Backend Expert Skill (Spring Boot + MyBatis)

This skill provides specialized knowledge for developing and debugging backend services in the RuoYi-Vue ecosystem.

🏗️ Core Principles

• Layered Architecture: Controller -> Service -> Mapper -> XML -> DB.

• RuoYi Conventions:

• Use @PreAuthorize for permission control.

• Use SecurityUtils.getUserId() to get current user securely.

• Use AjaxResult for all Controller returns.

• Use TableDataInfo for pagination returns.

• MyBatis Strictness: XML SQL columns usually use snake_case , Java entities use camelCase . ResultMaps are mandatory for complex queries.

🛠️ Common Workflows

1. Debugging Data Loss (The "Silent Fail")

Context: Frontend sends data, but backend receives null . Checklist:

• JSON Body: Is the Controller method using @RequestBody ?

• Getter/Setters: Does the Domain class have getters/setters for new fields?

• Compilation: CRITICAL. Did the code actually compile? Check for "symbol not found" errors that might be hidden in log files.

• Mapper XML: explicitly map column="user_name" to property="userName" .

2. Controller Pattern

@PreAuthorize("@ss.hasPermi('module:business:add')") @PostMapping public AjaxResult add(@RequestBody MyObject obj) { obj.setCreateBy(SecurityUtils.getUsername()); return toAjax(myService.insert(obj)); }

3. Service Pattern

• Business logic goes here, NOT in Controller.

• Handle transactional logic with @Transactional .

• Verify data uniqueness or integrity before calling Mapper.

How to use

Invoke this skill when adding new API endpoints or Entity fields. It forces you to:

• Verify resultMap in XML.

• Check SecurityUtils usage.

• Confirm strict Data Binding.