【WEB 系列】SpringBoot 集成 Mybatis-Plus-工具盒子

概述 {#概述}

目标:MybatisPlus, 为简化 Mybatis 开发而生, 只做增强, 不做改变

简介 {#简介}

MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。简单来说就是简化 JDBC 操作

愿景

我们的愿景是成为 MyBatis 最好的搭档，就像魂斗罗中的 1P、2P，基友搭配，效率翻倍。

特性 {#特性}

无侵入：只做增强不做改变，引入它不会对现有工程产生影响，如丝般顺滑
损耗小：启动即会自动注入基本 CURD，性能基本无损耗，直接面向对象操作
强大的 CRUD 操作：内置通用 Mapper、通用 Service，仅仅通过少量配置即可实现单表大部分 CRUD 操作，更有强大的条件构造器，满足各类使用需求
支持 Lambda 形式调用：通过 Lambda 表达式，方便的编写各类查询条件，无需再担心字段写错
支持主键自动生成：支持多达 4 种主键策略（内含分布式唯一 ID 生成器 - Sequence），可自由配置，完美解决主键问题
支持 ActiveRecord 模式：支持 ActiveRecord 形式调用，实体类只需继承 Model 类即可进行强大的 CRUD 操作
支持自定义全局通用操作：支持全局通用方法注入（ Write once, use anywhere ）
内置代码生成器：采用代码或者 Maven 插件可快速生成 Mapper 、 Model 、 Service 、 Controller 层代码，支持模板引擎，更有超多自定义配置等您来使用
内置分页插件：基于 MyBatis 物理分页，开发者无需关心具体操作，配置好插件之后，写分页等同于普通 List 查询
分页插件支持多种数据库：支持 MySQL、MariaDB、Oracle、DB2、H2、HSQL、SQLite、Postgre、SQLServer 等多种数据库
内置性能分析插件：可输出 Sql 语句以及其执行时间，建议开发测试时启用该功能，能快速揪出慢查询
内置全局拦截插件：提供全表 delete 、 update 操作智能分析阻断，也可自定义拦截规则，预防误操作

支持的数据库 {#支持的数据库}

几乎包含市面上所有主流数据库

mysql 、 mariadb 、 oracle 、 db2 、 h2 、 hsql 、 sqlite 、 postgresql 、 sqlserver 、 presto
达梦数据库、虚谷数据库、人大金仓数据库

框架结构 {#框架结构}

快速开始 {#快速开始}

官方地址:传送门

核心步骤:

使用第三方组件:

导入对应的依赖

研究依赖如何配置

代码如何编写

提高扩展技术能力

创建表

DROP TABLE IF EXISTS USER;
CREATE TABLE USER (
	id BIGINT ( 20 ) NOT NULL COMMENT '主键 ID',
	NAME VARCHAR ( 30 ) NULL DEFAULT NULL COMMENT '姓名',
	age INT ( 11 ) NULL DEFAULT NULL COMMENT '年龄',
	email VARCHAR ( 50 ) NULL DEFAULT NULL COMMENT '邮箱',
	PRIMARY KEY ( id ) 
);
DELETE FROM USER;
INSERT INTO USER ( id, NAME, age, email )
VALUES
	( 1, 'Jone', 18, 'test1@baomidou.com' ),
	( 2, 'Jack', 20, 'test2@baomidou.com' ),
	( 3, 'Tom', 28, 'test3@baomidou.com' ),
	( 4, 'Sandy', 21, 'test4@baomidou.com' ),
	( 5, 'Billie', 24, 'test5@baomidou.com' );
-- 真实开发中，version（乐观锁）、deleted（逻辑删除）、gmt_create、gmt_modified

创建 spring-boot 项目, 导入依赖, 初始化项目

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- 简化实体类 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--MySQL 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.43</version>
        </dependency>
        <!--mybatis-plus 启动器 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>
        <!--spring-boot-test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
</dependencies>

注意: 在使用 mybatis-plus 可以简化我们大量的代码, 不可以在同一个项目下导入 mybatis 依赖和 mybatis-plus, 会有版本冲突!!!

配置数据库连接相关内容

# MySQL5
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/index
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: root
# MySQL8 配置
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis_plus?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root

注意:

MySQL5 和 MySQL8 驱动不同

MySQL-5:com.mysql.jdbc.Driver

MySQL-8:com.mysql.cj.jdbc.Driver

MySQL8 需要增加时区配置serverTimezone=GMT%2B8

创建实体类

@Getter
@Setter
@ToString
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

创建 dao 接口

/**
 * Software：IntelliJ IDEA 2020.1 x64
 * Author: MoBai·杰
 * Date: 2020/6/8 14:05
 * ClassName:UserDao
 * 使用 mybatis-plus, 每个 mapper 接口都需要继承 BaseMapper
 * BaseMapper 类描述： Mapper 继承该接口后，无需编写 mapper.xml 文件，即可获得 CRUD 功能
 */
@Repository // 表示持久层
public interface UserDao extends BaseMapper<User> {
}

全局启动类添加 扫描 mapper 接口

/**
 * 全局启动类
 */
// 表示扫描 mapper 包下的所有接口
@MapperScan("com.mobai.mybatis_plus.dao")
@SpringBootApplication
public class MybatisPlusApplication {

    <span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token class-name">String</span><span class="token punctuation">[</span><span class="token punctuation">]</span> args<span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">SpringApplication</span><span class="token punctuation">.</span><span class="token function">run</span><span class="token punctuation">(</span><span class="token class-name">MybatisPlusApplication</span><span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">,</span> args<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>



}

测试类

@SpringBootTest
class MybatisPlusApplicationTests {

    <span class="token comment">// 注入 Dao 接口, 继承 BaseMapper</span>
    <span class="token annotation punctuation">@Autowired</span>
    <span class="token keyword">private</span> <span class="token class-name">UserDao</span> userDao<span class="token punctuation">;</span>

    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">void</span> <span class="token function">contextLoads</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token comment">// 调用 BaseMapper 查询方法 &lt;selectList&gt;</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectList</span><span class="token punctuation">(</span><span class="token keyword">null</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        list<span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>



}

效果

思考 {#思考}

SQL 是谁帮我们写的?

Mybatis-plus 帮我们写好了

方法哪里来的?

Mybatis-plus 帮我们写的

配置日志输出 {#配置日志输出}

yml 配置添加日志处理

# 配置日志输出 使用默认控制台打印
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

测试

插入测试和雪花算法 {#插入测试和雪花算法}

添加

/**
 * 添加数据
 */
@Test
public void testInsert() {
    User user = new User();
    user.setName("墨白君");
    user.setAge(25);
    user.setEmail("mobaijun8@163.com");
    // mybatis-plus 会自动帮助我们生成主键 ID
    int insert = userDao.insert(user);
    // 被影响的行数
    System.out.println("insert =" + insert);
    // ID 会自动回填
    System.out.println("user =" + user);
}

数据库插入的 ID 是全局唯一 ID

主键生成策略 {#主键生成策略}

mybats-plus默认策略为: ID_WORKER

扩展: 分布式系统唯一 ID 生成:传送门

雪花算法 {#雪花算法}

Twitter 的 snowflake 算法

snowflake 是 Twitter 开源的分布式 ID 生成算法，结果是一个 long 型的 ID。其核心思想是：使用 41bit 作为毫秒数，10bit 作为机器的 ID（5 个 bit 是数据中心，5 个 bit 的机器 ID），12bit 作为毫秒内的流水号（意味着每个节点在每毫秒可以产生 4096 个 ID），最后还有一个符号位，永远是 0。以上实现思路基本可以保证主键 ID 为全球唯一

Mybatis-Plus 提供的所有策略 {#Mybatis-Plus 提供的所有策略}

看IdType源码

public enum IdType {
    /**
     * 数据库 ID 自增
     */
    AUTO(0),
    /**
     * 该类型为未设置主键类型
     */
    NONE(1),
    /**
     * 用户输入 ID
     * 该类型可以通过自己注册自动填充插件进行填充
     */
    INPUT(2),

    <span class="token comment">/* 以下 3 种类型、只有当插入对象 ID 为空，才自动填充。 */</span>
    <span class="token comment">/**
     * 全局唯一 ID (idWorker)
     */</span>
    <span class="token function">ID_WORKER</span><span class="token punctuation">(</span><span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
    <span class="token comment">/**
     * 全局唯一 ID (UUID)
     */</span>
    <span class="token function">UUID</span><span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
    <span class="token comment">/**
     * 字符串全局唯一 ID (idWorker 的字符串表示)
     */</span>
    <span class="token function">ID_WORKER_STR</span><span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">)</span><span class="token punctuation">;</span>



}

不同的主键策略测试 {#不同的主键策略测试}

IdType.AUTO: 主键自增长

数据表添加自增长策略

-- 已有数据表添加自增策略
ALTER TABLE `user` CHANGE id LONG NOT NULL AUTO_INCREMENT PRIMARY KEY;

实体类添加 主键自增长策略

@Getter
@Setter
@ToString
public class User {
    // 常见的主键生成策略(UUID/MySQL 自增长 / 雪花算法 /redis/zookeeper...)
    @TableId(type = IdType.AUTO)
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

测试 / 查看日志

/**
 * 添加数据
 */
@Test
public void testInsert() {
    User user = new User();
    user.setName("墨白");
    user.setAge(21);
    user.setEmail("mobaijun8@163.com");
    // mybatis-plus 会自动帮助我们生成主键 ID
    int insert = userDao.insert(user);
    // 被影响的行数
    System.out.println("insert =" + insert);
    // ID 会自动回填
    System.out.println("user =" + user);
}

查看数据表是否自增

更新操作 {#更新操作}

测试类

/**
 * 根据 ID 修改操作
 */
@Test
public void testUpdate() {
    User user = new User();
    user.setId(1269882840871374849L);
    user.setName("小柠檬");
    user.setEmail("mobaijun8@163.com");
    // 根据用户 ID 修改
    int i = userDao.updateById(user);
    System.out.println("i =" + i);
}

注意:updateById()名字虽然是 ById, 但源码里面的参数是一个对象!!!

注意:Mybatis-Plus 会通过条件帮我们自动拼接动态 SQL, 比mybatis 手动编写动态 SQL 标签灵活

结果

自动填充处理 {#自动填充处理}

比如一些测试log, 创建时间和修改时间, 这些操作一般都是通过自动化完成的, 一般我们不希望手动操作!!!

扩展: 阿里巴巴开发手册规定: 所有的数据库表都要包含两个字段:gmt_create和gmt_modified, 几乎所有的表都要配置上, 并且需要自动化

自动填充有两种方式

方式一: 数据库级别 {#方式一 - 数据库级别}

-- 已有数据表添加新字段
alter table user add gmt_create date; -- 开始时间
alter table user add gmt_modified date; -- 结束时间

实体类添加属性

@Getter
@Setter
@ToString
public class User {
    // 常见的主键生成策略(UUID/MySQL 自增长 / 雪花算法 /redis/zookeeper...)
    @TableId(type = IdType.AUTO)
    private Long id;
    private String name;
    private Integer age;
    private String email;
    // 开始时间
    private Date gmtCreate;
    // 结束时间
    private Date gmrModified;
}

测试

/**
 * 添加数据
 */
@Test
public void testInsert() {
    User user = new User();
    user.setName("框架师");
    user.setAge(21);
    user.setEmail("mobaijun8@163.com");
    // mybatis-plus 会自动帮助我们生成主键 ID
    int insert = userDao.insert(user);
    // 被影响的行数
    System.out.println("insert =" + insert);
    // ID 会自动回填
    System.out.println("user =" + user);
}

方式二: 代码级别 {#方式二 - 代码级别}

字段添加填充内容

// 开始时间
// 插入填充字段
@TableField(fill = FieldFill.INSERT)
private Date gmtCreate;
// 结束时间
// 更新填充字段
@TableField(fill = FieldFill.INSERT_UPDATE)
private Date gmtModified;

源码内容

public enum FieldFill {
    /**
     * 默认不处理
     */
    DEFAULT,
    /**
     * 插入填充字段
     */
    INSERT,
    /**
     * 更新填充字段
     */
    UPDATE,
    /**
     * 插入和更新填充字段
     */
    INSERT_UPDATE
}

创建自定义元对象处理器接口

@Slf4j // 添加日志
@Component // 注入 Spring 容器中
public class MyMetaObjectHandler implements MetaObjectHandler {
    /**
     * 插入时的填充策略
     *
     * @param metaObject
     */
    @Override
    public void insertFill(MetaObject metaObject) {
        // 添加日志
        log.info("start insert fill............");
        /**
         * String fieldName: 需要插入的字段
         * Object fieldVal: 需要插入的类型
         * MetaObject metaObject: 需要给那个数据处理
         */
        this.setFieldValByName("gmtCreate", new Date(), metaObject);
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }

    <span class="token comment">/**
     * 更新时的填充策略
     *
     * @param metaObject
     */</span>
    <span class="token annotation punctuation">@Override</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">updateFill</span><span class="token punctuation">(</span><span class="token class-name">MetaObject</span> metaObject<span class="token punctuation">)</span> <span class="token punctuation">{</span>
        log<span class="token punctuation">.</span><span class="token function">info</span><span class="token punctuation">(</span><span class="token string">"end update fill............"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">/**
         * 更新的时候只需要更新的字段
         */</span>
        <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">setFieldValByName</span><span class="token punctuation">(</span><span class="token string">"gmtModified"</span><span class="token punctuation">,</span> <span class="token keyword">new</span> <span class="token class-name">Date</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> metaObject<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>



}

自定义元对象处理器接口必须要实现 MetaObjectHandler 接口

测试

/**
 * 添加数据
 */
@Test
public void testInsert() {
    User user = new User();
    user.setName("小狐狸");
    user.setAge(21);
    user.setEmail("mobaijun@163.com");
    // mybatis-plus 会自动帮助我们生成主键 ID
    int insert = userDao.insert(user);
    // 被影响的行数
    System.out.println("insert =" + insert);
    // ID 会自动回填
    System.out.println("user =" + user);
}

乐观锁处理 {#乐观锁处理}

乐观锁 : 故名思意十分乐观，它总是认为不会出现问题，无论干什么不去上锁！如果出现了问题，再次更新值测试

悲观锁：故名思意十分悲观，它总是认为总是出现问题，无论干什么都会上锁！再去操作！

乐观锁实现方式：
- 取出记录时，获取当前 version
- 更新时，带上这个 version
- 执行更新时， set version = newVersion where version = oldVersion
- 如果 version 不对，就更新失败

乐观锁：1、先查询，获得版本号 version = 1
-- A
update user set name = "kuangshen", version = version + 1
where id = 2 and version = 1
-- B 线程抢先完成，这个时候 version = 2，会导致 A 修改失败！
update user set name = "kuangshen", version = version + 1
where id = 2 and version = 1

在数据库中添加 version 字段

实体类

// 配置乐观锁插件
@Version // 乐观锁注解
private Integer version;

新建 config 包, 创建 MyBatisPlusConfig 配置类

/**
 * Software：IntelliJ IDEA 2020.1 x64
 * Author: MoBai·杰
 * Date: 2020/6/8 16:52
 * ClassName:MyBatisPlusConfig
 * 类描述： Spring 配置类
 */
// 表示扫描 mapper 包下的所有接口
@MapperScan("com.mobai.mybatis_plus.dao")
@EnableTransactionManagement // 开启自动事务
@Configuration // 表示这个类是全局配置类
public class MyBatisPlusConfig {

    <span class="token comment">/**
     * 注册乐观锁插件
     *
     * @return
     */</span>
    <span class="token annotation punctuation">@Bean</span>
    <span class="token keyword">public</span> <span class="token class-name">OptimisticLockerInterceptor</span> <span class="token function">optimisticLockerInterceptor</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token keyword">return</span> <span class="token keyword">new</span> <span class="token class-name">OptimisticLockerInterceptor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>



}

乐观锁成功测试

/**
 * 测试乐观锁成功
 */
@Test
public void testOptimisticLocker() {
    // 1. 查询用户信息
    User user = userDao.selectById(1L);
    // 2. 修改用户信息
    user.setName("墨白科技");
    user.setEmail("mobaijun8@163.com");
    user.setAge(21);
    // 3. 执行更新
    userDao.updateById(user);
}

# 控制台打印 sql
UPDATE user SET name=?, age=?, email=?, version=?, gmt_create=?, gmt_modified=? WHERE id=? AND version=?

乐观锁失败测试

/**
 * 测试乐观锁失败！多线程下
 */
@Test
public void testOptimisticLocker2() {
    /**
     * 线程 1
     */
    User user = userDao.selectById(1L);
    user.setName("墨白科技 111");
    user.setEmail("mobaijun8@163.com");
    user.setAge(21);
    /**
     * 线程 2
     * 模拟另外一个线程执行了插队操作
     */
    User user2 = userDao.selectById(1L);
    user2.setName("墨白科技 222");
    user2.setEmail("mobaijun8@163.com");
    user2.setAge(21);
    userDao.updateById(user2);
    // 自旋锁来多次尝试提交！
    userDao.updateById(user); // 如果没有乐观锁就会覆盖插队线程的值！
}

查询操作 {#查询操作}

/**
 * 测试查询
 */
@Test
public void testSelectById() {
    User id = userDao.selectById(1L);
    System.out.println("id =" + id);
}

/**




* 批量查询
  */
  @Test
  public void testSelectByBatchId() {
  List<User> users = userDao.selectBatchIds(Arrays.asList(1, 2, 3));
  System.out.println("users =" + users);
  }




/**

`
`
* `按条件查询
  */``
  `@Test`
  `public` `void` `testSelectByBatchIdS()` `{`
  `HashMap<String, Object>` map `=` `new` `HashMap<>();`
  `// 自定义条件`
  map`.put("name",` `"Jack");`
  map`.put("age",` `20);`
  `List<User>` users `=` userDao`.selectByMap(`map`);`
  users`.forEach(System.`out`::println);`
  `}

分页查询 {#分页查询}

应用场景: 分页在浏览场景或一些 web 网站非常常见

常用的分页方式
- 使用 MySQL 原始 limit 进行分页
- Mybatis插件PageHelper
- MybatisPlus其实也内置了分页插件
配置拦截器组件即可

/**
 * 分页拦截器
 *
 * @return
 */
@Bean
public PaginationInterceptor paginationInterceptor() {
    // 开启 count 的 join 优化, 只针对部分 left join
    return new PaginationInterceptor();
}

测试: 直接使用 Page 对象即可！

/**
 * 测试分页查询
 */
@Test
public void testPage() {
    /**
     * 参数一: 当前页
     * 参数一: 页大小
     * 使用了分页插件以后, 所有的分页操作也变得非常简单
     */
    Page<User> page = new Page<>(2, 4);
    // 调用 selectPage 进行分页
    userDao.selectPage(page, null);
    page.getRecords().forEach(System.out::println);
    // 获取记录总数
    System.out.println("page =" + page.getTotal());
}

删除操作 {#删除操作}

/**
 * 测试删除
 */
@Test
public void testDeleteById() {
    userDao.deleteById(1269882840871374854L);
}
/**
 * 批量删除
 */
@Test
public void testDeleteList() {
    userDao.deleteBatchIds(Arrays.asList(1269882840871374853L,
            1269882840871374852L,
            1269882840871374851L,
            1269882840871374850L,
            1269882840871374849L));
}
/**
 * 通过集合删除
 */
@Test
public void testDeleteMap() {
    HashMap<String, Object> map = new HashMap<>();
    map.put("name", "墨白科技 222");
    userDao.deleteByMap(map);
}

逻辑删除 {#逻辑删除}

物理删除：从数据库中直接移除

逻辑删除：在数据库中没有被移除，而是通过一个变量来让他失效！ deleted = 0 => deleted = 1

管理员可以查看被删除的记录！防止数据的丢失，类似于回收站！

在表中新增一个字段 deleted 逻辑删除

实体类

// 逻辑删除
@TableLogic // 逻辑删除注解
private Integer deleted;

在 MyBatisPlusConfig 添加逻辑删除组件

/**
 * 逻辑删除组件
 */
@Bean
public ISqlInjector sqlInjector() {
    return new LogicSqlInjector();
}

yml配置逻辑删除

# 配置逻辑删除 
global-config:
  db-config:
    logic-delete-value: 1
    logic-not-delete-value: 0

测试

/**
 * 逻辑删除
 * 相当于回收站
 */
@Test
public void testDeleted() {
    userDao.deleteById(6L);
}

数据库字段值变为0

记录依旧在数据库，但是值确已经变化了！

性能分析插件 {#性能分析插件}

我们在平时的开发中，会遇到一些慢 sql。测试！ druid,,,,,

作用：性能分析拦截器，用于输出每条 SQL 语句及其执行时间

MP 也提供性能分析插件，如果超过这个时间就停止运行！

MyBatisPlusConfig导入插件

/**
 * SQL 执行效率插件
 */
@Bean
@Profile({"dev", "test"}) // 设置 dev test 环境开启, 保证开发效率
public PerformanceInterceptor performanceInterceptor() {
    PerformanceInterceptor performanceInterceptor =
            new PerformanceInterceptor();
    // 设置执行时间和写入日志
    Properties properties = new Properties();
    properties.setProperty("format", "true");
    // 设置 SQL 执行时间和写入日志
    performanceInterceptor.setProperties(properties);
    return performanceInterceptor;
}

第二种写法(单独配置)

// 设置 SQL 最大执行时间, 如果超过了则不执行
performanceInterceptor.setMaxTime(10);
// 设置 SQL 是否格式化
performanceInterceptor.setFormat(true);

application.yml配置插件

# 数据库配置
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/index?characterEncoding=utf-8
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: root
  # 设置性能分析插件  
  profiles:
    active: dev

测试

/**
 * 测试性能分析插件
 */
@Test
public void contextLoads2() {
    List<User> users = userDao.selectList(null);
    users.forEach(System.out::println);
}

使用性能分析插件，可以帮助我们提高效率！

条件查询 wrapper {#条件查询 wrapper}

条件构造器传送门

十分重要：Wrapper

我们写一些复杂的 sql 就可以使用它来替代！

测试类

@SpringBootTest
public class WrapperTest {

    <span class="token annotation punctuation">@Autowired</span>
    <span class="token keyword">private</span> <span class="token class-name">UserDao</span> userDao<span class="token punctuation">;</span>


    <span class="token comment">/**
     * 条件查询
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">wrapper1</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token comment">// 查询 name 不为空和 email 不为空并且年龄大于等于 12</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// 链式编程</span>
        wrapper<span class="token punctuation">.</span><span class="token function">isNotNull</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>
                <span class="token function">isNotNull</span><span class="token punctuation">(</span><span class="token string">"email"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>
                <span class="token function">ge</span><span class="token punctuation">(</span><span class="token string">"age"</span><span class="token punctuation">,</span> <span class="token number">20</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        userDao<span class="token punctuation">.</span><span class="token function">selectList</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>


    <span class="token comment">/**
     * 根据名称查询
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">wrapper2</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        wrapper<span class="token punctuation">.</span><span class="token function">eq</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">,</span> <span class="token string">"MoBai"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// selectOne(wrapper); 查询一个数据</span>
        <span class="token class-name">User</span> user <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectOne</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"user ="</span> <span class="token operator">+</span> user<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">/**
     * 查询区间
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">wrapper3</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// 查询年龄在 15-25 之间的数据</span>
        wrapper<span class="token punctuation">.</span><span class="token function">between</span><span class="token punctuation">(</span><span class="token string">"age"</span><span class="token punctuation">,</span> <span class="token number">15</span><span class="token punctuation">,</span> <span class="token number">25</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// selectOne(wrapper); 查询一个数据</span>
        <span class="token class-name">Integer</span> count <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectCount</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>count<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">/**
     * 模糊查询
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">test4</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        wrapper<span class="token punctuation">.</span>
                <span class="token comment">// 查询 name 不包含 e 的字段</span>
                <span class="token function">notLike</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">,</span> <span class="token string">"e"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>
                <span class="token comment">// 左和右 t%</span>
                <span class="token function">likeRight</span><span class="token punctuation">(</span><span class="token string">"email"</span><span class="token punctuation">,</span> <span class="token string">"t"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Map</span><span class="token punctuation">&lt;</span><span class="token class-name">String</span><span class="token punctuation">,</span> <span class="token class-name">Object</span><span class="token punctuation">&gt;</span><span class="token punctuation">&gt;</span></span> maps <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectMaps</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        maps<span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">/**
     * 模糊查询
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">test5</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// id 在子查询中查出来</span>
        wrapper<span class="token punctuation">.</span><span class="token function">inSql</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">,</span> <span class="token string">"select id from user where id &lt; 3"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">Object</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectObjs</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        list<span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>

    <span class="token comment">/**
     * 模糊查询
     */</span>
    <span class="token annotation punctuation">@Test</span>
    <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">test6</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> wrapper <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">QueryWrapper</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token comment">// 通过 ID 进行排序</span>
        wrapper<span class="token punctuation">.</span><span class="token function">orderByAsc</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
        <span class="token class-name">List</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">User</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> userDao<span class="token punctuation">.</span><span class="token function">selectList</span><span class="token punctuation">(</span>wrapper<span class="token punctuation">)</span><span class="token punctuation">;</span>
        list<span class="token punctuation">.</span><span class="token function">forEach</span><span class="token punctuation">(</span><span class="token class-name">System</span><span class="token punctuation">.</span>out<span class="token operator">::</span><span class="token function">println</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span>



}

其余的方法多练习, 多记笔记

代码自动生成器 {#代码自动生成器}

AutoGenerator 是 MyBatis-Plus 的代码生成器，通过 AutoGenerator 可以快速生成 Entity、Mapper、Mapper XML、Service、Controller 等各个模块的代码，极大的提升了开发效率。

官方文档

引入插件包

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <description>Demo project for Spring Boot</description>

    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>properties</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>java.version</span><span class="token punctuation">&gt;</span></span>1.8<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>java.version</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>properties</span><span class="token punctuation">&gt;</span></span>

    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependencies</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-web<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token comment">&lt;!-- 简化实体类 --&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.projectlombok<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>lombok<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>optional</span><span class="token punctuation">&gt;</span></span>true<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>optional</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token comment">&lt;!--MySQL 驱动 --&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>mysql<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>mysql-connector-java<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>5.1.43<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token comment">&lt;!--mybatis-plus 启动器 --&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>com.baomidou<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>mybatis-plus-boot-starter<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>3.0.5<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.apache.velocity<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>velocity-engine-core<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>2.0<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token comment">&lt;!--spring-boot-test--&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-test<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>scope</span><span class="token punctuation">&gt;</span></span>test<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>scope</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>exclusions</span><span class="token punctuation">&gt;</span></span>
                <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>exclusion</span><span class="token punctuation">&gt;</span></span>
                    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.junit.vintage<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
                    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>junit-vintage-engine<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
                <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>exclusion</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>exclusions</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependencies</span><span class="token punctuation">&gt;</span></span>



</project>

测试类

package com.mobai.mybatis_plus;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.po.TableFill;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;


import java.util.ArrayList;


/**

`
`
* 
  Software：IntelliJ IDEA 2020.1 x64





* 
  Author: MoBai·杰





* 
  Date: 2020/6/9 11:38





* 
  ClassName:MoBaiCode






* `
  `类描述： MybatisPlus 代码生成器
  /
  public class MoBaiCode {
  public static void main(String[] args) {
  // MybatisPlus 代码生成器必须要 new 一个 AutoGenerator 对象
  AutoGenerator mpg = new AutoGenerator();
  /*
  * 配置策略
  * 1. 全局配置
  */
  GlobalConfig gc = new GlobalConfig();
  // 获取当前资源路径
  String projectPath = System.getProperty("user.dir");
  // 生成的代码输出路径
  gc.setOutputDir(projectPath + "/src/main/java");
  // 生成作者信息
  gc.setAuthor("MoBai·杰");
  // 是否打开输出目录
  gc.setOpen(false);
  // 是否覆盖文件
  gc.setFileOverride(false);
  // 取消生成以后 I 前缀
  gc.setServiceName("%sService");
  // 指定生成的主键的 ID 类型
  gc.setIdType(IdType.ID_WORKER);
  // 只使用 java.util.date 代替
  gc.setDateType(DateType.ONLY_DATE);
  // 开启 swagger2 模式
  gc.setSwagger2(true);
  mpg.setGlobalConfig(gc);
  `
  `

       <span class="token comment">/**
        * 2. 配置数据源相关
        * DataSourceConfig: 数据库配置
        */</span>
       <span class="token class-name">DataSourceConfig</span> ds <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">DataSourceConfig</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       ds<span class="token punctuation">.</span><span class="token function">setDriverName</span><span class="token punctuation">(</span><span class="token string">"com.mysql.jdbc.Driver"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       ds<span class="token punctuation">.</span><span class="token function">setUrl</span><span class="token punctuation">(</span><span class="token string">"jdbc:mysql://localhost:3306/index?characterEncoding=utf-8"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       ds<span class="token punctuation">.</span><span class="token function">setUsername</span><span class="token punctuation">(</span><span class="token string">"root"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       ds<span class="token punctuation">.</span><span class="token function">setPassword</span><span class="token punctuation">(</span><span class="token string">"root"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 数据库类型</span>
       ds<span class="token punctuation">.</span><span class="token function">setDbType</span><span class="token punctuation">(</span><span class="token class-name">DbType</span><span class="token punctuation">.</span><span class="token constant">MYSQL</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       mpg<span class="token punctuation">.</span><span class="token function">setDataSource</span><span class="token punctuation">(</span>ds<span class="token punctuation">)</span><span class="token punctuation">;</span>


       <span class="token comment">/**
        * 3. 设置包的配置
        */</span>
       <span class="token class-name">PackageConfig</span> pc <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">PackageConfig</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 项目名称</span>
       pc<span class="token punctuation">.</span><span class="token function">setModuleName</span><span class="token punctuation">(</span><span class="token string">"cxdz"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 项目路径</span>
       pc<span class="token punctuation">.</span><span class="token function">setParent</span><span class="token punctuation">(</span><span class="token string">"com.mobai"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 实体类包名</span>
       pc<span class="token punctuation">.</span><span class="token function">setEntity</span><span class="token punctuation">(</span><span class="token string">"pojo"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// Dao 包名</span>
       pc<span class="token punctuation">.</span><span class="token function">setMapper</span><span class="token punctuation">(</span><span class="token string">"dao"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// service 包名</span>
       pc<span class="token punctuation">.</span><span class="token function">setService</span><span class="token punctuation">(</span><span class="token string">"service"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// service 实现类包名</span>
       pc<span class="token punctuation">.</span><span class="token function">setServiceImpl</span><span class="token punctuation">(</span><span class="token string">"service.impl"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// controller 包名</span>
       pc<span class="token punctuation">.</span><span class="token function">setController</span><span class="token punctuation">(</span><span class="token string">"controller"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       mpg<span class="token punctuation">.</span><span class="token function">setPackageInfo</span><span class="token punctuation">(</span>pc<span class="token punctuation">)</span><span class="token punctuation">;</span>

       <span class="token comment">/**
        * 4. 策略配置
        */</span>
       <span class="token class-name">StrategyConfig</span> sc <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">StrategyConfig</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 需要映射的表</span>
       sc<span class="token punctuation">.</span><span class="token function">setInclude</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 从数据库表到文件的命名策略 / 下划线转驼峰命名</span>
       sc<span class="token punctuation">.</span><span class="token function">setNaming</span><span class="token punctuation">(</span><span class="token class-name">NamingStrategy</span><span class="token punctuation">.</span>underline_to_camel<span class="token punctuation">)</span><span class="token punctuation">;</span>
       sc<span class="token punctuation">.</span><span class="token function">setColumnNaming</span><span class="token punctuation">(</span><span class="token class-name">NamingStrategy</span><span class="token punctuation">.</span>underline_to_camel<span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 是否为 lombok 模型 / 默认 false</span>
       sc<span class="token punctuation">.</span><span class="token function">setEntityLombokModel</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 设置逻辑删除字段</span>
       sc<span class="token punctuation">.</span><span class="token function">setLogicDeleteFieldName</span><span class="token punctuation">(</span><span class="token string">"deleted"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

       <span class="token comment">/**
        * 5. 设置自动填充
        */</span>
       <span class="token class-name">TableFill</span> gmtCreate <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">TableFill</span><span class="token punctuation">(</span><span class="token string">"gmt_create"</span><span class="token punctuation">,</span> <span class="token class-name">FieldFill</span><span class="token punctuation">.</span><span class="token constant">INSERT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token class-name">TableFill</span> gmtModified <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">TableFill</span><span class="token punctuation">(</span><span class="token string">"gmt_modified"</span><span class="token punctuation">,</span> <span class="token class-name">FieldFill</span><span class="token punctuation">.</span><span class="token constant">INSERT_UPDATE</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token class-name">ArrayList</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token class-name">TableFill</span><span class="token punctuation">&gt;</span></span> list <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token generics"><span class="token punctuation">&lt;</span><span class="token punctuation">&gt;</span></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       list<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>gmtCreate<span class="token punctuation">)</span><span class="token punctuation">;</span>
       list<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span>gmtModified<span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 表填充字段</span>
       sc<span class="token punctuation">.</span><span class="token function">setTableFillList</span><span class="token punctuation">(</span>list<span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 设置乐观锁字段</span>
       sc<span class="token punctuation">.</span><span class="token function">setVersionFieldName</span><span class="token punctuation">(</span><span class="token string">"version"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 生成 @RestController 控制器</span>
       sc<span class="token punctuation">.</span><span class="token function">setRestControllerStyle</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 驼峰转连字符</span>
       sc<span class="token punctuation">.</span><span class="token function">setControllerMappingHyphenStyle</span><span class="token punctuation">(</span><span class="token boolean">true</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
       mpg<span class="token punctuation">.</span><span class="token function">setStrategy</span><span class="token punctuation">(</span>sc<span class="token punctuation">)</span><span class="token punctuation">;</span>
       <span class="token comment">// 执行</span>
       mpg<span class="token punctuation">.</span><span class="token function">execute</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>


  `
  `

  }`
  `}