Refactor handleBroadcastEventAsync to use Java 21 pattern matching switch; bump minimum Java to 21

Copilot · edburns · Copilot · commit c67265bfa532 · 2026-03-10T15:22:36.000Z
Co-authored-by: edburns &lt;75821+edburns@users.noreply.github.com&gt;
diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
@@ -38,7 +38,7 @@ jobs:
           node-version: 22
       - uses: actions/setup-java@v5
         with:
-          java-version: "17"
+          java-version: "21"
           distribution: "temurin"
           cache: "maven"
 
diff --git a/.github/workflows/publish-maven.yml b/.github/workflows/publish-maven.yml
@@ -53,7 +53,7 @@ jobs:
             - name: Set up JDK 17
               uses: actions/setup-java@v5
               with:
-                  java-version: "17"
+                  java-version: "21"
                   distribution: "temurin"
                   cache: "maven"
                   server-id: central
diff --git a/README.md b/README.md
@@ -4,7 +4,7 @@
 [![Site](https://github.com/copilot-community-sdk/copilot-sdk-java/actions/workflows/deploy-site.yml/badge.svg)](https://github.com/copilot-community-sdk/copilot-sdk-java/actions/workflows/deploy-site.yml)
 [![Coverage](.github/badges/jacoco.svg)](https://copilot-community-sdk.github.io/copilot-sdk-java/snapshot/jacoco/index.html)
 [![Documentation](https://img.shields.io/badge/docs-online-brightgreen)](https://copilot-community-sdk.github.io/copilot-sdk-java/)
-[![Java 17+](https://img.shields.io/badge/Java-17%2B-blue?logo=openjdk&logoColor=white)](https://openjdk.org/)
+[![Java 21+](https://img.shields.io/badge/Java-21%2B-blue?logo=openjdk&logoColor=white)](https://openjdk.org/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
 #### Latest release
@@ -24,7 +24,7 @@ Java SDK for programmatic control of GitHub Copilot CLI, enabling you to build A
 
 ### Requirements
 
-- Java 17 or later
+- Java 21 or later
 - GitHub Copilot CLI 0.0.411-1 or later installed and in PATH (or provide custom `cliPath`)
 
 ### Maven
diff --git a/pom.xml b/pom.xml
@@ -37,7 +37,7 @@
     </scm>
 
     <properties>
-        <maven.compiler.release>17</maven.compiler.release>
+        <maven.compiler.release>21</maven.compiler.release>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <!-- Directory where the copilot-sdk repo will be cloned for tests -->
         <copilot.sdk.clone.dir>${project.build.directory}/copilot-sdk</copilot.sdk.clone.dir>
diff --git a/src/main/java/com/github/copilot/sdk/CopilotSession.java b/src/main/java/com/github/copilot/sdk/CopilotSession.java
@@ -618,27 +618,33 @@ void dispatchEvent(AbstractSessionEvent event) {
      *            the event to handle
      */
     private void handleBroadcastEventAsync(AbstractSessionEvent event) {
-        if (event instanceof ExternalToolRequestedEvent toolEvent) {
-            var data = toolEvent.getData();
-            if (data == null || data.requestId() == null || data.toolName() == null) {
-                return;
-            }
-            ToolDefinition tool = getTool(data.toolName());
-            if (tool == null) {
-                return; // This client doesn't handle this tool; another client will
+        switch (event) {
+            case ExternalToolRequestedEvent toolEvent -> {
+                var data = toolEvent.getData();
+                if (data == null || data.requestId() == null || data.toolName() == null) {
+                    return;
+                }
+                ToolDefinition tool = getTool(data.toolName());
+                if (tool == null) {
+                    return; // This client doesn't handle this tool; another client will
+                }
+                executeToolAndRespondAsync(data.requestId(), data.toolName(), data.toolCallId(), data.arguments(),
+                        tool);
             }
-            executeToolAndRespondAsync(data.requestId(), data.toolName(), data.toolCallId(), data.arguments(), tool);
-
-        } else if (event instanceof PermissionRequestedEvent permEvent) {
-            var data = permEvent.getData();
-            if (data == null || data.requestId() == null || data.permissionRequest() == null) {
-                return;
+            case PermissionRequestedEvent permEvent -> {
+                var data = permEvent.getData();
+                if (data == null || data.requestId() == null || data.permissionRequest() == null) {
+                    return;
+                }
+                PermissionHandler handler = permissionHandler.get();
+                if (handler == null) {
+                    return; // This client doesn't handle permissions; another client will
+                }
+                executePermissionAndRespondAsync(data.requestId(), data.permissionRequest(), handler);
             }
-            PermissionHandler handler = permissionHandler.get();
-            if (handler == null) {
-                return; // This client doesn't handle permissions; another client will
+            default -> {
+                // Other event types are not handled here
             }
-            executePermissionAndRespondAsync(data.requestId(), data.permissionRequest(), handler);
         }
     }
 
diff --git a/src/site/markdown/getting-started.md b/src/site/markdown/getting-started.md
@@ -18,7 +18,7 @@ Copilot: In Tokyo it's 75°F and sunny. Great day to be outside!
 
 Before you begin, make sure you have:
 
-- **Java 17+** installed
+- **Java 21+** installed
 - **GitHub Copilot CLI** installed and authenticated ([Installation guide](https://docs.github.com/en/copilot/how-tos/set-up/install-copilot-cli))
 
 Verify the CLI is working:
diff --git a/src/site/markdown/index.md b/src/site/markdown/index.md
@@ -8,7 +8,7 @@ Welcome to the documentation for the **Copilot SDK for Java** — a Java SDK for
 
 ### Requirements
 
-- Java 17 or later
+- Java 21 or later
 - GitHub Copilot CLI 0.0.411-1 or later installed and in PATH (or provide custom `cliPath`)
 
 ### Installation
