added docker support

Dockerfile

@@ -0,0 +1,18 @@
+FROM alpine as mvn
+
+RUN apk add maven
+
+
+FROM mvn as builder
+
+WORKDIR /build
+ADD . .
+RUN mvn package
+
+
+FROM eclipse-temurin:17-jdk-alpine
+
+WORKDIR /backend
+COPY --from=builder /build/target/swa-jodel-backend.jar .
+
+ENTRYPOINT ["java","-jar","/backend/swa-jodel-backend.jar"]

pom.xml

@@ -14,7 +14,7 @@
     <name>SWA-Jodel</name>
     <description>SWA-Jodel</description>
     <properties>
-        <java.version>22</java.version>
+        <java.version>21</java.version>
     </properties>
     <dependencies>
         <dependency>
@@ -35,6 +35,7 @@
     </dependencies>
 
     <build>
+        <finalName>swa-jodel-backend</finalName>
         <plugins>
             <plugin>
                 <groupId>org.springframework.boot</groupId>