
    build.gradle
    plugins {
        id("org.openrewrite.rewrite") version("latest.release")
    }

    rewrite {
        activeRecipe("org.openrewrite.java.spring.boot3.UpgradeSpringBoot_3_5")
    }

    repositories {
        mavenCentral()
    }

    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-spring:6.28.2")
    }
  2. Run gradle rewriteRun to run the recipe.

For the full list of changes this recipe will make, see the recipe reference page.

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​

Example Java Class​

Before​

package org.openrewrite.example;

import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
import org.springframework.beans.factory.annotation.Autowired;

public class OwnerController {
    ...

    @Autowired
    public OwnerController(OwnerRepository clinicService) {
        this.owners = clinicService;
    }

    @RequestMapping(value = "/owners/what")
    public String getWhat() {
        return "multiple method types omg";
    }

    @ModelAttribute("owner")
    public Owner findOwner(@PathVariable("ownerId") int ownerId) {
        return this.owners.findById(ownerId);
    }

    @RequestMapping(value = "/owners/{ownerId}/edit", method = POST)
    public String processUpdateOwnerForm(@Valid Owner owner, BindingResult result, @PathVariable("ownerId") int ownerId) {
        if (result.hasErrors()) {
            return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
        } else {
            owner.setId(ownerId);
            this.owners.save(owner);
            return "redirect:/owners/{ownerId}";
        }
    }

}

After​

package org.openrewrite.example;

import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import jakarta.persistence.MappedSuperclass

public class OwnerController {
    ...

    public OwnerController(OwnerRepository clinicService) {
        this.owners = clinicService;
    }

    @GetMapping("/owners/what")
    public String getWhat() {
        return "multiple method types omg";
    }

    @ModelAttribute("owner")
    public Owner findOwner(@PathVariable int ownerId) {
        return this.owners.findById(ownerId);
    }

    @PostMapping("/owners/{ownerId}/edit")
    public String processUpdateOwnerForm(@Valid Owner owner, BindingResult result, @PathVariable int ownerId) {
        if (result.hasErrors()) {
            return VIEWS_OWNER_CREATE_OR_UPDATE_FORM;
        } else {
            owner.setId(ownerId);
            this.owners.save(owner);
            return "redirect:/owners/{ownerId}";
        }
    }
}

Example Java Test​

Before​

package org.openrewrite.example;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.junit4.SpringRunner;

...

@RunWith(SpringRunner.class)
@WebMvcTest(OwnerController.class)
public class OwnerControllerTests {

    @Before
    public void setup() {
        ...
    }

    @Test
    public void testInitCreationForm() throws Exception {
        ...  
    }
}

After​

package org.openrewrite.example;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

...

@WebMvcTest(OwnerController.class)
class OwnerControllerTests {

    @BeforeEach
    void setup() {
        ...
    }

    @Test
    void testInitCreationForm() throws Exception {
        ...  
    }
}

Example application.properties file​

Before​

spring.datasource.schema=classpath*:db/${database}/schema.sql
spring.datasource.data=classpath*:db/${database}/data.sql

management.contextPath=/manage

After​

spring.sql.init.schema-locations=classpath*:db/${database}/schema.sql
spring.sql.init.data-locations=classpath*:db/${database}/data.sql

management.server.base-path=/manage

Example maven pom.xml file​

Before​

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.18.RELEASE</version>
</parent>

<properties>
    <java.version>11</java.version>
    <wro4j.version>1.10.1</wro4j.version>
    <thymeleaf.version>3.0.15.RELEASE</thymeleaf.version>
</properties>

<dependencies>
    <dependency>
        <groupId>jakarta.inject</groupId>
        <artifactId>jakarta.inject-api</artifactId>
        <version>1.0.3</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
</dependencies>

After​

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.5.0</version>
</parent>

<properties>
    <java.version>17</java.version>
    <wro4j.version>1.10.1</wro4j.version>
</properties>

<dependencies>
    <dependency>
       <groupId>jakarta.inject</groupId>
       <artifactId>jakarta.inject-api</artifactId>
       <version>2.1.1.MR</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
        <version>3.5.0</version>
    </dependency>
</dependencies>

See how this recipe works across multiple open-source repositories​

Run this recipe on OSS repos at scale with the Moderne SaaS.

The community edition of the Moderne platform enables you to easily run recipes across thousands of open-source repositories.

Please contact Moderne for more information about safely running the recipes on your own codebase in a private SaaS.

Using Moderne to upgrade Spring versions​