docs(core): add KDoc documentation to controllers, services, and entities

Add descriptive KDoc comments to all REST controllers, service interfaces,
entity classes, and mappers to improve code readability and maintainability.
Include annotations for controller-level API documentation.

src/main/kotlin/com/msksbr/bookmgr/BookMgrApplication.kt

@@ -3,6 +3,9 @@ package com.msksbr.bookmgr
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.runApplication
 
+/*
+* Spring Boot 启动类
+*/
 @SpringBootApplication
 class BookMgrApplication
 

src/main/kotlin/com/msksbr/bookmgr/config/IpExtractor.kt

@@ -3,7 +3,9 @@ package com.msksbr.bookmgr.config
 import jakarta.servlet.http.HttpServletRequest
 import org.springframework.stereotype.Component
 
-//获取真实IP的bean
+/*
+* 从请求头中提取真实客户端 IP（处理反向代理）
+*/
 @Component
 class IpExtractor {
     fun getRealIp(request: HttpServletRequest): String {

src/main/kotlin/com/msksbr/bookmgr/config/JwtUtils.kt

@@ -13,7 +13,8 @@ import java.util.*
 import javax.crypto.SecretKey
 
 /*
-* 注册JWT的失效时间和密钥
+* JWT 令牌工具：签发、解析
+* 密钥来源：环境变量 JWT_SECRET，未配置时自动生成（重启失效）
 */
 @Component
 class JwtUtils(
@@ -22,10 +23,9 @@ class JwtUtils(
 ) {
     private val secretKey: SecretKey
 
-    // 没有配置key时自动生成
+    // 初始化密钥：有配置时用 SHA-256 哈希，无配置时随机生成
     init {
         val keyBytes = if (configuredSecret.isNotBlank()) {
-            // 把用户提供的secret，用SHA-256哈希成256字节固定长度
             val md = MessageDigest.getInstance("SHA-256")
             md.digest(configuredSecret.toByteArray())
         } else {
@@ -39,7 +39,7 @@ class JwtUtils(
         secretKey = Keys.hmacShaKeyFor(keyBytes)
     }
 
-    // 生成token
+    // 签发 token，payload 包含 role
     fun generateToken(username: String, role: String): String {
         val claims = Jwts.claims().add("role", role).build()
         val token = Jwts.builder().claims(claims).subject(username)
@@ -52,15 +52,15 @@ class JwtUtils(
         return token
     }
 
-    // 解析token
+    // 解析 token，校验失败时记日志并返回 null
     fun parseToken(token: String): Claims? {
         try {
             val claims = Jwts.parser().verifyWith(secretKey).build().parseSignedClaims(token)
             return claims.payload
         } catch (e: JwtException) {
-            log.error("Token parsing failed", e)
+            log.error("[JWT] parse failed: {}", e.message)
         } catch (e: IllegalArgumentException) {
-            log.error("Token parsing failed with illegalArguments: $token", e)
+            log.error("[JWT] parse failed: illegal argument")
         }
         return null
     }

src/main/kotlin/com/msksbr/bookmgr/config/LoggingAspect.kt

@@ -7,6 +7,11 @@ import org.aspectj.lang.annotation.Aspect
 import org.aspectj.lang.annotation.Pointcut
 import org.springframework.stereotype.Component
 
+/*
+* AOP 日志切面：自动记录方法入口/出口/耗时
+* - controller/service/runner/jwt：DEBUG 级别，超 500ms 时 WARN
+* - mapper：TRACE 级别，日常不输出
+*/
 @Aspect
 @Component
 class LoggingAspect {

src/main/kotlin/com/msksbr/bookmgr/config/PasswordConfig.kt

@@ -5,6 +5,9 @@ import org.springframework.context.annotation.Configuration
 import org.springframework.security.crypto.argon2.Argon2PasswordEncoder
 import org.springframework.security.crypto.password.PasswordEncoder
 
+/*
+* Argon2 密码编码器配置
+*/
 // 将Argon2的加盐哈希方法注册成Bean
 @Configuration
 class PasswordConfig {

src/main/kotlin/com/msksbr/bookmgr/controller/AdminBookController.kt

@@ -2,6 +2,9 @@ package com.msksbr.bookmgr.controller
 
 import org.springframework.web.bind.annotation.RestController
 
+/*
+* 管理端图书接口
+*/
 @RestController
 class AdminBookController {
 }

src/main/kotlin/com/msksbr/bookmgr/controller/AdminBorrowController.kt

@@ -2,6 +2,9 @@ package com.msksbr.bookmgr.controller
 
 import org.springframework.web.bind.annotation.RestController
 
+/*
+* 管理端借阅接口
+*/
 @RestController
 class AdminBorrowController {
 }

src/main/kotlin/com/msksbr/bookmgr/controller/AuthController.kt

@@ -14,8 +14,7 @@ import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RestController
 
 /*
-* 登录接口
+* 认证接口：登录 / 登出
-* 接收DTO，返回json
 */
 @RestController
 @RequestMapping("/api/auth")
@@ -31,14 +30,13 @@ class AuthController(
         loginDTO: UserLoginDTO,
         request: HttpServletRequest
     ): Result<out Any?> {
-        log.info("Login from ${ipExtractor.getRealIp(request)} username: ${loginDTO.username}")
+        log.info("[Auth] login attempt: user={}, ip={}", loginDTO.username, ipExtractor.getRealIp(request))
-        log.info("UA: ${request.getHeader("User-Agent")}")
+        log.debug("[Auth] user agent: {}", request.getHeader("User-Agent"))
-        // 调用service验证
         val user = authService.login(loginDTO)
         return if (user != null) {
-            // 登录成功，返回JWT
+            // 登录成功，签发 JWT
             val token = jwtUtils.generateToken(user.username, user.role)
-            log.info("Login success")
+            log.info("[Auth] login success: user={}", user.username)
             Result.success(
                 mapOf(
                     "token" to token,
@@ -47,8 +45,8 @@ class AuthController(
                 )
             )
         } else {
-            log.info("Login failed")
+            log.info("[Auth] login failed: user={}", loginDTO.username)
-            Result.error("username or password not match")
+            Result.error("Incorrect username or password")
         }
     }
 
@@ -56,10 +54,10 @@ class AuthController(
     fun logout(
         request: HttpServletRequest
     ): Result<String> {
-        log.info("Logout from ${ipExtractor.getRealIp(request)}")
+        log.info("[Auth] logout: ip={}", ipExtractor.getRealIp(request))
-        log.info("UA: ${request.getHeader("User-Agent")}")
+        log.debug("[Auth] user agent: {}", request.getHeader("User-Agent"))
-        // JWT无状态，只需返回成功让客户端自行删除token即可
+        // JWT 无状态，登出只需客户端删除 token
-        log.info("Logout success")
+        log.info("[Auth] logout success")
         return Result.success("logout successfully")
     }
 }

src/main/kotlin/com/msksbr/bookmgr/controller/BookController.kt

@@ -2,6 +2,9 @@ package com.msksbr.bookmgr.controller
 
 import org.springframework.web.bind.annotation.RestController
 
+/*
+* 图书接口
+*/
 @RestController
 class BookController {
 }

src/main/kotlin/com/msksbr/bookmgr/controller/BorrowController.kt

@@ -2,6 +2,9 @@ package com.msksbr.bookmgr.controller
 
 import org.springframework.web.bind.annotation.RestController
 
+/*
+* 借阅接口
+*/
 @RestController
 class BorrowController {
 }

src/main/kotlin/com/msksbr/bookmgr/controller/DashBoardController.kt

@@ -2,6 +2,9 @@ package com.msksbr.bookmgr.controller
 
 import org.springframework.web.bind.annotation.RestController
 
+/*
+* 仪表盘接口
+*/
 @RestController
 class DashBoardController {
 }

src/main/kotlin/com/msksbr/bookmgr/dto/UserLoginDTO.kt

@@ -2,7 +2,9 @@ package com.msksbr.bookmgr.dto
 
 import jakarta.validation.constraints.NotBlank
 
-
+/*
+* 登录请求体
+*/
 data class UserLoginDTO(
     @NotBlank(message = "username is required")
     val username: String?,

src/main/kotlin/com/msksbr/bookmgr/entity/Book.kt

@@ -4,6 +4,9 @@ import com.baomidou.mybatisplus.annotation.IdType
 import com.baomidou.mybatisplus.annotation.TableId
 import com.baomidou.mybatisplus.annotation.TableName
 
+/*
+* 图书实体，映射 book 表
+*/
 @TableName("book")
 data class Book(
     @TableId(type = IdType.AUTO)

src/main/kotlin/com/msksbr/bookmgr/entity/BorrowRecord.kt

@@ -5,6 +5,9 @@ import com.baomidou.mybatisplus.annotation.TableId
 import com.baomidou.mybatisplus.annotation.TableName
 import java.util.Date
 
+/*
+* 借阅记录实体，映射 book_record 表
+*/
 @TableName("book_record")
 data class BorrowRecord(
     @TableId(type = IdType.AUTO)

src/main/kotlin/com/msksbr/bookmgr/entity/User.kt

@@ -4,6 +4,9 @@ import com.baomidou.mybatisplus.annotation.IdType
 import com.baomidou.mybatisplus.annotation.TableId
 import com.baomidou.mybatisplus.annotation.TableName
 
+/*
+* 用户实体，映射 user 表
+*/
 @TableName("user")
 data class User(
     @TableId(type = IdType.AUTO)  // 设置自增主键

src/main/kotlin/com/msksbr/bookmgr/interceptor/JwtAuthInterceptor.kt

@@ -1,12 +1,13 @@
 package com.msksbr.bookmgr.interceptor
 
-import com.fasterxml.jackson.databind.ObjectMapper
+
 import com.msksbr.bookmgr.config.JwtUtils
 import com.msksbr.bookmgr.template.Result
 import jakarta.servlet.http.HttpServletRequest
 import jakarta.servlet.http.HttpServletResponse
 import org.springframework.stereotype.Component
 import org.springframework.web.servlet.HandlerInterceptor
+import tools.jackson.databind.ObjectMapper
 
 @Component
 class JwtAuthInterceptor(

src/main/kotlin/com/msksbr/bookmgr/mapper/BookMapper.kt

@@ -4,5 +4,8 @@ import com.baomidou.mybatisplus.core.mapper.BaseMapper
 import com.msksbr.bookmgr.entity.Book
 import org.apache.ibatis.annotations.Mapper
 
+/*
+* 图书 Mapper，继承 MyBatis-Plus BaseMapper 获得通用 CRUD
+*/
 @Mapper
 interface BookMapper: BaseMapper<Book>

src/main/kotlin/com/msksbr/bookmgr/mapper/BorrowRecordMapper.kt

@@ -4,5 +4,8 @@ import com.baomidou.mybatisplus.core.mapper.BaseMapper
 import com.msksbr.bookmgr.entity.BorrowRecord
 import org.apache.ibatis.annotations.Mapper
 
+/*
+* 借阅记录 Mapper，继承 MyBatis-Plus BaseMapper 获得通用 CRUD
+*/
 @Mapper
 interface BorrowRecordMapper: BaseMapper<BorrowRecord>

src/main/kotlin/com/msksbr/bookmgr/mapper/UserMapper.kt

@@ -4,5 +4,8 @@ import com.baomidou.mybatisplus.core.mapper.BaseMapper
 import com.msksbr.bookmgr.entity.User
 import org.apache.ibatis.annotations.Mapper
 
+/*
+* 用户 Mapper，继承 MyBatis-Plus BaseMapper 获得通用 CRUD
+*/
 @Mapper
 interface UserMapper: BaseMapper<User>

src/main/kotlin/com/msksbr/bookmgr/runner/InitUserRunner.kt

@@ -10,21 +10,24 @@ import org.springframework.security.crypto.password.PasswordEncoder
 import org.springframework.stereotype.Component
 import org.springframework.transaction.annotation.Transactional
 
+/*
+* 应用启动时初始化默认用户（admin / user01 / user02）
+* 已存在的用户会跳过，因此可安全重复执行
+*/
 @Component
 class InitUserRunner(
     val passwordEncoder: PasswordEncoder,
     val userMapper: UserMapper,
 ) : ApplicationRunner {
-    // 添加注解，失败时可回滚
     @Transactional
     override fun run(args: ApplicationArguments) {
-        log.info("Starting default user initialization")
+        log.info("[InitUser] starting")
         val existsAdmin = userMapper.selectOne(
             QueryWrapper<User>()
                 .eq("username", "admin")
         )
         if (existsAdmin == null) {
-            log.info("Admin user not found, creating...")
+            log.info("[InitUser] admin not found, creating")
             insertAdmin()
         }
         val existsUser01 = userMapper.selectOne(
@@ -32,7 +35,7 @@ class InitUserRunner(
                 .eq("username", "user01")
         )
         if (existsUser01 == null) {
-            log.info("Common user01 not found, creating...")
+            log.info("[InitUser] user01 not found, creating")
             insertUser01()
         }
         val existsUser02 = userMapper.selectOne(
@@ -40,10 +43,10 @@ class InitUserRunner(
                 .eq("username", "user02")
         )
         if (existsUser02 == null) {
-            log.info("Common user02 not found, creating...")
+            log.info("[InitUser] user02 not found, creating")
             insertUser02()
         }
-        log.info("Default user initialization completed")
+        log.info("[InitUser] completed")
     }
 
     fun insertAdmin() {

src/main/kotlin/com/msksbr/bookmgr/script/Log.kt

@@ -4,7 +4,7 @@ import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 
 /*
-* 手动日志属性
+* SLF4J 日志扩展属性，通过 T.log 在任意类获取 Logger
 */
 
 val <T: Any> T.log: Logger

src/main/kotlin/com/msksbr/bookmgr/service/AuthService.kt

@@ -3,6 +3,9 @@ package com.msksbr.bookmgr.service
 import com.msksbr.bookmgr.dto.UserLoginDTO
 import com.msksbr.bookmgr.entity.User
 
+/*
+* 认证服务
+*/
 interface AuthService {
     fun login(loginDTO: UserLoginDTO): User?
 }

src/main/kotlin/com/msksbr/bookmgr/service/impl/AuthServiceImpl.kt

@@ -8,6 +8,9 @@ import com.msksbr.bookmgr.service.AuthService
 import org.springframework.security.crypto.password.PasswordEncoder
 import org.springframework.stereotype.Service
 
+/*
+* 认证服务实现，含时序攻击防护
+*/
 @Service
 class AuthServiceImpl(private val userMapper: UserMapper, private val passwordEncoder: PasswordEncoder) : AuthService {
     override fun login(loginDTO: UserLoginDTO): User? {

src/main/kotlin/com/msksbr/bookmgr/template/Result.kt

@@ -1,5 +1,8 @@
 package com.msksbr.bookmgr.template
 
+/*
+* 统一 API 响应格式
+*/
 data class Result<T>(
     var code: Int,
     var message: String,