aapple/dynamic-datasource-spring-boot-starter

dynamic datasource for springboot2 多数据源 动态数据源

dynamic-datasource-spring-boot-starter

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Introduction

dynamic-datasource-spring-boot-starter based on springBoot2.0.

It can be used for Separation of reading and writing.

The master database to INSERT UPDATE DELETE .

The slave database to SELECT .

If you project is complex,I will propose you use sharding-jdbc .

Demo

dynamic-datasource-example a simple dynamic project that u can direct run。

How to use

1. Import dynamic-datasource-spring-boot-starter。

<dependency>
  <groupId>com.baomidou</groupId>
  <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
  <version>1.0.0</version>
</dependency>

2. Config your master-slave info in application.yml。

spring.datasource.dynamic.master （config the unique master database）

spring.datasource.dynamic.slaves （config every slave database）

spring:
  datasource:
    dynamic:
      master:
        username: root
        password: 123456
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://47.100.20.186:3307/dynamic?characterEncoding=utf8&useSSL=false
      slaves:
        one:
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver
          url: jdbc:mysql://47.100.20.186:3308/dynamic?characterEncoding=utf8&useSSL=false
        two:
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver
          url: jdbc:mysql://47.100.20.186:3309/dynamic?characterEncoding=utf8&useSSL=false

3. Use annotation @DS to switch database.

@DS can be annotation on serviceImpl method or mybatis mapper method.

annotation	result
without @DS	master
@DS("one")	If exist a database named 'one' then switch to one,otherwise to master
@DS	depensOn DynamicDataSourceStrategy to determine a slave database,the default strategy is LoadBalance.

@Service
public class UserServiceImpl implements UserService {

  @Autowired
  private JdbcTemplate jdbcTemplate;

  @DS("one")
  public List<Map<String, Object>> selectAll() {
    return  jdbcTemplate.queryForList("select * from user");
  }
  
  @Override
  @DS
  public List<Map<String, Object>> selectByCondition() {
    return  jdbcTemplate.queryForList("select * from user where age >10");
  }

}

In mybatis environment it can also annotation on mapper method.

public interface UserMapper {

  @Insert("INSERT INTO user (name,age) values (#{name},#{age})")
  boolean addUser(@Param("name") String name, @Param("age") Integer age);

  @Update("UPDATE user set name=#{name}, age=#{age} where id =#{id}")
  boolean updateUser(@Param("id") Integer id, @Param("name") String name, @Param("age") Integer age);

  @Delete("DELETE from user where id =#{id}")
  boolean deleteUser(@Param("id") Integer id);

  @Select("SELECT * FROM user")
  @DS
  List<User> selectAll();

}

Custom config

1. Config DynamicDataSourceProvider .

The default DynamicDataSourceProvider is YmlDynamicDataSourceProvider，It read database info from application.yaml or application.properties .

public interface DynamicDataSourceProvider {

  /**
   * load master
   *
   * @return masterDataSource
   */
  DataSource loadMasterDataSource();

  /**
   * load slaves
   *
   * @return slaveDataSource
   */
  Map<String, DataSource> loadSlaveDataSource();

}

2. Config DynamicDataSourceStrategy.

The default DynamicDataSourceStrategy is LoadBalanceDynamicDataSourceStrategy .

The starter alse provide RandomDynamicDataSourceStrategy.

public interface DynamicDataSourceStrategy {

  /**
   * determine a slaveId
   *
   * @param slaveDataSourceLookupKeys slaveKeys
   * @return slaveId
   */
  String determineSlaveDataSource(String[] slaveDataSourceLookupKeys);

}

Demo to use RandomDynamicDataSourceStrategy instead of LoadBalanceDynamicDataSourceStrategy .

@Configuration
public class DynamicConfiguration {
 
  @Bean
  public DynamicDataSourceStrategy dynamicDataSourceStrategy() {
    return new RandomDynamicDataSourceStrategy();
  }

}