Updated to latest versions and adapted tests to those versions

.github/workflows/linux_maven.yml

@@ -16,10 +16,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'adopt'
         cache: maven
     - name: Build with Maven

.github/workflows/release_maven.yml

@@ -13,10 +13,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'adopt'
         cache: maven
     - name: Build and Deploy with Maven

.github/workflows/windows_maven.yml

@@ -17,10 +17,10 @@ jobs:
     runs-on: windows-latest
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'adopt'
         cache: maven
     - name: Build with Maven

README.md

@@ -84,7 +84,7 @@ the same way as e.g. your co-workers do with their Eclipse IDE.
 
 Compatibility
 -------------
-Compatible with NetBeans 12.0+ and JDK 17+.
+Compatible with NetBeans 12.0+ and JDK 21+.
 
 Downloads
 ---------