refactor(appserver): close 改为关自持 ExecutorService——HttpClient.close() 为 JDK 21 API，与 2.0.x 线保持实现一致；测试助手 readTree 统一包裹异常

Author: loong10k

src/main/java/io/github/easy4j/codex/appserver/CodexAppServerClient.java

@@ -20,6 +20,8 @@
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import tools.jackson.databind.DeserializationFeature;
 import tools.jackson.databind.ObjectMapper;
@@ -72,6 +74,11 @@ public class CodexAppServerClient implements AutoCloseable {
             JsonMapper.builder().disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).build();
     private final ThreadMappingCache threadBySession;
     private final Object httpClientLock = new Object();
+    private final ExecutorService clientExecutor = Executors.newCachedThreadPool(r -> {
+        Thread thread = new Thread(r, "codex-app-server-client");
+        thread.setDaemon(true);
+        return thread;
+    });
 
     private volatile HttpClient httpClient;
     private volatile boolean closed;
@@ -145,16 +152,15 @@ public CodexAppServerConfig getConfig() {
     }
 
     /**
-     * Closes the client. New turns are rejected afterwards; the shared
-     * {@link HttpClient} is shut down once any in-flight turn completes.
+     * Closes the client. New turns are rejected afterwards; the executor
+     * backing the shared {@link HttpClient} is shut down gracefully. The
+     * executor is owned by this client so closing works on every JDK line
+     * ({@code HttpClient.close()} only exists since JDK 21).
      */
     @Override
     public void close() {
         closed = true;
-        HttpClient client = httpClient;
-        if (Objects.nonNull(client)) {
-            client.close();
-        }
+        clientExecutor.shutdown();
     }
 
     private HttpClient httpClient() {
@@ -164,6 +170,7 @@ private HttpClient httpClient() {
                 if (Objects.isNull(httpClient)) {
                     httpClient = HttpClient.newBuilder()
                             .connectTimeout(Duration.ofMillis(config.getConnectTimeoutMillis()))
+                            .executor(clientExecutor)
                             .build();
                 }
                 client = httpClient;

src/test/java/io/github/easy4j/codex/appserver/CodexAppServerClientE2ETest.java

@@ -123,8 +123,12 @@ void shouldCompleteTurnWithoutSessionKey() throws Exception {
     }
 
     private String methodOf(String frame) {
-        JsonNode node = mapper.readTree(frame);
-        return node.path("method").asText("");
+        try {
+            JsonNode node = mapper.readTree(frame);
+            return node.path("method").asText("");
+        } catch (Exception ex) {
+            throw new IllegalStateException("Invalid JSON-RPC frame: " + frame, ex);
+        }
     }
 
     private List<String> methodsOf(FakeCodexAppServer server) {

src/test/java/io/github/easy4j/codex/appserver/CodexAppServerTurnTest.java

@@ -48,7 +48,11 @@ private CodexAppServerTurn newTurn(AppServerTurnRequest request, ThreadMappingCa
     }
 
     private JsonNode lastFrame(List<String> sent) {
-        return mapper.readTree(sent.get(sent.size() - 1));
+        try {
+            return mapper.readTree(sent.get(sent.size() - 1));
+        } catch (Exception ex) {
+            throw new IllegalStateException("Invalid captured frame", ex);
+        }
     }
 
     @Test