Revert Java 21 bump and pattern-matching switch; restore Java 17 and if/else instanceof

Co-authored-by: edburns <75821+edburns@users.noreply.github.com>

Author: Copilot

.github/workflows/build-test.yml

@@ -38,7 +38,7 @@ jobs:
           node-version: 22
       - uses: actions/setup-java@v5
         with:
-          java-version: "21"
+          java-version: "17"
           distribution: "temurin"
           cache: "maven"
 

.github/workflows/publish-maven.yml

@@ -53,7 +53,7 @@ jobs:
             - name: Set up JDK 17
               uses: actions/setup-java@v5
               with:
-                  java-version: "21"
+                  java-version: "17"
                   distribution: "temurin"
                   cache: "maven"
                   server-id: central

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 21+](https://img.shields.io/badge/Java-21%2B-blue?logo=openjdk&logoColor=white)](https://openjdk.org/)
+[![Java 17+](https://img.shields.io/badge/Java-17%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 21 or later
+- Java 17 or later
 - GitHub Copilot CLI 0.0.411-1 or later installed and in PATH (or provide custom `cliPath`)
 
 ### Maven

pom.xml

@@ -37,7 +37,7 @@
     </scm>
 
     <properties>
-        <maven.compiler.release>21</maven.compiler.release>
+        <maven.compiler.release>17</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>

src/main/java/com/github/copilot/sdk/CopilotSession.java

@@ -618,33 +618,27 @@ void dispatchEvent(AbstractSessionEvent event) {
      *            the event to handle
      */
     private void handleBroadcastEventAsync(AbstractSessionEvent event) {
-        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);
+        if (event instanceof ExternalToolRequestedEvent toolEvent) {
+            var data = toolEvent.getData();
+            if (data == null || data.requestId() == null || data.toolName() == 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);
+            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);
+
+        } else if (event instanceof PermissionRequestedEvent permEvent) {
+            var data = permEvent.getData();
+            if (data == null || data.requestId() == null || data.permissionRequest() == null) {
+                return;
             }
-            default -> {
-                // Other event types are not handled here
+            PermissionHandler handler = permissionHandler.get();
+            if (handler == null) {
+                return; // This client doesn't handle permissions; another client will
             }
+            executePermissionAndRespondAsync(data.requestId(), data.permissionRequest(), handler);
         }
     }
 

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 21+** installed
+- **Java 17+** 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:

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 21 or later
+- Java 17 or later
 - GitHub Copilot CLI 0.0.411-1 or later installed and in PATH (or provide custom `cliPath`)
 
 ### Installation