ControlSystemStudio · shroffk · May 29, 2026 · May 29, 2026 · May 29, 2026 · May 29, 2026
diff --git a/.travis.yml b/.travis.yml
@@ -2,7 +2,7 @@ sudo: required
 language: java
 dist: xenial
 jdk:
-  - openjdk17
+  - openjdk21
 
 services:
   - xvfb

diff --git a/README.md b/README.md
@@ -8,7 +8,7 @@ https://control-system-studio.readthedocs.io
 
 
 ## Requirements
- - [JDK17 or later, suggested is OpenJDK](https://adoptium.net/en-GB/temurin/archive/?version=17).
+ - [JDK21 or later, suggested is OpenJDK](https://adoptium.net/en-GB/temurin/releases?version=21).
  - [maven 3.x](https://maven.apache.org/) or [ant](http://ant.apache.org/)
 
 
@@ -27,7 +27,7 @@ mvn clean verify -f dependencies/pom.xml
 Define the JAVA_HOME environment variable to point to your Java installation directory. 
 Mac OS users should use something like:
 ```
-export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-17.0.10+7/Contents/Home
+export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-21.0.11+10/Contents/Home
 ```
 Verify through:
 ```
@@ -73,14 +73,14 @@ Download "Eclipse for Java Developers" from https://www.eclipse.org/downloads/pa
 
 Start Eclipse like this:
 
-    export JAVA_HOME=/path/to/your/jdk-17-or-later
+    export JAVA_HOME=/path/to/your/jdk-21-or-later
     export PATH="$JAVA_HOME/bin:$PATH"
     eclipse/eclipse -consoleLog
 
 Check Eclipse Preferences:
 
- * Java, Installed JREs: JDK 17-or-later should be the default
- * Java, Compiler: JDK Compliance should be "9" or higher
+ * Java, Installed JREs: JDK 21-or-later should be the default
+ * Java, Compiler: JDK Compliance should be "21" or higher
 
 
 ### Use plain Java configuration
@@ -112,7 +112,7 @@ In Help/Eclipse Marketplace, search for Maven Integration for Eclipse Luna or ne
 Use File/Import/Maven/Existing Maven Projects to import the phoebus source code.
 
 There can be a compiler error because the "JRE System Library" in the Package Explorer shows "[J2SE-1.4]".
-Right click on the affected projects (greeting-app, probe), Build Path, Configure Build Path, Libraries, Edit the JRE System Library to use the Workspace default (jdk-17).
+Right click on the affected projects (greeting-app, probe), Build Path, Configure Build Path, Libraries, Edit the JRE System Library to use the Workspace default (jdk-21).
 Restart Eclipse IDE.
 
 Can now start product/src/main/java/org.phoebus.product/Launcher.java.
@@ -126,14 +126,14 @@ To import the project:
 * Select the Phoebus directory
 * Import project from external model: Maven
 * Accept the default options and click Next twice
-* Ensure that the JDK is version 11 or above
+ * Ensure that the JDK is version 21 or above
 * Change the project name to Phoebus and click finish
 
 To run the Phoebus application:
 
 * Run | Edit Configurations...
 * Select + | Application
-* Module: Your JRE 17
+ * Module: Your JRE 21
 * Classpath `-cp`: select `product` from drop-down
 * Main class: `org.phoebus.product.Launcher`
 * Set the name to Phoebus

diff --git a/app/alarm/audio-annunciator/pom.xml b/app/alarm/audio-annunciator/pom.xml
@@ -7,10 +7,6 @@
     </parent>
     <artifactId>app-alarm-audio-annunciator</artifactId>
     <name>${project.groupId}:${project.artifactId}</name>
-    <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
-    </properties>
 
     <dependencies>
         <dependency>

diff --git a/app/alarm/freetts-annunciator/pom.xml b/app/alarm/freetts-annunciator/pom.xml
@@ -7,11 +7,6 @@
     </parent>
     <artifactId>app-alarm-freetts-annunciator</artifactId>
   <name>${project.groupId}:${project.artifactId}</name>
-  <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>net.sf.sociaal</groupId>

diff --git a/app/display/actions/pom.xml b/app/display/actions/pom.xml
@@ -12,8 +12,6 @@
     <artifactId>app-display-actions</artifactId>
     <name>${project.groupId}:${project.artifactId}</name>
     <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
     <dependencies>

diff --git a/app/display/linearmeter/pom.xml b/app/display/linearmeter/pom.xml
@@ -10,10 +10,6 @@
 
     <artifactId>app-display-linearmeter</artifactId>
     <name>${project.groupId}:${project.artifactId}</name>
-    <properties>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
-    </properties>
 
     <dependencies>
         <dependency>

diff --git a/app/display/thumbwheel/pom.xml b/app/display/thumbwheel/pom.xml
@@ -5,12 +5,6 @@
         <version>6.0.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
-
-    <properties>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
-    </properties>
-
     <artifactId>app-display-thumbwheel</artifactId>
   <name>${project.groupId}:${project.artifactId}</name>
   <dependencies>

diff --git a/app/queue-server/README.md b/app/queue-server/README.md
@@ -30,7 +30,7 @@ A JavaFX-based client for the [Bluesky QueueServer](https://blueskyproject.io/bl
 
 ### Prerequisites
 
-- **Java 17** or later
+- **Java 21** or later
 - **Maven** (for building from source)
 - **Bluesky Queue Server** running and accessible
 
@@ -107,4 +107,4 @@ When making changes:
 2. Test with both WebSocket and HTTP fallback modes
 3. Verify API key authentication works
 4. Update documentation for new features
-5. Follow existing code style and patterns
+5. Follow existing code style and patterns
diff --git a/app/save-and-restore/util/pom.xml b/app/save-and-restore/util/pom.xml
@@ -8,10 +8,6 @@
 
     <artifactId>save-and-restore-util</artifactId>
   <name>${project.groupId}:${project.artifactId}</name>
-  <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
-    </properties>
 
     <dependencies>
         <dependency>

diff --git a/app/trends/archive-datasource/pom.xml b/app/trends/archive-datasource/pom.xml
@@ -6,12 +6,7 @@
     </parent>
     <modelVersion>4.0.0</modelVersion>
     <artifactId>app-trends-archive-datasource</artifactId>
-  <name>${project.groupId}:${project.artifactId}</name>
-  <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
-    </properties>
-
+    <name>${project.groupId}:${project.artifactId}</name>
     <dependencies>
         <dependency>
             <groupId>org.phoebus</groupId>

diff --git a/app/trends/archive-reader/pom.xml b/app/trends/archive-reader/pom.xml
@@ -7,12 +7,7 @@
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>app-trends-archive-reader</artifactId>
-  <name>${project.groupId}:${project.artifactId}</name>
-  <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
-    </properties>
-
+    <name>${project.groupId}:${project.artifactId}</name>
     <dependencies>
         <dependency>
             <groupId>org.phoebus</groupId>

diff --git a/core/pv-jackie/src/main/java/org/phoebus/pv/jackie/util/SimpleJsonParser.java b/core/pv-jackie/src/main/java/org/phoebus/pv/jackie/util/SimpleJsonParser.java
@@ -29,7 +29,7 @@
  * 
  * <p>
  * This parser has specifically been written in order to minimize the
- * dependencies needed for parsing JSON document. It only uses the Java 17 SE
+ * dependencies needed for parsing JSON document. It only uses the Java SE
  * API and the Apache Commons Lang 3 library.
  * </p>
  * 

diff --git a/pom.xml b/pom.xml
@@ -89,20 +89,21 @@
     <derby.version>10.16.1.1</derby.version>
     <jython.version>2.7.4b1</jython.version>
     <jgit.version>6.9.0.202403050737-r</jgit.version>
-    <maven.compiler.target>17</maven.compiler.target>
+    <maven.compiler.source>21</maven.compiler.source>
+    <maven.compiler.target>21</maven.compiler.target>
     <activemq.client.version>5.18.4</activemq.client.version>
     <commons.compress.version>1.26.1</commons.compress.version>
     <spring.framework.version>5.3.22</spring.framework.version>
-    <spring.boot.version>2.7.3</spring.boot.version>
+    <spring.boot.version>2.7.18</spring.boot.version>
   </properties>
   <build>
     <plugins>
       <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
         <version>3.6.2</version>
         <configuration>
-          <source>17</source>
-          <target>17</target>
+          <source>${maven.compiler.source}</source>
+          <target>${maven.compiler.target}</target>
           <fork>true</fork>
           <compilerArgs>
             <arg>-J--add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED</arg>
@@ -283,7 +284,7 @@
               <configuration>
                 <!-- add this to disable checking -->
                 <doclint>none</doclint>
-                <source>17</source>
+                <source>${maven.compiler.source}</source>
               </configuration>
             </execution>
           </executions>

diff --git a/services/alarm-config-logger/pom.xml b/services/alarm-config-logger/pom.xml
@@ -6,7 +6,7 @@
     <version>6.0.0-SNAPSHOT</version>
   </parent>
   <properties>
-    <java.version>17</java.version>
+    <java.version>21</java.version>
   </properties>
   <artifactId>service-alarm-config-logger</artifactId>
   <name>${project.groupId}:${project.artifactId}</name>
@@ -96,7 +96,7 @@
           <plugin>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-maven-plugin</artifactId>
-            <version>2.7.9</version>
+            <version>${spring.boot.version}</version>
             <executions>
               <execution>
                 <goals>

diff --git a/services/alarm-logger/Dockerfile b/services/alarm-logger/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jre
+FROM eclipse-temurin:21-jre
 
 # deployment unit
 COPY target/service-alarm-logger-*.jar /alarmlogger/service-alarm-logger-*.jar

diff --git a/services/alarm-logger/pom.xml b/services/alarm-logger/pom.xml
@@ -6,7 +6,7 @@
     <version>6.0.0-SNAPSHOT</version>
   </parent>
   <properties>
-    <java.version>17</java.version>
+    <java.version>21</java.version>
     <elasticsearch.version>8.2.0</elasticsearch.version>
   </properties>
   <artifactId>service-alarm-logger</artifactId>
@@ -168,7 +168,7 @@
           <plugin>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-maven-plugin</artifactId>
-            <version>2.7.9</version>
+            <version>${spring.boot.version}</version>
             <executions>
               <execution>
                 <goals>

diff --git a/services/alarm-server/Dockerfile b/services/alarm-server/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jre
+FROM eclipse-temurin:21-jre
 
 # deployment unit
 COPY target/service-alarm-server-*.jar /alarmserver/service-alarm-server-*.jar

diff --git a/services/save-and-restore/Dockerfile b/services/save-and-restore/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jre
+FROM eclipse-temurin:21-jre
 
 # deployment unit
 COPY target/service-save-and-restore-*.jar /saveandrestore/service-save-and-restore-*.jar

diff --git a/services/save-and-restore/README.md b/services/save-and-restore/README.md
@@ -4,7 +4,7 @@ The save-and-restore service implements service as a collection
 of REST endpoints. These can be used by clients to manage configurations (aka save sets) and
 snapshots, to compare snapshots and to restore PV values from snapshots.
 
-The service is packaged as a self-contained Spring Boot jar file. External dependencies are limited to a JVM (Java 17+)
+The service is packaged as a self-contained Spring Boot jar file. External dependencies are limited to a JVM (Java 21+)
 and a running instance of Elasticsearch (8.x).
 
 # Build
@@ -82,4 +82,4 @@ This may be preferable compared to setting environment variables on command line
 ```>export HOST_IP_ADDRESS=1.2.3.4```.
 
 **NOTE:** Accessing IOCs over pva (default mode in the Docker compose files) works **only** if IOC is running on the
-same host as the Docker container. Moreover, this has been verified to work only on Linux.
+same host as the Docker container. Moreover, this has been verified to work only on Linux.
diff --git a/services/save-and-restore/doc/index.rst b/services/save-and-restore/doc/index.rst
@@ -5,7 +5,7 @@ The save-and-restore service implements service as a collection
 of REST endpoints. These can be used by clients to manage configurations (aka save sets) and
 snapshots, to compare snapshots and to restore PV values from snapshots.
 
-The service is packaged as a self-contained Spring Boot jar file. External dependencies are limited to a JVM (Java 17+)
+The service is packaged as a self-contained Spring Boot jar file. External dependencies are limited to a JVM (Java 21+)
 and a running instance of Elasticsearch (8.x).
 
 Running the service

diff --git a/services/save-and-restore/pom.xml b/services/save-and-restore/pom.xml
@@ -232,7 +232,7 @@
 					<plugin>
 						<groupId>org.springframework.boot</groupId>
 						<artifactId>spring-boot-maven-plugin</artifactId>
-						<version>2.7.9</version>
+						<version>${spring.boot.version}</version>
 						<executions>
 							<execution>
 								<goals>

diff --git a/services/scan-server/Dockerfile b/services/scan-server/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:17-jre
+FROM eclipse-temurin:21-jre
 
 # deployment unit
 COPY target/service-scan-server-*.jar /scanserver/service-scan-server-*.jar

diff --git a/services/scan-server/pom.xml b/services/scan-server/pom.xml
@@ -160,7 +160,7 @@
           <plugin>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-maven-plugin</artifactId>
-            <version>2.7.9</version>
+            <version>${spring.boot.version}</version>
             <executions>
               <execution>
                 <goals>