初始提交，未完全测试

template/expr/ast/FieldKeyBuilder.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python3.9
+# -*- coding: utf-8 -*-
+"""
+JFinal FieldKeyBuilder - Field Key Builder
+"""
+
+class FieldKeyBuilder:
+    """Field key builder for field access"""
+    
+    def __init__(self):
+        """Initialize field key builder"""
+        pass
+    
+    def build_field_key(self, field_name: str) -> str:
+        """
+        Build field key
+        
+        Args:
+            field_name: Field name
+            
+        Returns:
+            Field key
+        """
+        return field_name
+    
+    def __repr__(self) -> str:
+        return "FieldKeyBuilder()"