Feat: 实现知识图谱数据库的检索方法，并对外提供接口

backend/handlers/node_handler.go

@@ -8,12 +8,12 @@ import (
 )
 
 type NodeHandler struct {
-	dataService *services.DataService
+	service services.GraphService
 }
 
-func NewNodeHandler(dataService *services.DataService) *NodeHandler {
+func NewNodeHandler(service services.GraphService) *NodeHandler {
 	return &NodeHandler{
-		dataService: dataService,
+		service: service,
 	}
 }
 
@@ -27,7 +27,7 @@ func (h *NodeHandler) GetNodeByID(c *gin.Context) {
 		return
 	}
 
-	node, found := h.dataService.GetNodeByID(nodeID)
+	node, found := h.service.GetNodeByID(nodeID)
 	if !found {
 		c.JSON(http.StatusNotFound, gin.H{
 			"error":   "Not Found",
@@ -49,7 +49,7 @@ func (h *NodeHandler) GetNeighbors(c *gin.Context) {
 		return
 	}
 
-	neighbors, found := h.dataService.GetNeighbors(nodeID)
+	neighbors, found := h.service.GetNeighbors(nodeID)
 	if !found {
 		c.JSON(http.StatusNotFound, gin.H{
 			"error":   "Not Found",