Merge pull request #1225 from apache/WW-5531-jre8-compat

WW-5531 Enforce JRE8 compatibility (when compiled on JDK9+)

Author: kusalk

pom.xml

@@ -183,6 +183,15 @@
                 </pluginManagement>
             </build>
         </profile>
+        <profile>
+            <id>jdk9plus</id>
+            <activation>
+                <jdk>[9,)</jdk>
+            </activation>
+            <properties>
+                <maven.compiler.release>8</maven.compiler.release>
+            </properties>
+        </profile>
         <profile>
             <id>jdk17</id>
             <activation>