fix: 修复若干问题，添加java lsp

backend/internal/api/handler.go

@@ -22,10 +22,17 @@ type SessionStatsProvider interface {
 	ActiveSessions() map[string]int
 }
 
+// LSPStatusProvider 暴露按语言的 LSP 探测状态。
+type LSPStatusProvider interface {
+	LspServiceStatus() map[string]any
+}
+
 // RouteOptions 控制 HTTP/WS 接口的超时与请求体上限。
 type RouteOptions struct {
 	RequestTimeout time.Duration // 单次补全调用超时时间。
 	MaxBodyBytes   int64         // 请求体最大字节数（HTTP/WS 共用）。
+	// LSPStatusProvider 可选，用于输出语言服务在线状态。
+	LSPStatusProvider LSPStatusProvider
 }
 
 // RegisterRoutes 注册健康检查、HTTP 补全接口和 WebSocket 补全接口。
@@ -41,6 +48,7 @@ func RegisterRoutes(router *gin.Engine, service CompletionService, options ...Ro
 		if options[0].MaxBodyBytes > 0 {
 			opts.MaxBodyBytes = options[0].MaxBodyBytes
 		}
+		opts.LSPStatusProvider = options[0].LSPStatusProvider
 	}
 
 	router.GET("/health", func(c *gin.Context) {
@@ -62,6 +70,17 @@ func RegisterRoutes(router *gin.Engine, service CompletionService, options ...Ro
 		})
 	})
 
+	router.GET("/health/lsp-status", func(c *gin.Context) {
+		languages := map[string]any{}
+		if opts.LSPStatusProvider != nil {
+			languages = opts.LSPStatusProvider.LspServiceStatus()
+		}
+		c.JSON(http.StatusOK, gin.H{
+			"status":    "ok",
+			"languages": languages,
+		})
+	})
+
 	registerWSRoutes(router, service, opts)
 
 	handleCompletion := func(c *gin.Context) {

backend/internal/api/handler_test.go

@@ -28,6 +28,14 @@ func (f *fakeCompletionService) Complete(_ context.Context, _ completion.Request
 	return f.resp, nil
 }
 
+type fakeLSPStatusProvider struct {
+	status map[string]any
+}
+
+func (f *fakeLSPStatusProvider) LspServiceStatus() map[string]any {
+	return f.status
+}
+
 // 验证 HTTP 补全接口的成功路径。
 func TestRegisterRoutesCompletionSuccess(t *testing.T) {
 	gin.SetMode(gin.TestMode)
@@ -174,3 +182,41 @@ func TestRegisterRoutesCompletionWebSocketSuccess(t *testing.T) {
 		t.Fatalf("unexpected items: %+v", resp.Items)
 	}
 }
+
+// 验证 /health/lsp-status 会返回语言探测状态快照。
+func TestRegisterRoutesLspStatus(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	r := gin.New()
+	RegisterRoutes(r, &fakeCompletionService{}, RouteOptions{
+		LSPStatusProvider: &fakeLSPStatusProvider{
+			status: map[string]any{
+				"go": map[string]any{
+					"online": true,
+				},
+			},
+		},
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/health/lsp-status", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected status 200, got %d", w.Code)
+	}
+
+	var got map[string]any
+	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if got["status"] != "ok" {
+		t.Fatalf("expected status ok, got %#v", got["status"])
+	}
+	languages, ok := got["languages"].(map[string]any)
+	if !ok {
+		t.Fatalf("languages field type mismatch: %#v", got["languages"])
+	}
+	if _, ok := languages["go"]; !ok {
+		t.Fatalf("expected go language status, got %#v", languages)
+	}
+}