Fix java version

.github/workflows/maven.yml

@@ -11,10 +11,10 @@ jobs:
     - name: Checkout Repository
       uses: actions/checkout@v2
     
-    - name: Set up JDK 11
+    - name: Set up JDK 16
       uses: actions/setup-java@v2
       with:
-        java-version: 11
+        java-version: 16
         distribution: 'adopt'
 
     - name: Cache Maven packages

pom.xml

@@ -15,8 +15,8 @@
     </modules>
 
     <properties>
-        <maven.compiler.source>16</maven.compiler.source>
+        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>16</maven.compiler.target>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <build>
@@ -26,8 +26,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>16</source>
+                    <source>11</source>
-                    <target>16</target>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <plugin>

spigot/pom.xml

@@ -12,8 +12,8 @@
     <artifactId>spigot</artifactId>
 
     <properties>
-        <maven.compiler.source>16</maven.compiler.source>
+        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>16</maven.compiler.target>
+        <maven.compiler.target>11</maven.compiler.target>
     </properties>
 
     <repositories>