Update auf Java 21

Author: ChristianHoesel

.devcontainer/devcontainer.json

@@ -3,7 +3,7 @@
 {
 	"name": "Java",
 	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-	"image": "mcr.microsoft.com/devcontainers/java:3-17-bookworm",
+	"image": "mcr.microsoft.com/devcontainers/java:3-21-bookworm",
 
 	"features": {
 		"ghcr.io/devcontainers/features/java:1": {

.github/workflows/maven-ci.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '17', '21', '25' ]
+        java: [ '21', '25' ]
 
     steps:
     - uses: actions/checkout@v7

README.md

@@ -5,6 +5,9 @@
 # com.bitctrl
 Allgemeine Bibliothek für BitCtrl-Projekte
 
+## Version 3.1.0
+ - Update auf Java 21
+
 ## Version 3.0.1
  - Update der Dependencies
 

pom.xml

@@ -6,16 +6,16 @@
 
 	<groupId>com.bitctrl</groupId>
 	<artifactId>com.bitctrl</artifactId>
-	<version>3.0.2-SNAPSHOT</version>
+	<version>3.1.0-SNAPSHOT</version>
 
 	<name>Allgemeine BitCtrl-Bibliothek</name>
 	<url>http://bitctrl.github.io/${project.artifactId}/</url>
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-		<maven.compiler.source>17</maven.compiler.source>
-		<maven.compiler.target>17</maven.compiler.target>
+		<maven.compiler.source>21</maven.compiler.source>
+		<maven.compiler.target>21</maven.compiler.target>
 	</properties>
 
 	<licenses>
@@ -46,11 +46,6 @@
 		<url>https://github.com/bitctrl/${project.artifactId}/</url>
 	</issueManagement>
 
-	<ciManagement>
-		<system>Travis-CI</system>
-		<url>https://travis-ci.org/bitctrl/${project.artifactId}/</url>
-	</ciManagement>
-
 	<profiles>
 		<profile>
 			<id>bitctrl</id>