springboot学习入门简易版九---springboot2.0整合多数据源mybatis mysql8+（22)

一个项目中配置多个数据源(链接不同库jdbc)，无限大，具体多少根据内存大小

项目中多数据源如何划分：分包名(业务）或注解方式。分包名方式类似多个不同的jar，同业务需求放一个包中。

分包方式配置多数据源

项目目录结构

2.14.1 pom文件

<parent>

     <groupId>org.springframework.boot</groupId>

     <artifactId>spring-boot-starter-parent</artifactId>

     <version>2.0.9.RELEASE</version>

 </parent>

 <properties>

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

    <java.version>1.8</java.version>

</properties>

 <dependencies>

     <dependency>

         <groupId>org.springframework.boot</groupId>

         <artifactId>spring-boot-starter-web</artifactId>

     </dependency>

     <!-- mybatis-spring-boot-starter -->

        <dependency>

            <groupId>org.mybatis.spring.boot</groupId>

            <artifactId>mybatis-spring-boot-starter</artifactId>

            <version>2.0.1</version>

        </dependency>

        <!-- mysql 驱动 -->

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>8.0.11</version>

        </dependency>

        <!-- 提示建议引入 -->

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-configuration-processor</artifactId>

            <optional>true</optional>

        </dependency>

 </dependencies>

2.14.2 创建test1包名下类

public class Employee implements Serializable{

    private static final long serialVersionUID = 1L;

    private Integer id;

    private String lastName;

public interface EmployeeDao {

//    @Insert("insert into myemployeee(last_name) values (#{lastName})")

    int insert(Employee emp);

}

EmployeeMapping.xml文件

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE mapper

  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

  <mapper namespace="com.springboot2.test1.dao.EmployeeDao">

  <insert id="insert" parameterType="com.springboot2.test1.bean.Employee">

    insert into myemployeee(last_name) values (#{lastName,jdbcType=VARCHAR})

  </insert>

</mapper>

service类

@Service

public class EmployeeService {

    @Autowired

    EmployeeDao employeeDao;

    public Integer insert(Employee emp) {

        return employeeDao.insert(emp);

    }

}

2.14.3 创建test2包名下类

public class User implements Serializable{

    private static final long serialVersionUID = 1L;

    private Integer id;

    private String name;

    private Integer age;

public interface UserDao {

//    @Insert("insert into myuser(name,age) values (#{name},#{age})")

    int insert(User user);

}

UserMapping.xml文件

<!DOCTYPE mapper

  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

  <mapper namespace="com.springboot2.test2.dao.UserDao">

  <insert id="insert" parameterType="com.springboot2.test2.bean.User">

    insert into myuser(name,age) values (#{name,jdbcType=VARCHAR},#{age,jdbcType=INTEGER})

  </insert>

</mapper>

@Service

public class UserService {

    @Autowired

    UserDao userDao;

    public Integer insert(User user2) {

        return userDao.insert(user2);

    }

}

2.14.4 重点：多数据源配置

2.14.4.1首先application.yml文件

#多数据源配置

spring:

  datasource:

    test1: #数据源1(自定义)

      driver-class-name: com.mysql.cj.jdbc.Driver

      jdbc-url: jdbc:mysql://localhost:3306/mytest?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8&allowMultiQueries=true

      username: root

      password: (***)

    test2: #数据源2(自定义)

      driver-class-name: com.mysql.cj.jdbc.Driver

      jdbc-url: jdbc:mysql://localhost:3306/mytest2?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8&allowMultiQueries=true

      username: root

      password: (***)

注意：虽然为高版本，但多数据源配置时，必须为spring.datasource.test.jdbc-url而不是spring.datasource.test.url

2.14.4.2多数据源配置类

/**

 * 数据源配置

 * @author admin

 *

 */

@Configuration

@MapperScan(basePackages= "com.springboot2.test1.dao",sqlSessionFactoryRef="test1SqlSessionFactory") //注意：com.springboot2.test1.dao是dao类的包名！！

public class DatasourceConfig1 {

    /**

     * 配置test1数据库

     * @return

     */

    @Bean(name="test1DataSource")

    @ConfigurationProperties(prefix="spring.datasource.test1")

    @Primary

    public DataSource test1DataSource() {

        return DataSourceBuilder.create().build();

    }

    /**

     * 创建sqlsessinfactory会话工厂

     * @param dataSource

     * @return

     * @throws Exception

     */

    @Bean(name="test1SqlSessionFactory")

    @Primary

    public SqlSessionFactory test1SqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource) throws Exception {

        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();

        sqlSessionFactoryBean.setDataSource(dataSource);

        //加载mapping文件

        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()

            .getResources("classpath:com/springboot2/test1/mapping/*.xml"));

        return sqlSessionFactoryBean.getObject();

    }

    /**

     * 事务管理

     */

    @Bean(name="test1TransactionManager")

    @Primary

    public DataSourceTransactionManager test1TransactionManager(@Qualifier("test1DataSource") DataSource dataSource) {

        return new DataSourceTransactionManager(dataSource);

    }

    /**

     * 创建SqlSessionTemplate

     * @param sqlSessionFactory

     * @return

     */

    @Bean(name="test1SqlSessionTemplate")

    @Primary

    public SqlSessionTemplate test1SqlSessionTemplate(@Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory){

        return new SqlSessionTemplate(sqlSessionFactory);

    }

}

/**

 * 数据源配置

 * @author admin

 *

 */

@Configuration

@MapperScan(basePackages= {"com.springboot2.test2.dao"},sqlSessionFactoryRef="test2SqlSessionFactory")

public class DatasourceConfig2 {

    /**

     * 配置test2数据库

     * @return

     */

    @Bean(name="test2DataSource")

    @ConfigurationProperties(prefix="spring.datasource.test2")

    public DataSource test2DataSource() {

        return DataSourceBuilder.create().build();

    }

    /**

     * 创建sqlsessinfactory会话工厂

     * @param dataSource

     * @return

     * @throws Exception

     */

    @Bean(name="test2SqlSessionFactory")

    public SqlSessionFactory test2SqlSessionFactory(@Qualifier("test2DataSource") DataSource dataSource) throws Exception {

        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();

        sqlSessionFactoryBean.setDataSource(dataSource);

        //加载mapping文件

        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()

            .getResources("classpath:com/springboot2/test2/mapping/*.xml"));

        return sqlSessionFactoryBean.getObject();

    }

    /**

     * 事务管理

     */

    @Bean(name="test2TransactionManager")

    public DataSourceTransactionManager test2TransactionManager(@Qualifier("test2DataSource") DataSource dataSource) {

        return new DataSourceTransactionManager(dataSource);

    }

    /**

     * 创建SqlSessionTemplate

     * @param sqlSessionFactory

     * @return

     */

    @Bean(name="test2SqlSessionTemplate")

    public SqlSessionTemplate test2SqlSessionTemplate(@Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory){

        return new SqlSessionTemplate(sqlSessionFactory);

    }

}

注意：

1）分包方式下@Primary可以不写！

2）mapperscan扫描为dao类对应的包名而不是dao类，否则会导致无法注入，报错缺少component注解。

2.14.5 controller类

@RestController

public class MultiDataSourceController {

    @Autowired

    EmployeeService employeeService1;

    @Autowired

    UserService userService;

    @RequestMapping("/insertEmployee")

    public String insert(String lastName){

        Employee emp=new Employee();

        emp.setLastName(lastName);

        int i=employeeService1.insert(emp);

        return i+"";

    }

    //接收json格式请求

    @RequestMapping("/insertUser")

    public String insert(@RequestBody User user){

        User user2=new User();

        user2.setAge(user.getAge());

        user2.setName(user.getName());

        int i=userService.insert(user2);

        return i+"";

    }

    //接收普通格式多参数请求

    @RequestMapping("/insertUser2")

    public String insertUser2(@RequestParam("name") String name,@RequestParam("age") Integer age){

        User user2=new User();

        user2.setAge(age);

        user2.setName(name);

        int i=userService.insert(user2);

        return i+"";

    }

2.14.7 启动类

@SpringBootApplication

//@MapperScan("com.springboot2.dao")//多数据源下在数据源配置中配置DatasourceConfig1和DatasourceConfig2

public class StartApplication {

    public static void main(String[] args) {

        SpringApplication.run(StartApplication.class, args);

    }

}

2.14.8 测试

1 Get请求：http://localhost:8080/insertEmployee?lastName=test2222

执行成功返回1

2 Post请求（且content-type为application/json类型）

http://localhost:8080/insertUser

请求参数：

{

"name":"test3",

"age":11

}

返回成功1

3 get请求（content-type类型随意）

http://localhost:8080/insertUser2?name=ttdd&age=22

返回成功1

2.15SpringBoot多数据源事务（24）

@Service

public class EmployeeService {

    @Autowired

    EmployeeDao employeeDao;

    /**

     * 添加事务管理

     * @param emp

     * @return

     * @throws Exception

     */

    @Transactional(transactionManager="test1TransactionManager",rollbackFor=Exception.class)

    public Integer insert(Employee emp) throws Exception{

        /**

         * 抛出异常事务无效：默认检测unchecked异常才回滚，checked异常也回滚需要设置rollbackFor=Exception.class

         * https://www.cnblogs.com/syp172654682/p/9811341.html

         */

        int i=this.other(emp);

        return i;

    }

    @Transactional(transactionManager="test1TransactionManager")

    public Integer other(Employee emp) throws Exception{

        int i=employeeDao.insert(emp);

        try {

            i=i/0;

        }catch(Exception e) {

            Logger.logMsg(Logger.INFO, "异常");

            throw new Exception();

        }

        return i;

    }

}

启动类

@SpringBootApplication

@EnableTransactionManagement

//@MapperScan("com.springboot2.dao")//多数据源下在数据源配置中配置DatasourceConfig1和DatasourceConfig2

public class StartApplication {

    public static void main(String[] args) {

        SpringApplication.run(StartApplication.class, args);

    }

}

问题：

1）抛出Exception异常事务无效，原因及解决方法见上面代码

2）其他事务失效问题见：https://www.cnblogs.com/cslj2013/p/10924755.html

github: https://github.com/cslj2013/springboot2.0_multi_datasources.git

巴特西