Quarkus 是一个目前非常火的 Java 应用开发框架，定位是轻量级的微服务框架。，Quarkus 提供了优秀的容器化整合能力，相较于传统开发框架（Spring Boot）有着更快的启动速度、更小的内存消耗、更短的服务响应。

本文将演示将 SpringBoot 迁移至 Quarkus

Spring Boot 示例程序

使用 JPA 完成 数据库的增删改查操作，基础代码如下

• maven 依赖

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>

• jpa crud

public interface DemoUserDao extends CrudRepository<DemoUser, Long> {
}

迁移至 Quarkus

• quarkus-bom 管理了全部 quarkus 插件 maven 依赖的版本信息，引入后所有依赖不需要再定义版本。

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>io.quarkus</groupId>
				<artifactId>quarkus-bom</artifactId>
				<version>1.10.5.Final</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

• 迁移 spring-web 、spring-jpa 至 quarkus 技术栈。

<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-spring-data-jpa</artifactId>
</dependency>
<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-spring-web</artifactId>
</dependency>

• 配置文件调整 (还是在 application.yml)

quarkus.datasource.db-kind=mysql
quarkus.datasource.jdbc.driver=com.mysql.cj.jdbc.Driver
quarkus.datasource.username=root
quarkus.datasource.password=root
quarkus.datasource.jdbc.url=jdbc:mysql://localhost:3306/pig_demo?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedStatements=TRUE

• Main 方法调整为 实现 QuarkusApplication ，且需要通过 Quarkus.waitForExit() 保持服务运行。

@QuarkusMain
public class SimpleApplication implements QuarkusApplication {
	public static void main(String[] args) {
		Quarkus.run(SimpleApplication.class,args);
	}
	@Override
	public int run(String... args) {
		Quarkus.waitForExit();
		return 0;
	}
}

启动运行

main 方法启动, 输出 Quarkus banner

__  ____  __  _____   ___  __ ____  ______
 --/ __ \/ / / / _ | / _ \/ //_/ / / / __/
 -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \
--\___\_\____/_/ |_/_/|_/_/|_|\____/___/
2021-01-12 22:31:46,341 INFO  [io.qua.arc.pro.BeanProcessor] (build-21) Found unrecommended usage of private members (use package-private instead) in application beans:
	- @Inject field com.example.simple.controller.DemoController#userDao
2021-01-12 22:31:48,702 INFO  [io.quarkus] (Quarkus Main Thread) Quarkus 1.10.5.Final on JVM started in 4.613s. Listening on: http://localhost:8080
2021-01-12 22:31:48,703 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2021-01-12 22:31:48,703 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, mutiny, narayana-jta, resteasy, resteasy-jackson, smallrye-context-propagation, spring-data-jpa, spring-di, spring-web]

非常重要的是输出了当前已经安装的功能

Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, mutiny, narayana-jta, resteasy, resteasy-jackson, smallrye-context-propagation, spring-data-jpa, spring-di, spring-web]

【扩展】 actuator 监控迁移

• 添加以下依赖

<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-smallrye-health</artifactId>
</dependency>

• 指定访问监控断点路径

quarkus.smallrye-health.root-path=/actuator/health

• 访问监控检查断点测试

 curl http://localhost:8080/actuator/health
{
    "status": "UP",
    "checks": [
        {
            "name": "Database connections health check",
            "status": "UP"
        }
    ]
}⏎

【扩展】Flyway 迁移

• 添加 quarkus flyway 插件

<dependency>
  <groupId>io.quarkus</groupId>
  <artifactId>quarkus-flyway</artifactId>
</dependency>

• 指定插件启动策略即可

quarkus.flyway.migrate-at-start=true

>>> 源码 https://gitee.com/log4j/pig，欢迎署名转载 <<<