fix: synchronize project JDK runtime selection

src/project-settings/assets/classpath/features/classpathConfigurationViewSlice.ts

@@ -47,6 +47,9 @@ export const classpathConfigurationViewSlice = createSlice({
       },
       loadClasspath: (state, action) => {
         const activeProjectIndex = action.payload.activeProjectIndex;
+        if (action.payload.vmInstalls !== undefined) {
+          state.data.vmInstalls = action.payload.vmInstalls;
+        }
         state.data.output[activeProjectIndex] = action.payload.output;
         state.data.effective.output[activeProjectIndex] = action.payload.output;
 

src/project-settings/assets/classpath/features/components/JdkRuntime.tsx

@@ -5,6 +5,7 @@ import "@vscode-elements/elements/dist/vscode-divider/index.js";
 import "@vscode-elements/elements/dist/vscode-single-select/index.js";
 import "@vscode-elements/elements/dist/vscode-option/index.js";
 import "@vscode-elements/elements/dist/vscode-button/index.js";
+import type { VscodeSingleSelect } from "@vscode-elements/elements/dist/vscode-single-select/index.js";
 
 import { useCallback, useEffect, useRef } from "react";
 import { ClasspathRequest, CommonRequest } from "../../../vscode/utils";
@@ -22,10 +23,11 @@ const JdkRuntime = (): JSX.Element => {
   }, [activeProjectIndex]);
 
   const vmInstalls: VmInstall[] = useSelector((state: any) => state.classpathConfig.data.vmInstalls);
-  const activeVmInstallPath: string = useSelector((state: any) => state.classpathConfig.data.activeVmInstallPath[activeProjectIndex]);
+  const activeVmInstallPath: string = useSelector((state: any) => state.classpathConfig.data.activeVmInstallPath[activeProjectIndex]) ?? "";
+  const hasActiveVmInstall = vmInstalls.some(install => install.path === activeVmInstallPath);
 
   const dispatch = useDispatch();
-  const selectRef = useRef<HTMLElement>(null);
+  const selectRef = useRef<VscodeSingleSelect>(null);
 
   const handleSelectJdk = useCallback((path: string) => {
     if (path === "add-new-jdk") {
@@ -44,21 +46,21 @@ const JdkRuntime = (): JSX.Element => {
   useEffect(() => {
     const el = selectRef.current;
     if (!el) return;
-    const handleChange = (e: Event) => {
-      const selectedValue = (e.target as any).value;
-      if (selectedValue) {
+    const handleChange = () => {
+      const selectedValue = el.value;
+      if (vmInstalls.some(install => install.path === selectedValue)) {
         handleSelectJdk(selectedValue);
       }
     };
     el.addEventListener("change", handleChange);
     return () => el.removeEventListener("change", handleChange);
-  }, [handleSelectJdk]);
+  }, [handleSelectJdk, vmInstalls]);
 
   // Sync the value property on the select element when activeVmInstallPath changes
   useEffect(() => {
     const el = selectRef.current;
-    if (el && activeVmInstallPath) {
-      (el as any).value = activeVmInstallPath;
+    if (el) {
+      el.value = activeVmInstallPath;
     }
   }, [activeVmInstallPath, vmInstalls]);
 
@@ -89,6 +91,11 @@ const JdkRuntime = (): JSX.Element => {
           id="jdk-dropdown"
           className="setting-section-dropdown"
         >
+          {!hasActiveVmInstall && (
+            <vscode-option value={activeVmInstallPath} selected disabled description={activeVmInstallPath}>
+              {activeVmInstallPath ? "Current project JDK (not listed)" : "Project JDK not available"}
+            </vscode-option>
+          )}
           {vmInstalls.map((vmInstall) => (
             <vscode-option
               key={vmInstall.path}
@@ -104,7 +111,14 @@ const JdkRuntime = (): JSX.Element => {
       <div className="jdk-runtime-path">
         {activeVmInstallPath}
       </div>
+      {!hasActiveVmInstall && activeVmInstallPath && (
+        <p>The current project JDK is not in the available runtime list. Refresh JDKs or locate its installation.</p>
+      )}
       <div className="jdk-runtime-actions">
+        <vscode-button secondary onClick={() => ClasspathRequest.onWillListVmInstalls()}>
+          <span className="codicon codicon-refresh mr-1"></span>
+          Refresh JDKs
+        </vscode-button>
         <vscode-button secondary onClick={() => ClasspathRequest.onWillAddNewJdk()}>
           <span className="codicon codicon-folder-opened mr-1"></span>
           Find a local JDK...
@@ -121,7 +135,7 @@ const JdkRuntime = (): JSX.Element => {
 interface OnDidChangeJdkEvent {
   data: {
     command: string;
-    vmInstalls: VmInstall[];
+    vmInstalls?: VmInstall[];
     activeVmInstallPath: string;
   };
 }

src/project-settings/handlers/ClasspathRequestHandler.ts

@@ -14,6 +14,8 @@ export class ClasspathRequestHandler implements vscode.Disposable {
     private webview: vscode.Webview;
     private currentProjectRoot: vscode.Uri | undefined;
     private disposables: vscode.Disposable[] = [];
+    private classpathRequestId = 0;
+    private vmInstallsRequestId = 0;
 
     constructor(webview: vscode.Webview) {
         this.webview = webview;
@@ -69,17 +71,15 @@ export class ClasspathRequestHandler implements vscode.Disposable {
     }
 
     private listVmInstalls = instrumentOperation("projectSettings.classpath.listVmInstalls", async (operationId: string) => {
-        let vmInstalls: VmInstall[] = await this.getVmInstallsFromLS();
-        vmInstalls = vmInstalls.sort((vmA: VmInstall, vmB: VmInstall) => {
-            return vmA.name.localeCompare(vmB.name);
+        const vmInstalls = await this.getVmInstallsFromLS();
+        if (vmInstalls === undefined) {
+            return;
+        }
+        this.webview.postMessage({
+            command: "classpath.onDidListVmInstalls",
+            vmInstalls,
         });
-
-        if (vmInstalls.length > 0) {
-            this.webview.postMessage({
-                command: "classpath.onDidListVmInstalls",
-                vmInstalls,
-            });
-        } else {
+        if (vmInstalls.length === 0) {
             sendInfo(operationId, {
                 vmNumber: vmInstalls.length,
             });
@@ -93,14 +93,24 @@ export class ClasspathRequestHandler implements vscode.Disposable {
             return;
         }
 
+        const requestId = ++this.classpathRequestId;
         const classpath = await this.getProjectClasspathFromLS(uri);
+        if (requestId !== this.classpathRequestId || !this.currentProjectRoot || path.relative(uri.fsPath, this.currentProjectRoot.fsPath)) {
+            return;
+        }
+        // Resolving the project's VM can register a JDK after the initial inventory query.
+        const vmInstalls = await this.getVmInstallsFromLS();
+        if (requestId !== this.classpathRequestId || !this.currentProjectRoot || path.relative(uri.fsPath, this.currentProjectRoot.fsPath)) {
+            return;
+        }
         if (classpath) {
             this.webview.postMessage({
                 command: "classpath.onDidLoadProjectClasspath",
                 projectType: classpath.projectType,
                 sources: classpath.sourcePaths,
                 output: classpath.defaultOutputPath,
                 activeVmInstallPath: classpath.jdkPath,
+                vmInstalls,
                 libraries: classpath.libraries
             });
         }
@@ -310,10 +320,7 @@ export class ClasspathRequestHandler implements vscode.Disposable {
 
         if (result.success) {
             const activeVmInstallPath = result.message;
-            let vmInstalls: VmInstall[] = await this.getVmInstallsFromLS();
-            vmInstalls = vmInstalls.sort((vmA: VmInstall, vmB: VmInstall) => {
-                return vmA.name.localeCompare(vmB.name);
-            });
+            const vmInstalls = await this.getVmInstallsFromLS();
             this.webview.postMessage({
                 command: "classpath.onDidChangeJdk",
                 activeVmInstallPath,
@@ -345,10 +352,7 @@ export class ClasspathRequestHandler implements vscode.Disposable {
 
         if (result.success) {
             const activeVmInstallPath = result.message;
-            let vmInstalls: VmInstall[] = await this.getVmInstallsFromLS();
-            vmInstalls = vmInstalls.sort((vmA: VmInstall, vmB: VmInstall) => {
-                return vmA.name.localeCompare(vmB.name);
-            });
+            const vmInstalls = await this.getVmInstallsFromLS();
             this.webview.postMessage({
                 command: "classpath.onDidChangeJdk",
                 activeVmInstallPath,
@@ -436,13 +440,23 @@ export class ClasspathRequestHandler implements vscode.Disposable {
         });
     });
 
-    private async getVmInstallsFromLS(): Promise<VmInstall[]> {
-        const ret: VmInstall[] = [];
+    private async getVmInstallsFromLS(): Promise<VmInstall[] | undefined> {
+        const requestId = ++this.vmInstallsRequestId;
         try {
-            ret.push(...await vscode.commands.executeCommand<VmInstall[]>("java.execute.workspaceCommand", "java.vm.getAllInstalls") || []);
+            const installs = await vscode.commands.executeCommand<VmInstall[]>("java.execute.workspaceCommand", "java.vm.getAllInstalls") || [];
+            if (requestId !== this.vmInstallsRequestId) {
+                return undefined;
+            }
+            return installs.sort((a, b) => a.name.localeCompare(b.name));
         } catch (error) {
+            if (requestId !== this.vmInstallsRequestId) {
+                return undefined;
+            }
+            const err = error instanceof Error ? error : new Error(String(error));
+            sendError(err);
+            void vscode.window.showErrorMessage(`Unable to load Java runtimes: ${err.message}`);
+            return undefined;
         }
-        return ret;
     }
 
     private async getProjectClasspathFromLS(uri: vscode.Uri): Promise<ClasspathComponent> {

test-plans/java-extension-pack.yaml

@@ -2,6 +2,7 @@
 #
 # Source: wiki Test-Plan.md "Java Extension Pack" scenario
 # Verify: Trigger Java: Configure Classpath command → configuration page appears;
+#         retain the selected project JDK when refreshing the runtime list;
 #         add a project-local JAR to a non-unmanaged project and apply it.
 #
 # Prerequisites:
@@ -14,7 +15,8 @@ name: "Java Extension Pack — Classpath Configuration"
 description: |
   Corresponds to the Java Extension Pack scenario in the wiki Test Plan:
   Trigger the Java: Configure Classpath command, verify the configuration page
-  appears, and cover the non-unmanaged-project Add Library flow.
+  appears, verify the current project JDK remains selected after refreshing
+  available runtimes, and cover the non-unmanaged-project Add Library flow.
 
 setup:
   extension: "redhat.java"
@@ -23,6 +25,9 @@ setup:
   vscodeVersion: "stable"
   workspace: "../../vscode-java/test/resources/projects/eclipse/simple-app"
   timeout: 90
+  settings:
+    java.help.showReleaseNotes: false
+    java.help.firstView: "none"
 
 steps:
   # ── Wait for LS ready ────────────────────────────────────
@@ -59,6 +64,48 @@ steps:
         - "Classpath"
         - "Libraries"
 
+  - id: "open-project-jdk-tab"
+    action: "clickInWebview text=JDK Runtime"
+    verify: "The project JDK tab shows runtime controls and an available current JDK"
+    verifyWebview:
+      contains:
+        - "Refresh JDKs"
+        - "Find a local JDK..."
+      notContains:
+        - "Current project JDK (not listed)"
+        - "Project JDK not available"
+    timeout: 30
+
+  - id: "open-selected-project-jdk"
+    action: "clickInWebview #jdk-dropdown:has(vscode-option[selected]:not([disabled]))"
+    verify: "The dropdown has a real selected runtime option, not an unavailable-current-JDK placeholder"
+    verifyWebview:
+      contains: "Refresh JDKs"
+      notContains: "Current project JDK (not listed)"
+
+  - id: "close-project-jdk-dropdown"
+    action: "clickInWebview #jdk-dropdown"
+
+  - id: "refresh-project-jdks"
+    action: "clickInWebview text=Refresh JDKs"
+    verify: "Refreshing runtimes keeps the current project JDK available without cleaning or restarting"
+    verifyWebview:
+      contains: "Refresh JDKs"
+      notContains:
+        - "Current project JDK (not listed)"
+        - "Project JDK not available"
+    timeout: 30
+
+  - id: "verify-selected-project-jdk-after-refresh"
+    action: "clickInWebview #jdk-dropdown:has(vscode-option[selected]:not([disabled]))"
+    verify: "A real current project JDK is still selected after the inventory refresh"
+    verifyWebview:
+      contains: "Refresh JDKs"
+      notContains: "Current project JDK (not listed)"
+
+  - id: "close-refreshed-project-jdk-dropdown"
+    action: "clickInWebview #jdk-dropdown"
+
   - id: "open-libraries-tab"
     action: "clickInWebview text=Libraries"
     verify: "The Libraries tab is selected and shows library management actions"