init

src/main/kotlin/Program.kt

@@ -0,0 +1,29 @@
+import ddd.application.DefaultUserService
+import ddd.application.dto.ChangeUsername
+import ddd.domain.service.ExistsUserDomainService
+import ddd.infrastructure.repository.MemoryUserRepository
+import ddd.infrastructure.verification.EmailVerificationService
+import mvc.controllers.UserController
+import mvc.dao.UserRepository
+import mvc.entities.User
+import mvc.services.UserSimpleService
+
+//fun main() {
+//    val controller = UserController(UserSimpleService(UserRepository()))
+//    val changeUsername = controller.changeUsername(User(1L, "nian", "3"))
+//    println(changeUsername)
+//}
+
+fun main() {
+    val memoryUserRepository = MemoryUserRepository()
+
+    val userController = ddd.controller.UserController(
+        DefaultUserService(
+            memoryUserRepository,
+            EmailVerificationService(),
+            ExistsUserDomainService(memoryUserRepository)
+        )
+    )
+    val changeUsername = userController.changeUsername(ChangeUsername(1L, "nian", "po",""))
+    println(changeUsername)
+}

src/main/kotlin/ddd/application/DefaultUserService.kt

@@ -0,0 +1,27 @@
+package ddd.application
+
+import ddd.application.dto.ChangeUsername
+import ddd.domain.User
+import ddd.domain.port.VerificationService
+import ddd.domain.repository.UserRepository
+import ddd.domain.service.ExistsUserDomainService
+import ddd.domain.valueobject.Username
+import shared.exceptions.NotFoundException
+
+class DefaultUserService(
+    val userRepository: UserRepository,
+    val verificationService: VerificationService,
+    val existsUserDomainService: ExistsUserDomainService,
+) : UserService {
+    override fun changeUsername(userDto: ChangeUsername): User {
+        val user = userRepository.findById(userDto.id) ?: throw NotFoundException("User with id ${userDto.id} not found")
+        user.changeUsername(
+            Username(userDto.firstName, userDto.lastName),
+            userDto.verificationCode,
+            verificationService,
+            existsUserDomainService
+        )
+        userRepository.save(user)
+        return user
+    }
+}

src/main/kotlin/ddd/application/UserService.kt

@@ -0,0 +1,8 @@
+package ddd.application
+
+import ddd.application.dto.ChangeUsername
+import ddd.domain.User
+
+interface UserService {
+    fun changeUsername(userDto: ChangeUsername): User
+}

src/main/kotlin/ddd/application/dto/ChangeUsername.kt

@@ -0,0 +1,3 @@
+package ddd.application.dto
+
+data class ChangeUsername(val id: Long ,val firstName: String, val lastName: String, val verificationCode: String)

src/main/kotlin/ddd/controller/UserController.kt

@@ -0,0 +1,9 @@
+package ddd.controller
+
+import ddd.application.UserService
+import ddd.application.dto.ChangeUsername
+
+
+class UserController(val service: UserService) {
+    fun changeUsername(changeUsername: ChangeUsername) = service.changeUsername(changeUsername)
+}

src/main/kotlin/ddd/domain/User.kt

@@ -0,0 +1,74 @@
+package ddd.domain
+
+import ddd.domain.entity.UserRank
+import ddd.domain.valueobject.UserId
+import ddd.domain.valueobject.UserStatusEnum
+import ddd.domain.valueobject.Username
+import ddd.domain.port.VerificationService
+import ddd.domain.service.ExistsUserDomainService
+import ddd.domain.validation.changeUsername.EmailVerificationValidation
+import ddd.domain.validation.changeUsername.ExistsUsernameValidation
+import ddd.domain.validation.changeUsername.RankPolicyValidation
+import ddd.domain.validation.changeUsername.TimeIntervalValidation
+import ddd.domain.validation.changeUsername.UsernameChangeContext
+import shared.exceptions.ChangeUsernameException
+import shared.validation.ValidationChain
+import java.time.Clock
+import java.time.LocalDateTime
+
+class User(
+    val id: UserId,
+    var username: Username,
+    var status: UserStatusEnum,
+    var lastUsernameChange: LocalDateTime?,
+    var rank: UserRank,
+) {
+    // 领域方法：修改用户名（入口点）
+    fun changeUsername(
+        newUsername: Username,
+        verificationCode: String,
+        verificationService: VerificationService,
+        existsUserService: ExistsUserDomainService,
+        clock: Clock = Clock.systemDefaultZone()
+    ) {
+        validateState()
+        validateChangeUsername(newUsername, verificationCode, verificationService, existsUserService, clock)
+        executeUsernameChange(newUsername, clock)
+    }
+
+    private fun validateState() {
+        if (status != UserStatusEnum.ACTIVE) {
+            throw ChangeUsernameException("用户未激活")
+        }
+    }
+
+    private fun validateChangeUsername(
+        newUsername: Username,
+        verificationCode: String,
+        verificationService: VerificationService,
+        existsUserService: ExistsUserDomainService,
+        clock: Clock
+    ) {
+        val context = UsernameChangeContext(
+            user = this,
+            newUsername = newUsername,
+            verificationCode = verificationCode,
+            clock = clock,
+            verificationService = verificationService,
+            existsUserService = existsUserService
+        )
+
+        // 组合验证规则（责任链模式）
+        ValidationChain<UsernameChangeContext>()
+            .add(EmailVerificationValidation())
+            .add(RankPolicyValidation())
+            .add(TimeIntervalValidation())
+            .add(ExistsUsernameValidation())
+            .validate(context)
+    }
+
+    private fun executeUsernameChange(newUsername: Username, clock: Clock) {
+        username = newUsername
+        lastUsernameChange = LocalDateTime.now(clock)
+    }
+}

src/main/kotlin/ddd/domain/entity/InternalUserRankPolicy.kt

@@ -0,0 +1,11 @@
+package ddd.domain.entity
+
+import ddd.domain.User
+
+class InternalUserRankPolicy : UserRankPolicy {
+    override fun canChangeUsername(user: User) = true
+
+    override fun requiresEmailVerification() = false
+
+    override fun getMaxChangeIntervalDays() = 0
+}

src/main/kotlin/ddd/domain/entity/RegularUserRankPolicy.kt

@@ -0,0 +1,10 @@
+package ddd.domain.entity
+
+import ddd.domain.User
+
+class RegularUserRankPolicy : UserRankPolicy {
+    override fun canChangeUsername(user: User) = false
+    override fun requiresEmailVerification() = false
+    override fun getMaxChangeIntervalDays() = Int.MAX_VALUE
+}
+

src/main/kotlin/ddd/domain/entity/UserRank.kt

@@ -0,0 +1,32 @@
+package ddd.domain.entity
+
+import ddd.domain.valueobject.UserRankEnum
+
+sealed interface UserRank {
+    val value: UserRankEnum
+    val policy: UserRankPolicy
+
+    class RegularUserRank() : UserRank {
+        override val value: UserRankEnum = UserRankEnum.REGULAR
+        override val policy = RegularUserRankPolicy()
+        override fun toString(): String {
+            return value.toString()
+        }
+    }
+
+    class VipUserRank() : UserRank {
+        override val value: UserRankEnum = UserRankEnum.VIP
+        override val policy = VipUserRankPolicy()
+        override fun toString(): String {
+            return value.toString()
+        }
+    }
+
+    class InternalUserRank() : UserRank {
+        override val value: UserRankEnum = UserRankEnum.INTERNAL
+        override val policy = InternalUserRankPolicy()
+        override fun toString(): String {
+            return value.toString()
+        }
+    }
+}

src/main/kotlin/ddd/domain/entity/UserRankPolicy.kt

@@ -0,0 +1,9 @@
+package ddd.domain.entity
+
+import ddd.domain.User
+
+interface UserRankPolicy {
+    fun canChangeUsername(user: User): Boolean
+    fun requiresEmailVerification(): Boolean
+    fun getMaxChangeIntervalDays(): Int
+}

src/main/kotlin/ddd/domain/entity/VipUserRankPolicy.kt

@@ -0,0 +1,9 @@
+package ddd.domain.entity
+
+import ddd.domain.User
+
+class VipUserRankPolicy : UserRankPolicy {
+    override fun canChangeUsername(user: User) = true
+    override fun requiresEmailVerification() = true
+    override fun getMaxChangeIntervalDays() = 30
+}

src/main/kotlin/ddd/domain/port/VerificationService.kt

@@ -0,0 +1,8 @@
+package ddd.domain.port
+
+import ddd.domain.valueobject.UserId
+
+interface VerificationService {
+    fun isVerified(userId: UserId, code: String): Boolean
+    fun sendVerificationCode(userId: UserId)
+}

src/main/kotlin/ddd/domain/repository/UserRepository.kt

@@ -0,0 +1,14 @@
+package ddd.domain.repository
+
+import ddd.domain.User
+import ddd.domain.valueobject.Username
+
+interface UserRepository {
+    fun save(user: User)
+
+    fun findById(id: Long): User?
+
+    fun findByUsername(username: Username): User?
+
+    fun update(user: User)
+}

src/main/kotlin/ddd/domain/service/ExistsUserDomainService.kt

@@ -0,0 +1,10 @@
+package ddd.domain.service
+
+import ddd.domain.repository.UserRepository
+import ddd.domain.valueobject.Username
+
+class ExistsUserDomainService(val userRepository: UserRepository) {
+    fun existsByUsername(username: Username): Boolean{
+        return userRepository.findByUsername(username) != null
+    }
+}

src/main/kotlin/ddd/domain/validation/changeUsername/EmailVerificationValidation.kt

@@ -0,0 +1,17 @@
+package ddd.domain.validation.changeUsername
+
+import shared.exceptions.ChangeUsernameException
+import shared.validation.AbstractValidationHandler
+
+class EmailVerificationValidation : AbstractValidationHandler<UsernameChangeContext>() {
+    override fun validate(context: UsernameChangeContext) {
+        if(context.user.rank.policy.requiresEmailVerification()){
+            val emailVerified = context.verificationService.isVerified(context.user.id, context.verificationCode)
+            if (emailVerified) {
+                throw ChangeUsernameException("验证码错误")
+            }
+        }
+
+        next(context)
+    }
+}

src/main/kotlin/ddd/domain/validation/changeUsername/ExistsUsernameValidation.kt

@@ -0,0 +1,13 @@
+package ddd.domain.validation.changeUsername
+
+import shared.exceptions.ChangeUsernameException
+import shared.validation.AbstractValidationHandler
+
+class ExistsUsernameValidation : AbstractValidationHandler<UsernameChangeContext>() {
+    override fun validate(context: UsernameChangeContext) {
+        require(!context.existsUserService.existsByUsername(context.newUsername)) {
+            throw ChangeUsernameException("用户名已存在")
+        }
+        next(context)
+    }
+}

src/main/kotlin/ddd/domain/validation/changeUsername/RankPolicyValidation.kt

@@ -0,0 +1,13 @@
+package ddd.domain.validation.changeUsername
+
+import shared.exceptions.ChangeUsernameException
+import shared.validation.AbstractValidationHandler
+
+class RankPolicyValidation : AbstractValidationHandler<UsernameChangeContext>()  {
+    override fun validate(context: UsernameChangeContext) {
+        require (context.user.rank.policy.canChangeUsername(context.user)) {
+            throw ChangeUsernameException("用户${context.user.id}没有权限修改用户名")
+        }
+        next(context)
+    }
+}

src/main/kotlin/ddd/domain/validation/changeUsername/TimeIntervalValidation.kt

@@ -0,0 +1,21 @@
+package ddd.domain.validation.changeUsername
+
+import shared.exceptions.ChangeUsernameException
+import shared.validation.AbstractValidationHandler
+import java.time.Duration
+import java.time.LocalDateTime
+
+class TimeIntervalValidation : AbstractValidationHandler<UsernameChangeContext>() {
+    override fun validate(context: UsernameChangeContext) {
+        val lastChange = context.user.lastUsernameChange
+        val policy = context.user.rank.policy
+        
+        lastChange?.let { 
+            val daysBetween = Duration.between(it, LocalDateTime.now(context.clock)).toDays()
+            if (daysBetween < policy.getMaxChangeIntervalDays()) {
+                throw ChangeUsernameException("30天内禁止重复修改")
+            }
+        }
+        next(context) // 传递至下一个验证器
+    }
+}

src/main/kotlin/ddd/domain/validation/changeUsername/UsernameChangeContext.kt

@@ -0,0 +1,16 @@
+package ddd.domain.validation.changeUsername
+
+import ddd.domain.User
+import ddd.domain.port.VerificationService
+import ddd.domain.service.ExistsUserDomainService
+import ddd.domain.valueobject.Username
+import java.time.Clock
+
+data class UsernameChangeContext(
+    val user: User,
+    val newUsername: Username,
+    val verificationCode: String,
+    val clock: Clock,
+    val verificationService: VerificationService,
+    val existsUserService: ExistsUserDomainService
+)

src/main/kotlin/ddd/domain/valueobject/UserId.kt

@@ -0,0 +1,3 @@
+package ddd.domain.valueobject
+
+data class UserId(val value: Long)

src/main/kotlin/ddd/domain/valueobject/UserRankEnum.kt

@@ -0,0 +1,5 @@
+package ddd.domain.valueobject
+
+enum class UserRankEnum {
+    REGULAR, VIP, INTERNAL
+}

src/main/kotlin/ddd/domain/valueobject/UserStatusEnum.java

@@ -0,0 +1,5 @@
+package ddd.domain.valueobject;
+
+public enum UserStatusEnum {
+    ACTIVE,DEACTIVATED,BANNED
+}

src/main/kotlin/ddd/domain/valueobject/Username.kt

@@ -0,0 +1,14 @@
+package ddd.domain.valueobject
+
+data class Username(val firstName: String, val lastName: String) {
+    override fun toString(): String {
+        return "$firstName $lastName"
+    }
+
+    val regex = Regex("^[a-zA-Z0-9_]+$")
+
+    init {
+        require(toString().length in 4..20) { "用户名长度需在4-20之间" }
+        require(regex.matches(firstName) && regex.matches(lastName)) { "包含非法字符" }
+    }
+}

src/main/kotlin/ddd/infrastructure/repository/MemoryUserRepository.kt

@@ -0,0 +1,40 @@
+package ddd.infrastructure.repository
+
+import ddd.domain.User
+import ddd.domain.entity.UserRank
+import ddd.domain.repository.UserRepository
+import ddd.domain.valueobject.UserId
+import ddd.domain.valueobject.UserStatusEnum
+import ddd.domain.valueobject.Username
+
+class MemoryUserRepository : UserRepository {
+    val users = mutableMapOf<Long, User>()
+
+    init {
+        save(
+            User(
+                UserId(1L),
+                Username("nian", "chen"),
+                UserStatusEnum.ACTIVE,
+                null,
+                UserRank.RegularUserRank()
+            )
+        )
+    }
+
+    override fun save(user: User) {
+        users += user.id.value to user
+    }
+
+    override fun findById(id: Long): User? {
+        return users[id]
+    }
+
+    override fun findByUsername(username: Username): User? {
+        return users.entries.find { it.value.username == username }?.value
+    }
+
+    override fun update(user: User) {
+        users[user.id.value] = user
+    }
+}

src/main/kotlin/ddd/infrastructure/verification/EmailVerificationService.kt

@@ -0,0 +1,9 @@
+package ddd.infrastructure.verification
+
+import ddd.domain.port.VerificationService
+import ddd.domain.valueobject.UserId
+
+class EmailVerificationService : VerificationService {
+    override fun isVerified(userId: UserId, code: String) = true
+    override fun sendVerificationCode(userId: UserId) = println("sending verification email")
+}

src/main/kotlin/mvc/controllers/UserController.kt

@@ -0,0 +1,8 @@
+package mvc.controllers
+
+import mvc.entities.User
+import mvc.services.UserService
+
+class UserController(val service: UserService) {
+    fun changeUsername(user: User) = service.changeUsername(user)
+}

src/main/kotlin/mvc/dao/UserRepository.kt

@@ -0,0 +1,23 @@
+package mvc.dao
+
+import mvc.entities.User
+
+class UserRepository {
+    val users = mutableMapOf<Long, User>()
+
+    init {
+        add(User(1L, "nian", "chen"))
+    }
+
+    fun add(user: User) {
+        users += user.id to user
+    }
+
+    fun findById(id: Long): User? {
+        return users[id]
+    }
+
+    fun update(user: User) {
+        users[user.id] = user
+    }
+}

src/main/kotlin/mvc/entities/User.kt

@@ -0,0 +1,7 @@
+package mvc.entities
+
+data class User (
+    val id: Long,
+    val firstName: String,
+    val lastName: String
+)

src/main/kotlin/mvc/services/UserComplexService.kt

@@ -0,0 +1,18 @@
+package mvc.services
+
+import shared.exceptions.NotFoundException
+import mvc.dao.UserRepository
+import mvc.entities.User
+
+
+class UserComplexService(
+    val repository: UserRepository
+) : UserService {
+    // 用户
+    override fun changeUsername(user: User): User {
+        val findUser = repository.findById(user.id) ?: throw NotFoundException("User ${user.id} not found")
+        val copy = findUser.copy(firstName = user.firstName, lastName = user.lastName)
+        repository.update(copy)
+        return copy
+    }
+}

src/main/kotlin/mvc/services/UserService.kt

@@ -0,0 +1,7 @@
+package mvc.services
+
+import mvc.entities.User
+
+interface UserService {
+    fun changeUsername(user: User): User
+}

src/main/kotlin/mvc/services/UserSimpleService.kt

@@ -0,0 +1,14 @@
+package mvc.services
+
+import shared.exceptions.NotFoundException
+import mvc.dao.UserRepository
+import mvc.entities.User
+
+class UserSimpleService(val repository: UserRepository) : UserService {
+    override fun changeUsername(user: User): User {
+        val findUser = repository.findById(user.id) ?: throw NotFoundException("User ${user.id} not found")
+        val copy = findUser.copy(firstName = user.firstName, lastName = user.lastName)
+        repository.update(copy)
+        return copy
+    }
+}

src/main/kotlin/shared/exceptions/ChangeUsernameException.kt

@@ -0,0 +1,4 @@
+package shared.exceptions
+
+class ChangeUsernameException(msg: String) : RuntimeException(msg) {
+}

src/main/kotlin/shared/exceptions/NotFoundException.kt

@@ -0,0 +1,4 @@
+package shared.exceptions
+
+class NotFoundException(msg: String) : RuntimeException(msg) {
+}

src/main/kotlin/shared/validation/AbstractValidationHandler.kt

@@ -0,0 +1,15 @@
+package shared.validation
+
+abstract class AbstractValidationHandler<T> : ValidationHandler<T> {
+    private lateinit var nextHandler: ValidationHandler<T>
+
+    override fun setNext(handler: ValidationHandler<T>) {
+        nextHandler = handler
+    }
+
+    protected fun next(context: T) {
+        if (::nextHandler.isInitialized) {
+            nextHandler.validate(context)
+        }
+    }
+}

src/main/kotlin/shared/validation/ValidationChain.kt

@@ -0,0 +1,22 @@
+package shared.validation
+
+class ValidationChain<T> {
+    private var firstHandler: ValidationHandler<T>? = null
+    private var lastHandler: ValidationHandler<T>? = null
+
+    fun add(handler: ValidationHandler<T>): ValidationChain<T> {
+        if (firstHandler == null) {
+            firstHandler = handler
+            lastHandler = handler
+        } else {
+            lastHandler?.setNext(handler)
+            lastHandler = handler
+        }
+        return this
+    }
+
+    fun validate(context: T) {
+        firstHandler?.validate(context)
+            ?: throw IllegalStateException("验证链未初始化")
+    }
+}

src/main/kotlin/shared/validation/ValidationHandler.kt

@@ -0,0 +1,6 @@
+package shared.validation
+
+interface ValidationHandler<T> {
+    fun validate(context: T)
+    fun setNext(handler: ValidationHandler<T>)
+}