micromata · nilsschmidthamburg · Aug 29, 2025
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
@@ -19,10 +19,10 @@ jobs:
         uses: actions/checkout@v3
       - 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: 'temurin'
 
       - name: Cache Gradle dependencies

diff --git a/Dockerfile b/Dockerfile
@@ -1,4 +1,4 @@
-FROM openjdk:17-slim
+FROM openjdk:21-slim
 
 # Argument for JAR file name to use in working directory:
 ARG JAR_FILE

diff --git a/README.adoc b/README.adoc
@@ -34,7 +34,7 @@ Or simply use the fastest way: https://projectforge.org/docs/installation/[Insta
 ====
 
 1. Checkout: `git clone [email protected]:micromata/projectforge.git`
-2. For developing try OpenJDK 17 (tested): `java -version`.
+2. For developing try OpenJDK 21 (tested): `java -version`.
 3. Build ProjectForge:
    `./gradlew build -x test` (or `./gradlew.bat build -x test` on Windows)
 4. Run ProjectForge:
@@ -58,8 +58,8 @@ To configure a different directory you have several options (*choose Your favori
 
 Please note the detailed documentations for administrators, developers as well as for users.
 
-Java version 17 is required since ProjectForge 8.0.
-Please note, that OpenJdk 17 is currently used in production for developing and running ProjectForge.
+Java version 21 is required since ProjectForge 8.1.
+Please note, that OpenJdk 21 is currently used in production for developing and running ProjectForge.
 
 === Quickstart with IntelliJ
 

diff --git a/buildSrc/src/main/kotlin/buildlogic.pf-module-conventions.gradle.kts b/buildSrc/src/main/kotlin/buildlogic.pf-module-conventions.gradle.kts
@@ -18,8 +18,8 @@ group = "org.projectforge"
 version = libs.findVersion("org.projectforge").get().requiredVersion
 
 extensions.configure<JavaPluginExtension> {
-    sourceCompatibility = JavaVersion.VERSION_17
-    targetCompatibility = JavaVersion.VERSION_17
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
 }
 
 tasks.withType<JavaCompile> {

diff --git a/doc/Testinstallation-deutsch.adoc b/doc/Testinstallation-deutsch.adoc
@@ -6,8 +6,8 @@ Die aktuellste Version dieser Datei befindet sich https://github.com/micromata/p
 
 `projectforge-application-8.1-xxx.jar` herunterladen
 
-===== Java 17 installieren
-Open-JDK 17 installieren bzw. entsprechendes Docker-Image verwenden.
+===== Java 21 installieren
+Open-JDK 21 installieren bzw. entsprechendes Docker-Image verwenden.
 
 ==== Erststart
 

diff --git a/plugins/org.projectforge.plugins.banking/build.gradle.kts b/plugins/org.projectforge.plugins.banking/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.datatransfer/build.gradle.kts b/plugins/org.projectforge.plugins.datatransfer/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.ihk/build.gradle.kts b/plugins/org.projectforge.plugins.ihk/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.licensemanagement/build.gradle.kts b/plugins/org.projectforge.plugins.licensemanagement/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.liquidityplanning/build.gradle.kts b/plugins/org.projectforge.plugins.liquidityplanning/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.marketing/build.gradle.kts b/plugins/org.projectforge.plugins.marketing/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.memo/build.gradle.kts b/plugins/org.projectforge.plugins.memo/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.merlin/build.gradle.kts b/plugins/org.projectforge.plugins.merlin/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.skillmatrix/build.gradle.kts b/plugins/org.projectforge.plugins.skillmatrix/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/plugins/org.projectforge.plugins.todo/build.gradle.kts b/plugins/org.projectforge.plugins.todo/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-application/build.gradle.kts b/projectforge-application/build.gradle.kts
@@ -12,7 +12,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-business/build.gradle.kts b/projectforge-business/build.gradle.kts
@@ -9,7 +9,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-carddav/build.gradle.kts b/projectforge-carddav/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-common/build.gradle.kts b/projectforge-common/build.gradle.kts
@@ -13,7 +13,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-commons-test/build.gradle.kts b/projectforge-commons-test/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-jcr/build.gradle.kts b/projectforge-jcr/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-model/build.gradle.kts b/projectforge-model/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-rest/build.gradle.kts b/projectforge-rest/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }
 

diff --git a/projectforge-wicket/build.gradle.kts b/projectforge-wicket/build.gradle.kts
@@ -7,7 +7,7 @@ plugins {
 
 tasks.withType<KotlinCompile> {
     compilerOptions {
-        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_17)
+        jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_21)
     }
 }