devcontainer: Update Java, Maven, and JUnit

.classpath

@@ -13,7 +13,7 @@
 			<attribute name="test" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-11">
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-25">
 		<attributes>
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>

.devcontainer/devcontainer-lock.json

@@ -0,0 +1,9 @@
+{
+  "features": {
+    "ghcr.io/devcontainers/features/java:1": {
+      "version": "1.8.3",
+      "resolved": "ghcr.io/devcontainers/features/java@sha256:61a839211feda1e2a1f10646648a948e733e4d98d770f3a4b6698a3c5fc92abe",
+      "integrity": "sha256:61a839211feda1e2a1f10646648a948e733e4d98d770f3a4b6698a3c5fc92abe"
+    }
+  }
+}

.devcontainer/devcontainer.json

@@ -3,13 +3,13 @@
 {
 	"name": "Java",
 	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
-	"image": "mcr.microsoft.com/devcontainers/java:1-21",
+	"image": "mcr.microsoft.com/devcontainers/java:3-25-trixie",
 
 	"features": {
 		"ghcr.io/devcontainers/features/java:1": {
 			"version": "none",
 			"installMaven": "true",
-			"mavenVersion": "3.8.6",
+			"mavenVersion": "3.10.0",
 			"installGradle": "false"
 		}
 	},

.github/workflows/continuous-integration.yml

@@ -18,7 +18,7 @@ jobs:
         uses: actions/setup-java@de7274f081f381c8f8158605e0321c36c376e2e6 # v6.0.1
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '25'
           check-latest: false
           cache: 'maven'
       - name: Build with Maven

.settings/org.eclipse.jdt.core.prefs

@@ -1,9 +1,9 @@
 eclipse.preferences.version=1
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=11
-org.eclipse.jdt.core.compiler.compliance=11
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=25
+org.eclipse.jdt.core.compiler.compliance=25
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
 org.eclipse.jdt.core.compiler.processAnnotations=disabled
-org.eclipse.jdt.core.compiler.release=disabled
-org.eclipse.jdt.core.compiler.source=11
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=25

README.md

@@ -40,6 +40,12 @@ Follow these steps to open this sample in a container using the VS Code Dev Cont
 
 ## Things to try
 
+### Toolchain
+
+This sample uses Java 25 on Debian 13 (Trixie), Maven 3.10.0, and JUnit Jupiter 6.1.3.
+Run `mvn verify` to compile and test the project, then `java -cp target/classes com.mycompany.app.App` to run it.
+The Maven compiler, editor settings, and CI all target Java 25.
+
 Once you have this sample opened, you'll be able to work with it like you would locally.
 
 Some things to try:

pom.xml

@@ -9,25 +9,28 @@
   <url>https://github.com/microsoft/vscode-remote-try-java</url>
   <dependencies>
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.13.2</version>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>6.1.3</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
   <properties>
-    <jdk.version>11</jdk.version>
-    <maven.compiler.source>11</maven.compiler.source>
-    <maven.compiler.target>11</maven.compiler.target>
+    <maven.compiler.release>25</maven.compiler.release>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
   <build>
     <pluginManagement>
       <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.16.0</version>
+        </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-plugin</artifactId>
-          <version>3.0.0-M6</version>
+          <version>3.6.0</version>
         </plugin>
       </plugins>
     </pluginManagement>

src/test/java/com/mycompany/app/AppTest.java

@@ -1,8 +1,8 @@
 package com.mycompany.app;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 
 public class AppTest {