fix: 修复若干问题，添加java lsp

backend/cmd/server/main.go

@@ -24,6 +24,7 @@ import (
 	"monica-go-completion-backend/internal/completion"
 	"monica-go-completion-backend/internal/logging"
 	"monica-go-completion-backend/internal/lsp"
+	"monica-go-completion-backend/internal/monitor"
 )
 
 var requestIDSeed atomic.Int64
@@ -235,14 +236,7 @@ func main() {
 		}
 	}
 
-	manager := completion.NewManager(completion.ManagerConfig{
-		WorkspaceDir:    cfg.WorkspaceDir,
-		MaxSessions:     cfg.MaxSessions,
-		SessionTTL:      cfg.SessionTTL,
-		CleanupInterval: cfg.CleanupInterval,
-		InstanceID:      cfg.InstanceID,
-		Registry:        registry,
-	}, cfg.Servers, func(ctx context.Context, spec completion.LanguageServerSpec, workspaceDir string) (completion.RuntimeClient, error) {
+	clientFactory := func(ctx context.Context, spec completion.LanguageServerSpec, workspaceDir string) (completion.RuntimeClient, error) {
 		return lsp.NewClient(ctx, lsp.Config{
 			Command:    spec.Command,
 			Args:       spec.Args,
@@ -250,11 +244,31 @@ func main() {
 			LanguageID: spec.LanguageID,
 			ClientName: "monica-lsp-gateway",
 		})
-	})
+	}
+
+	manager := completion.NewManager(completion.ManagerConfig{
+		WorkspaceDir:    cfg.WorkspaceDir,
+		MaxSessions:     cfg.MaxSessions,
+		SessionTTL:      cfg.SessionTTL,
+		CleanupInterval: cfg.CleanupInterval,
+		InstanceID:      cfg.InstanceID,
+		Registry:        registry,
+	}, cfg.Servers, clientFactory)
 	defer func() {
 		_ = manager.Close()
 	}()
 
+	// 后台预热各语言 LSP 会话，首次请求无需等待冷启动。
+	go manager.WarmUp(context.Background())
+
+	// 后台探测各语言 LSP 可用性（demo 实现：周期性握手探测）。
+	lspStatusMonitor := monitor.NewLSPStatusMonitor(cfg.Servers, cfg.WorkspaceDir, clientFactory, monitor.Config{
+		ProbeInterval:    60 * time.Second,
+		ProbeTimeout:     30 * time.Second,
+		FailureThreshold: 2,
+	})
+	defer lspStatusMonitor.Close()
+
 	// 注册通用中间件与业务路由。
 	router := gin.New()
 	if err := configureProxySettings(router, cfg); err != nil {
@@ -267,8 +281,9 @@ func main() {
 	router.Use(apiTokenMiddleware(cfg.APIToken))
 
 	api.RegisterRoutes(router, manager, api.RouteOptions{
-		RequestTimeout: cfg.RequestTimeout,
-		MaxBodyBytes:   cfg.MaxBodyBytes,
+		RequestTimeout:    cfg.RequestTimeout,
+		MaxBodyBytes:      cfg.MaxBodyBytes,
+		LSPStatusProvider: lspStatusMonitor,
 	})
 
 	server := &http.Server{