Kod źródłowy do wpisu o Dockerze i Spring Boocie znajdującym się pod adresem:

Dockerfile

FROM adoptopenjdk/openjdk14:alpine-jre

WORKDIR /opt

COPY target/spring-docker.jar application.jar

ENTRYPOINT ["java", "-jar", "application.jar"]

Main.java

@SpringBootApplication
@Controller
public class Main {

    @RequestMapping("/")
    @ResponseBody
    public String index() {
        return "<h1>Hello World!</h1>";
    }

    public static void main(String[] args) {
        SpringApplication.run(Main.class);
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>pl.mloza</groupId>
    <artifactId>spring-boot-docker</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-parent</artifactId>
                <version>2.2.4.RELEASE</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

    <build>
        <finalName>spring-docker</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <mainClass>pl.mloza.Main</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <release>14</release>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>