Build as multi release jar

- make jakarta and javax annotation modules optional at runtime
- update GitHub Action to JDK 11
- added module info in java9 source folder
- added executions for java 8 and 9
- removed automatic module - added multi release entry to manifest

Author: Til7701

.github/workflows/maven_release.yml

@@ -15,10 +15,10 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - name: Set up JDK 8
+      - name: Set up JDK 11
         uses: actions/setup-java@v3
         with:
-          java-version: 8
+          java-version: 11
           distribution: 'temurin'
       - name: Cache Maven packages
         uses: actions/cache@v3
@@ -37,10 +37,10 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
-      - name: Set up JDK 8
+      - name: Set up JDK 11
         uses: actions/setup-java@v3
         with:
-          java-version: 8
+          java-version: 11
           distribution: 'temurin'
       - name: Cache Maven packages
         uses: actions/cache@v3
@@ -74,7 +74,7 @@ jobs:
       - name: Set up Maven Central Repository
         uses: actions/setup-java@v3
         with:
-          java-version: 8
+          java-version: 11
           distribution: 'temurin'
           server-id: central
           server-username: MAVEN_USERNAME

pom.xml

@@ -81,10 +81,32 @@
             <plugin>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.14.0</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                </configuration>
+                <executions>
+                    <execution>
+                        <id>compile-java-8</id>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                        <configuration>
+                            <source>1.8</source>
+                            <target>1.8</target>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>compile-java-9</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                        <configuration>
+                            <release>9</release>
+                            <compileSourceRoots>
+                                <compileSourceRoot>${project.basedir}/src/main/java9</compileSourceRoot>
+                            </compileSourceRoots>
+                            <multiReleaseOutput>true</multiReleaseOutput>
+                        </configuration>
+                    </execution>
+                </executions>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -93,7 +115,7 @@
                 <configuration>
                     <archive>
                         <manifestEntries>
-                            <Automatic-Module-Name>org.openapitools.jackson.nullable</Automatic-Module-Name>
+                            <Multi-Release>true</Multi-Release>
                         </manifestEntries>
                     </archive>
                 </configuration>

src/main/java9/module-info.java

@@ -0,0 +1,7 @@
+module org.openapitools.jackson.nullable {
+    requires com.fasterxml.jackson.databind;
+    requires static jakarta.validation;
+    requires static java.validation;
+
+    exports org.openapitools.jackson.nullable;
+}