SpringBoot整合Mybatis多数据源

一、SpringBoot整合Mybatis

1.导入相关依赖

<!--mysql驱动,druid连接池,jdbc,web起步依赖-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.24</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

2.数据库配置

CREATE TABLE `t_book` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(128) DEFAULT NULL,
  `author` varchar(64) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8

INSERT INTO `jdbc`.`t_book` (`id`, `name`, `author`) VALUES ('1', '三国演义', '罗贯中');
INSERT INTO `jdbc`.`t_book` (`id`, `name`, `author`) VALUES ('2', '水浒传', '施耐庵');

3.创建pojo实体类和Result实体类

//与数据库表对应的实体类
public class Book implements Serializable {
    private Integer id;
    private String name;
    private String author;
    //getter... setter...
}

//返回前端结果Result实体类
public class Result<T> implements Serializable {

    private boolean flag;           //是否成功
    private Integer code;           //返回码
    private String message;         //返回消息
    private T data;                 //返回对象
    //constuctor... getter... setter...
}

4.application.yml配置

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/jdbc
    username: root
    password: root

5.Dao层代码

@Mapper
public interface BookMapper {
    @Insert("insert into t_book(name,author) values (#{name},#{author})")
    int addBook(Book book);

    @Delete("delete from t_book where id = #{id}")
    int deleteBookById(Integer id);

    @Update("update t_book set name=#{name},author=#{author} where id = #{id}")
    int update(Book book);

    @Select("select * from t_book where id = #{id}")
    Book getBookById(Integer id);

    @Select("select * from t_book")
    List<Book> getAllBooks();
}

6.Service层代码

@Service
public class BookService {

    @Autowired
    private BookMapper bookMapper;

    //添加图书
    public int addBook(Book book){
        return bookMapper.addBook(book);
    }

    //更新图书
    public int updateBook(Book book){
        return bookMapper.update(book);
    }

    //根据Id删除图书
    public int deleteBookById(Integer id){
        return bookMapper.deleteBookById(id);
    }

    //根据Id查找图书
    public Book getBookById(Integer id){
        return bookMapper.getBookById(id);
    }

    //查找所有图书
    public List<Book> getAllBooks(){
        return bookMapper.getAllBooks();
    }

}

7.Controller层代码

@RestController
@RequestMapping("/book")
@CrossOrigin
public class BookController {

    @Autowired
    private BookService bookService;

    //查找所有书籍
    @GetMapping
    public Result<List<Book>> getAllBooks(){
        List<Book> bookList = bookService.getAllBooks();
        return new Result<>(true, 200, "查询成功",bookList);
    }

    //根据id查找书籍
    @GetMapping("/{id}")
    public Result<Book> getBookById(@PathVariable("id") Integer id){
        Book book = bookService.getBookById(id);
        return new Result<>(true, 200,"查询成功",book);
    }

    //根据id删除书籍
    @DeleteMapping("/{id}")
    public Result<Integer> deleteBookById(@PathVariable("id") Integer id){
        int i = bookService.deleteBookById(id);
        return new Result<>(true,200,"删除成功",i);
    }

    //更新书籍
    @PutMapping("/{id}")
    public Result<Integer> updateBook(@RequestBody Book book, @PathVariable("id") Integer id){
        book.setId(id);
        int i = bookService.updateBook(book);
        return new Result<>(true, 200, "更新成功",i);
    }

    //增加书籍
    @PostMapping
    public Result<Integer> addBook(@RequestBody Book book){
        int i = bookService.addBook(book);
        return new Result<>(true, 200, "添加成功",i);
    }

}

二、Mybatis配置多数据源

1.导入pom依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.24</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

2.application.yml配置多数据源连接信息

spring:
  datasource:
    one:
      type: com.alibaba.druid.pool.DruidDataSource
      url: jdbc:mysql://localhost:3306/jdbc
      username: root
      password: root
    two:
      type: com.alibaba.druid.pool.DruidDataSource
      url: jdbc:mysql://localhost:3306/jdbc2
      username: root
      password: root

3.配置多个数据源实例Bean

@Configuration
public class DataSourceConfig {

    @ConfigurationProperties(prefix = "spring.datasource.one")
    @Bean(name = "dsOne")
    public DataSource dsOne(){
        return DruidDataSourceBuilder.create().build();
    }

    @ConfigurationProperties(prefix = "spring.datasource.two")
    @Bean(name = "dsTwo")
    public DataSource dsTwo(){
        return DruidDataSourceBuilder.create().build();
    }

}

4.配置多个SqlSessionFactory和SqlSessionTemplate

@Configuration
@MapperScan(value = "cn.codeduck.mybatis.mapper1", sqlSessionFactoryRef = "sqlSessionFactory1")
public class MybatisConfigOne {
    @Autowired
    @Qualifier("dsOne")
    DataSource dsOne;

    @Bean
    SqlSessionFactory sqlSessionFactory1() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dsOne);
        return factoryBean.getObject();
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplate1() throws Exception{
        return new SqlSessionTemplate(sqlSessionFactory1());
    }

}

@Configuration
@MapperScan(value = "cn.codeduck.mybatis.mapper2", sqlSessionFactoryRef = "sqlSessionFactory2")
public class MybatisConfigTwo {

    @Autowired
    @Qualifier("dsTwo")
    DataSource dsTwo;

    @Bean
    SqlSessionFactory sqlSessionFactory2() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dsTwo);
        return factoryBean.getObject();
    }

    @Bean
    SqlSessionTemplate sqlSessionTemplate2() throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory2());
    }

}

5.简单测试

@RestController
public class MybatisDsController {

    @Autowired
    private BookMapper1 bookMapper1;

    @Autowired
    private BookMapper2 bookMapper2;

    @GetMapping("/test1")
    public void test1(){
        List<Book> list1 = bookMapper1.getAllBooks();
        List<Book> list2 = bookMapper2.getAllBooks();
        System.out.println(list1);
        System.out.println(list2);
    }

}

三、Mybatis整合通用Mapper

1.导入pom依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.24</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>tk.mybatis</groupId>
    <artifactId>mapper-spring-boot-starter</artifactId>
    <version>2.1.5</version>
</dependency>

2.application.yml配置

#通用mapper配置
mapper:
  #公用接口类路径
  mappers: cn.codeduck.mybatis.mapper3.IBaseMapper
  identity: MYSQL
#实体类所在包名
mybatis:
  type-aliases-package: cn.codeduck.mybatis.pojo

3.创建实体类

@Repository
@Table(name = "t_person")   //mybatis通用接口mapper依赖JPA实体类采用JPA
public class Person implements Serializable {

    @Id     //返回自增长主键
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "name")  //数据库属性名称
    private String name;

    @Column(name = "age")
    private Integer age;

    //getter...  setter...
}

4.创建公用mapper接口

import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;

//创建公用Mapper接口
public interface BaseMapper<T> extends Mapper<T>, MySqlMapper<T> {
}

5.创建普通Dao接口(继承公用Mapper接口)

public interface PersonMapper extends BaseMapper<Person> {
}

6.启动类包扫描(扫描普通Dao接口)

@SpringBootApplication
@MapperScan(value = "cn.codeduck.mybatis.dao",sqlSessionFactoryRef = "sqlSessionFactory1")
//注意MapperScan要导tk的包，不然会报NoSuchMethodException，由于配置了多个数据源，所以要指定用哪一个sqlSessionFactory
public class MybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisApplication.class, args);
    }

}

7.简单测试

@RestController
public class TKController {

    @Autowired
    private PersonMapper personMapper;

    @GetMapping("/person/{id}")
    public String findPersonById(@PathVariable("id") Integer id){
        Person person = personMapper.selectByPrimaryKey(id);
        return person.toString();
    }

}