這次要完成的是從一個數據庫中讀取資料，然後再把資料插入到另一個數據庫中。在同一套專案程式碼中要完成這個操作，就不可避免的涉及到了多資料來源。本文即介紹在mybatis中完成多資料來源的切換相關內容

指定資料來源一

@Configuration
// 掃描 Mapper 介面並容器管理
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE,sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {

  // 精確到 master 目錄，以便跟其他資料來源隔離
  static final String PACKAGE = "com.datareach.kafka.dao.master";
  static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";
	//application.yml中的值可以通過@Value註解進行讀取
  @Value("${master.datasource.url}")
  private String url;
  @Value("${master.datasource.username}")
  private String user;
  @Value("${master.datasource.password}")
  private String password;
  @Value("${master.datasource.driver-class-name}")
  private String driverClass;

  @Bean(name = "masterDataSource")
  @Primary
  public DataSource masterDataSource() {
    DruidDataSource dataSource = new DruidDataSource();
    dataSource.setDriverClassName(driverClass);
    dataSource.setUrl(url);
    dataSource.setUsername(user);
    dataSource.setPassword(password);
    return dataSource;
  }

  @Bean(name = "masterTransactionManager")
  @Primary
  public DataSourceTransactionManager masterTransactionManager() {
    return new DataSourceTransactionManager(masterDataSource());
  }

  @Bean(name = "masterSqlSessionFactory")
  @Primary
  public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
      throws Exception {
    final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
    sessionFactory.setDataSource(masterDataSource);
    sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
        .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
    return sessionFactory.getObject();
  }
}

資料來源一的相關配置

# master 資料來源配置
master:
 datasource:
  url: jdbc:postgresql://localhost:5432/postgres?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false&serverTimezone=GMT%2B8
  driver-class-name: org.postgresql.Driver
  username: product
  password: 
  initial-size: 1
  min-idle: 1
  max-active: 20
  test-on-borrow: true
  max-wait: 60000
  time-between-eviction-runs-millis: 60000
  min-evictable-idle-time-millis: 300000
  validation-query: SELECT 1 FROM DUAL
  test-While-Idle: true
  test-on-return: false
  pool-prepared-statements: false
  max-pool-prepared-statement-per-connection-size: 20
  filters: stat,wall,log4j,config

指定資料來源二

@Configuration
// 掃描 Mapper 介面並容器管理
@MapperScan(basePackages = SecondDataSourceConfig.PACKAGE,sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {
  // 精確到 cluster 目錄，以便跟其他資料來源隔離
  static final String PACKAGE = "com.datareach.kafka.dao.secondary";
  static final String MAPPER_LOCATION = "classpath:mapper/secondary/*.xml";
  @Value("${second.datasource.url}")
  private String url;
  @Value("${second.datasource.username}")
  private String user;
  @Value("${second.datasource.password}")
  private String password;
  @Value("${second.datasource.driver-class-name}")
  private String driverClass;

  @Bean(name = "secondDataSource")
  public DataSource clusterDataSource() {
    DruidDataSource dataSource = new DruidDataSource();
    dataSource.setDriverClassName(driverClass);
    dataSource.setUrl(url);
    dataSource.setUsername(user);
    dataSource.setPassword(password);
    return dataSource;
  }
  @Bean(name = "secondTransactionManager")
  public DataSourceTransactionManager clusterTransactionManager() {
    return new DataSourceTransactionManager(clusterDataSource());
  }
  @Bean(name = "secondSqlSessionFactory")
  public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("secondDataSource") DataSource clusterDataSource)
      throws Exception {
    final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
    sessionFactory.setDataSource(clusterDataSource);
    sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
        .getResources(SecondDataSourceConfig.MAPPER_LOCATION));
    return sessionFactory.getObject();
  }
}

資料來源二的相關配置

second:
 datasource:
  url: jdbc:mysql://localhost:40000/PG_Data?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false&serverTimezone=GMT%2B8
  username: root
  password: 
  driver-class-name: com.mysql.jdbc.Driver
  max-idle: 10
  max-wait: 10000
  min-idle: 5
  initial-size: 5

其實就是例項化了兩個SqlSessionFactory——masterSqlSessionFactory和secondSqlSessionFactory，然後通過註解@MapperScan指定掃描指定的mapper介面時用指定的SqlSessionFactory進行連線構建，從而實現了多資料來源。

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。