Require Java 11 compiler (JRE 1.8 compatible)

Author: sgdc3

README.md

@@ -116,16 +116,16 @@ You can also create your own translation file and, if you want, you can share it
 ## Requirements
 
 ##### Compiling requirements:
->- JDK 8 (JDK 17 is recommended)
+>- JDK 11 (JDK 17 is recommended)
 >- Maven
 >- Git/Github (Optional)
 
 ##### How to compile the project:
->- Clone the project with Git/Github
+>- Clone the project with Git/GitHub
 >- Execute command "mvn clean package"
 
 ##### Running requirements:
->- Java 8 (Java 11 is recommended)
+>- Java 8 (Java 17 is recommended)
 >- Paper or Spigot (1.8.X and up)<br>
    (In case you use Thermos, Cauldron or similar, you have to update the SpecialSource library to support Java 8 plugins.
    HowTo: https://github.com/games647/FastLogin/issues/111#issuecomment-272331347)

pom.xml

@@ -60,8 +60,11 @@
         <!-- Environment properties -->
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <java.version>1.8</java.version>
-        <maven.minimumVersion>3.6.0</maven.minimumVersion>
+        <java.source>1.8</java.source>
+        <java.target>1.8</java.target>
+        <java.apiVersion>8</java.apiVersion>
+        <java.compiler.minimumVersion>11</java.compiler.minimumVersion>
+        <maven.minimumVersion>3.6.3</maven.minimumVersion>
 
         <!-- Dependencies versions -->
         <spigot.version>1.19-R0.1-SNAPSHOT</spigot.version>
@@ -173,6 +176,9 @@
                                 <requireMavenVersion>
                                     <version>${maven.minimumVersion}</version>
                                 </requireMavenVersion>
+                                <requireJavaVersion>
+                                    <version>[11,)</version>
+                                </requireJavaVersion>
                             </rules>
                             <fail>true</fail>
                         </configuration>
@@ -197,8 +203,9 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.10.1</version>
                 <configuration>
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <source>${java.source}</source>
+                    <target>${java.target}</target>
+                    <release>${java.apiVersion}</release>
                 </configuration>
             </plugin>
             <!-- Generate test coverage reports -->