Phase 1: 基础框架搭建 🏗️

学习目标: 掌握模块结构、Flyway数据库迁移、BaseServiceImpl继承、MapStruct对象转换

---

📚 学习要点

通过这个阶段，你将学会：

1. ✅ Flyway数据库版本管理 - 如何编写SQL迁移脚本
2. ✅ MyBatis-Plus实体映射 - Entity注解的正确使用
3. ✅ MapStruct对象转换 - 零反射的编译期代码生成
4. ✅ BaseServiceImpl继承 - 复用基础CRUD能力
5. ✅ 统一响应格式 - Result<T>的标准用法
6. ✅ Swagger API文档 - @Schema注解的规范

---

🔧 前置准备

检查模块POM配置

确认 blog-modules/blog-module-comment/pom.xml 包含：

<modules>
    <module>blog-comment-api</module>
    <module>blog-comment-service</module>
</modules>

确认 blog-comment-api/pom.xml 依赖：

<dependencies>
    <dependency>
        <groupId>com.blog</groupId>
        <artifactId>blog-common</artifactId>
    </dependency>
</dependencies>

确认 blog-comment-service/pom.xml 依赖：

<dependencies>
    <dependency>
        <groupId>com.blog</groupId>
        <artifactId>blog-comment-api</artifactId>
    </dependency>
    <dependency>
        <groupId>com.blog</groupId>
        <artifactId>blog-common</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
    </dependency>
</dependencies>

确认 blog-application/pom.xml 添加：

<dependency>
    <groupId>com.blog</groupId>
    <artifactId>blog-comment-service</artifactId>
</dependency>

---

📊 Step 1: 数据库设计（简化版）

创建文件: blog-application/src/main/resources/db/V1.2.0__init_comment_tables.sql

-- ========================================================
-- 文件名: V1.2.0__init_comment_tables.sql
-- 描述: 创建评论表 (Phase 1 简化版)
-- 作者: liusxml
-- 日期: 2025-12-15
-- 版本: 1.2.0
-- ========================================================

USE blog_db;

CREATE TABLE IF NOT EXISTS `cmt_comment` (
    -- 主键
    `id` BIGINT NOT NULL COMMENT '评论ID (主键, 雪花算法)',
    
    -- 关联字段
    `target_type` VARCHAR(20) NOT NULL COMMENT '评论目标类型 (ARTICLE)',
    `target_id` BIGINT NOT NULL COMMENT '目标ID (文章ID)',
    `parent_id` BIGINT NULL COMMENT '父评论ID (NULL表示顶级评论)',
    
    -- 内容字段
    `content` TEXT NOT NULL COMMENT '评论原始内容',
    
    -- 状态字段 (Phase 1 简化，仅一个状态)
    `status` TINYINT(1) NOT NULL DEFAULT 1 COMMENT '状态 (1-已通过)',
    
    -- 统计字段
    `like_count` INT NOT NULL DEFAULT 0 COMMENT '点赞数',
    `reply_count` INT NOT NULL DEFAULT 0 COMMENT '回复数',
    
    -- 审计字段
    `version` INT NOT NULL DEFAULT 1 COMMENT '版本号 (乐观锁)',
    `create_by` BIGINT NOT NULL COMMENT '创建者ID',
    `create_time` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_by` BIGINT NULL COMMENT '更新者ID',
    `update_time` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
    `is_deleted` TINYINT(1) NOT NULL DEFAULT 0 COMMENT '逻辑删除',
    
    -- 索引
    PRIMARY KEY (`id`),
    KEY `idx_target` (`target_type`, `target_id`, `status`),
    KEY `idx_user` (`create_by`, `create_time`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='评论表';

知识点解析:

• Flyway版本号: V1.2.0 - 主版本.次版本.补丁版本
• 雪花算法ID: MyBatis-Plus 自动生成，无需手动指定
• 逻辑删除: is_deleted 配合 @TableLogic 实现软删除
• 乐观锁: version 配合 @Version 防止并发更新冲突

---

📦 Step 2: API模块实现

2.1 创建枚举 - CommentStatus

文件路径: blog-comment-api/src/main/java/com/blog/comment/api/enums/CommentStatus.java

package com.blog.comment.api.enums;

import com.baomidou.mybatisplus.annotation.EnumValue;
import com.fasterxml.jackson.annotation.JsonValue;
import lombok.Getter;

/**
 * 评论状态枚举
 *
 * @author liusxml
 * @since 1.2.0
 */
@Getter
public enum CommentStatus {
    
    APPROVED(1, "已通过");
    
    @EnumValue  // MyBatis-Plus: 数据库存储的值
    private final int code;
    
    @JsonValue  // Jackson: JSON序列化的值
    private final String description;
    
    CommentStatus(int code, String description) {
        this.code = code;
        this.description = description;
    }
}

知识点:

• @EnumValue: MyBatis-Plus 枚举映射，数据库存1而非"APPROVED"
• @JsonValue: JSON响应返回"已通过"而非枚举名

---

2.2 创建枚举 - CommentTargetType

package com.blog.comment.api.enums;

import com.baomidou.mybatisplus.annotation.EnumValue;
import com.fasterxml.jackson.annotation.JsonValue;
import lombok.Getter;

/**
 * 评论目标类型枚举
 */
@Getter
public enum CommentTargetType {
    
    ARTICLE("ARTICLE", "文章");
    
    @EnumValue
    private final String code;
    
    @JsonValue
    private final String description;
    
    CommentTargetType(String code, String description) {
        this.code = code;
        this.description = description;
    }
}

---

2.3 创建 DTO - CommentDTO

文件路径: blog-comment-api/src/main/java/com/blog/comment/api/dto/CommentDTO.java

package com.blog.comment.api.dto;

import com.blog.comment.api.enums.CommentTargetType;
import com.blog.common.base.Identifiable;
import io.swagger.v3.oas.annotations.media.Schema;
import jakarta.validation.constraints.NotBlank;
import jakarta.validation.constraints.NotNull;
import lombok.Data;

import java.io.Serializable;

/**
 * 评论请求DTO
 *
 * @author liusxml
 * @since 1.2.0
 */
@Data
@Schema(description = "评论请求对象")
public class CommentDTO implements Serializable, Identifiable<Long> {
    
    @Schema(description = "评论ID (更新时必填)")
    private Long id;
    
    @NotNull(message = "目标类型不能为空")
    @Schema(description = "评论目标类型", example = "ARTICLE", requiredMode = Schema.RequiredMode.REQUIRED)
    private CommentTargetType targetType;
    
    @NotNull(message = "目标ID不能为空")
    @Schema(description = "目标ID (文章ID)", example = "1", requiredMode = Schema.RequiredMode.REQUIRED)
    private Long targetId;
    
    @Schema(description = "父评论ID (回复评论时填写)", example = "123")
    private Long parentId;
    
    @NotBlank(message = "评论内容不能为空")
    @Schema(description = "评论内容", example = "这篇文章写得很好！", requiredMode = Schema.RequiredMode.REQUIRED)
    private String content;
}

知识点:

• 实现 Identifiable<Long>: 强制要求，BaseServiceImpl 依赖此接口
• @NotBlank vs @NotNull: 字符串用 @NotBlank（非空且非空白），对象用 @NotNull
• @Schema: Swagger 文档注解，提升API可读性

---

2.4 创建 VO - CommentVO

文件路径: blog-comment-api/src/main/java/com/blog/comment/api/vo/CommentVO.java

package com.blog.comment.api.vo;

import com.blog.comment.api.enums.CommentStatus;
import com.blog.comment.api.enums.CommentTargetType;
import io.swagger.v3.oas.annotations.media.Schema;
import lombok.Data;

import java.io.Serializable;
import java.time.LocalDateTime;

/**
 * 评论响应VO
 *
 * @author liusxml
 * @since 1.2.0
 */
@Data
@Schema(description = "评论响应对象")
public class CommentVO implements Serializable {
    
    @Schema(description = "评论ID")
    private Long id;
    
    @Schema(description = "目标类型")
    private CommentTargetType targetType;
    
    @Schema(description = "目标ID")
    private Long targetId;
    
    @Schema(description = "父评论ID")
    private Long parentId;
    
    @Schema(description = "评论内容")
    private String content;
    
    @Schema(description = "状态")
    private CommentStatus status;
    
    @Schema(description = "点赞数")
    private Integer likeCount;
    
    @Schema(description = "回复数")
    private Integer replyCount;
    
    @Schema(description = "评论者ID")
    private Long createBy;
    
    @Schema(description = "评论时间")
    private LocalDateTime createTime;
    
    @Schema(description = "更新时间")
    private LocalDateTime updateTime;
}

---

2.5 创建查询DTO - CommentQueryDTO

package com.blog.comment.api.dto;

import com.blog.comment.api.enums.CommentTargetType;
import io.swagger.v3.oas.annotations.media.Schema;
import lombok.Data;

import java.io.Serializable;

/**
 * 评论查询参数
 */
@Data
@Schema(description = "评论查询参数")
public class CommentQueryDTO implements Serializable {
    
    @Schema(description = "目标类型")
    private CommentTargetType targetType;
    
    @Schema(description = "目标ID")
    private Long targetId;
    
    @Schema(description = "评论者ID")
    private Long createBy;
    
    @Schema(description = "页码", example = "1")
    private Integer pageNum = 1;
    
    @Schema(description = "每页大小", example = "20")
    private Integer pageSize = 20;
}

---

🏛️ Step 3: Service模块实现

3.1 创建 Entity - CommentEntity

文件路径: blog-comment-service/src/main/java/com/blog/comment/domain/entity/CommentEntity.java

package com.blog.comment.domain.entity;

import com.baomidou.mybatisplus.annotation.*;
import com.blog.comment.api.enums.CommentStatus;
import com.blog.comment.api.enums.CommentTargetType;
import lombok.Data;

import java.io.Serializable;
import java.time.LocalDateTime;

/**
 * 评论实体
 *
 * @author liusxml
 * @since 1.2.0
 */
@Data
@TableName("cmt_comment")
public class CommentEntity implements Serializable {
    
    @TableId(type = IdType.ASSIGN_ID)
    private Long id;
    
    private CommentTargetType targetType;
    
    private Long targetId;
    
    private Long parentId;
    
    private String content;
    
    private CommentStatus status;
    
    private Integer likeCount;
    
    private Integer replyCount;
    
    @Version
    private Integer version;
    
    @TableField(fill = FieldFill.INSERT)
    private Long createBy;
    
    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;
    
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Long updateBy;
    
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;
    
    @TableLogic
    private Integer isDeleted;
}

知识点:

• @TableId(type = IdType.ASSIGN_ID): 雪花算法生成19位Long ID
• @Version: 乐观锁版本号，更新时自动+1并校验
• @TableField(fill = ...): 自动填充字段（MybatisPlusHandlerConfig 已配置）
• @TableLogic: 逻辑删除标记，查询时自动添加 is_deleted = 0

---

3.2 创建 Mapper - CommentMapper

文件路径: blog-comment-service/src/main/java/com/blog/comment/infrastructure/mapper/CommentMapper.java

package com.blog.comment.infrastructure.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.blog.comment.domain.entity.CommentEntity;
import org.apache.ibatis.annotations.Mapper;

/**
 * 评论Mapper
 *
 * @author liusxml
 * @since 1.2.0
 */
@Mapper
public interface CommentMapper extends BaseMapper<CommentEntity> {
    // Phase 1: 仅使用 BaseMapper 提供的方法
    // 后续阶段会添加自定义查询
}

---

3.3 创建 Converter - CommentConverter

文件路径: blog-comment-service/src/main/java/com/blog/comment/infrastructure/converter/CommentConverter.java

package com.blog.comment.infrastructure.converter;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.vo.CommentVO;
import com.blog.comment.domain.entity.CommentEntity;
import com.blog.common.base.BaseConverter;
import org.mapstruct.Mapper;
import org.mapstruct.NullValuePropertyMappingStrategy;

/**
 * 评论转换器
 *
 * @author liusxml
 * @since 1.2.0
 */
@Mapper(
    componentModel = "spring",
    nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE
)
public interface CommentConverter extends BaseConverter<CommentDTO, CommentEntity, CommentVO> {
    // MapStruct 自动生成以下方法:
    // - CommentEntity toEntity(CommentDTO dto);
    // - CommentVO toVo(CommentEntity entity);
    // - void updateEntityFromDto(CommentDTO dto, @MappingTarget CommentEntity entity);
}

知识点:

• componentModel = "spring": 生成Spring Bean，支持依赖注入
• nullValuePropertyMappingStrategy.IGNORE: 更新时忽略null值，避免覆盖
• 编译期生成: mvn compile 后在 target/generated-sources/annotations 查看生成代码

---

3.4 创建 Service - ICommentService

文件路径: blog-comment-service/src/main/java/com/blog/comment/service/ICommentService.java

package com.blog.comment.service;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.vo.CommentVO;
import com.blog.comment.domain.entity.CommentEntity;
import com.blog.common.base.IBaseService;

/**
 * 评论服务接口
 *
 * @author liusxml
 * @since 1.2.0
 */
public interface ICommentService extends IBaseService<CommentEntity, CommentVO, CommentDTO> {
    // Phase 1: 仅继承基础CRUD方法
    // 后续阶段会添加业务方法:
    // - List<CommentTreeVO> buildCommentTree(Long targetId);
    // - void approveComment(Long commentId);
    // - void likeComment(Long commentId);
}

---

3.5 创建 ServiceImpl - CommentServiceImpl

文件路径: blog-comment-service/src/main/java/com/blog/comment/service/impl/CommentServiceImpl.java

package com.blog.comment.service.impl;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.enums.CommentStatus;
import com.blog.comment.api.vo.CommentVO;
import com.blog.comment.domain.entity.CommentEntity;
import com.blog.comment.infrastructure.converter.CommentConverter;
import com.blog.comment.infrastructure.mapper.CommentMapper;
import com.blog.comment.service.ICommentService;
import com.blog.common.base.BaseServiceImpl;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.util.Objects;

/**
 * 评论服务实现
 *
 * <p>
 * Phase 1 实现要点:
 * </p>
 * <ul>
 * <li>继承 BaseServiceImpl 获得 CRUD 能力</li>
 * <li>使用构造注入（显式调用super）</li>
 * <li>重写 preSave 钩子设置默认值</li>
 * </ul>
 *
 * @author liusxml
 * @since 1.2.0
 */
@Slf4j
@Service
public class CommentServiceImpl
        extends BaseServiceImpl<CommentMapper, CommentEntity, CommentVO, CommentDTO, CommentConverter>
        implements ICommentService {
    
    /**
     * 构造注入 Converter
     *
     * @param converter MapStruct 转换器
     */
    public CommentServiceImpl(CommentConverter converter) {
        super(converter);
    }
    
    /**
     * 保存前钩子：设置默认值
     *
     * @param entity 评论实体
     */
    @Override
    protected void preSave(CommentEntity entity) {
        // 1. 设置默认状态（Phase 1 简化，直接通过）
        if (Objects.isNull(entity.getStatus())) {
            entity.setStatus(CommentStatus.APPROVED);
        }
        
        // 2. 初始化统计字段
        if (Objects.isNull(entity.getLikeCount())) {
            entity.setLikeCount(0);
        }
        if (Objects.isNull(entity.getReplyCount())) {
            entity.setReplyCount(0);
        }
        
        log.debug("评论保存前处理: status={}, likeCount={}", entity.getStatus(), entity.getLikeCount());
    }
}

知识点:

• 构造注入: 遵循项目规范，使用 @RequiredArgsConstructor 或显式构造
• preSave钩子: BaseServiceImpl提供，在 save() 前自动调用
• Objects.isNull(): Guava 或 Lang3 的空值判断工具

---

3.6 创建 Controller - CommentController

文件路径: blog-comment-service/src/main/java/com/blog/comment/api/controller/CommentController.java

package com.blog.comment.api.controller;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.dto.CommentQueryDTO;
import com.blog.comment.api.vo.CommentVO;
import com.blog.comment.service.ICommentService;
import com.blog.common.exception.BusinessException;
import com.blog.common.exception.SystemErrorCode;
import com.blog.common.model.Result;
import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.tags.Tag;
import jakarta.validation.Valid;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;

import java.io.Serializable;

/**
 * 评论管理 Controller
 *
 * @author liusxml
 * @since 1.2.0
 */
@Slf4j
@RestController
@RequestMapping("/api/v1/comments")
@RequiredArgsConstructor
@Tag(name = "评论管理", description = "评论CRUD接口")
public class CommentController {
    
    private final ICommentService commentService;
    
    /**
     * 创建评论
     *
     * @param dto 评论DTO
     * @return 评论ID
     */
    @PostMapping
    @Operation(summary = "创建评论")
    public Result<Long> create(@Valid @RequestBody CommentDTO dto) {
        Serializable id = commentService.saveByDto(dto);
        return Result.success((Long) id);
    }
    
    /**
     * 获取评论详情
     *
     * @param id 评论ID
     * @return 评论VO
     */
    @GetMapping("/{id}")
    @Operation(summary = "获取评论详情")
    public Result<CommentVO> getById(@PathVariable Long id) {
        return commentService.getVoById(id)
                .map(Result::success)
                .orElseThrow(() -> new BusinessException(SystemErrorCode.NOT_FOUND));
    }
    
    /**
     * 更新评论
     *
     * @param dto 评论DTO
     * @return 是否成功
     */
    @PutMapping
    @Operation(summary = "更新评论")
    public Result<Boolean> update(@Valid @RequestBody CommentDTO dto) {
        return Result.success(commentService.updateByDto(dto));
    }
    
    /**
     * 删除评论
     *
     * @param id 评论ID
     * @return 是否成功
     */
    @DeleteMapping("/{id}")
    @Operation(summary = "删除评论")
    public Result<Boolean> delete(@PathVariable Long id) {
        return Result.success(commentService.removeById(id));
    }
}

知识点:

• @Valid: 触发 DTO 的 @NotNull、@NotBlank 校验
• Optional.orElseThrow(): 优雅的空值处理
• @Tag: Swagger分组标签
• Result.success(): 统一响应格式

---

🧪 Step 4: 测试验证

4.1 单元测试 - CommentServiceImplTest

文件路径: blog-comment-service/src/test/java/com/blog/comment/service/impl/CommentServiceImplTest.java

package com.blog.comment.service.impl;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.enums.CommentStatus;
import com.blog.comment.api.enums.CommentTargetType;
import com.blog.comment.api.vo.CommentVO;
import com.blog.comment.domain.entity.CommentEntity;
import com.blog.comment.infrastructure.converter.CommentConverter;
import com.blog.comment.infrastructure.mapper.CommentMapper;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import java.util.Optional;

import static org.assertj.core.api.Assertions.assertThat;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;

/**
 * 评论服务单元测试
 */
@ExtendWith(MockitoExtension.class)
class CommentServiceImplTest {
    
    @Mock
    private CommentMapper commentMapper;
    
    @Mock
    private CommentConverter commentConverter;
    
    @InjectMocks
    private CommentServiceImpl commentService;
    
    @Test
    void should_createComment_when_validDto() {
        // Given
        CommentDTO dto = new CommentDTO();
        dto.setTargetType(CommentTargetType.ARTICLE);
        dto.setTargetId(1L);
        dto.setContent("测试评论");
        
        CommentEntity entity = new CommentEntity();
        entity.setId(123L);
        
        when(commentConverter.toEntity(any(CommentDTO.class))).thenReturn(entity);
        when(commentMapper.insert(any(CommentEntity.class))).thenReturn(1);
        
        // When
        Long commentId = (Long) commentService.saveByDto(dto);
        
        // Then
        assertThat(commentId).isEqualTo(123L);
        verify(commentMapper, times(1)).insert(any(CommentEntity.class));
    }
    
    @Test
    void should_setDefaultValues_when_preSave() {
        // Given
        CommentEntity entity = new CommentEntity();
        entity.setContent("测试评论");
        
        // When
        commentService.preSave(entity);
        
        // Then
        assertThat(entity.getStatus()).isEqualTo(CommentStatus.APPROVED);
        assertThat(entity.getLikeCount()).isEqualTo(0);
        assertThat(entity.getReplyCount()).isEqualTo(0);
    }
}

---

4.2 集成测试 - CommentControllerTest

package com.blog.comment.api.controller;

import com.blog.comment.api.dto.CommentDTO;
import com.blog.comment.api.enums.CommentTargetType;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilitors.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

/**
 * 评论Controller集成测试
 */
@SpringBootTest
@AutoConfigureMockMvc
class CommentControllerTest {
    
    @Autowired
    private MockMvc mockMvc;
    
    @Autowired
    private ObjectMapper objectMapper;
    
    @Test
    void should_return201_when_createComment() throws Exception {
        CommentDTO dto = new CommentDTO();
        dto.setTargetType(CommentTargetType.ARTICLE);
        dto.setTargetId(1L);
        dto.setContent("集成测试评论");
        
        mockMvc.perform(post("/api/v1/comments")
                .contentType(MediaType.APPLICATION_JSON)
                .content(objectMapper.writeValueAsString(dto)))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.code").value(0))
                .andExpect(jsonPath("$.data").isNumber());
    }
}

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4.3 验证步骤

编译项目

# 在项目根目录执行
mvn clean compile -pl blog-modules/blog-module-comment

运行单元测试

mvn test -pl blog-modules/blog-module-comment/blog-comment-service

启动应用

mvn spring-boot:run -pl blog-application

访问 Swagger UI

打开浏览器: http://localhost:8080/swagger-ui.html

测试以下接口：

1. POST /api/v1/comments - 创建评论
2. GET /api/v1/comments/{id} - 查询评论
3. PUT /api/v1/comments - 更新评论
4. DELETE /api/v1/comments/{id} - 删除评论

---

✅ Phase 1 完成检查清单

• 数据库表创建成功（验证: DESCRIBE cmt_comment;）
• Flyway迁移记录存在（SELECT * FROM flyway_schema_history WHERE version='1.2.0';）
• 枚举类编译通过
• DTO/VO添加了所有必需注解
• Entity使用了正确的MyBatis-Plus注解
• Converter生成了实现类（check target/generated-sources）
• Service继承了BaseServiceImpl
• Controller返回Result<T>
• 单元测试全部通过
• Swagger UI可访问并能成功调用接口

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💡 关键知识点总结

知识点	核心概念	实际作用
Flyway	数据库版本控制	自动执行SQL脚本，支持回滚
@TableId(ASSIGN_ID)	雪花算法ID生成	分布式唯一ID，无需数据库自增
@Version	乐观锁	防止并发更新冲突
@TableLogic	逻辑删除	DELETE 变 UPDATE is_deleted=1
Identifiable<T>	ID接口	BaseServiceImpl依赖，强制实现
BaseServiceImpl	CRUD基类	复用80%代码，仅写业务逻辑
MapStruct	编译期代码生成	零反射，性能优于BeanUtils
@Valid	JSR-303校验	自动校验@NotNull/@NotBlank
Result<T>	统一响应	标准化API返回格式

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🎯 下一步

Phase 1完成后，你已经掌握了：

• ✅ 从0到1搭建完整模块
• ✅ 理解项目的分层架构
• ✅ 熟悉MyBatis-Plus和MapStruct

准备进入 Phase 2: 树形结构实现 🌲，学习：

• Materialized Path 算法
• 递归查询优化
• 树形数据组装