Spring Boot + MyBatis + Druid环境下配置多数据源_mybatis. hana

项目中采用Spring Boot + MyBatis + Druid的架构，在原数据源的基础上需要添加一个新的数据源。

调试期间，发现添加了SqlSessionFactoryBean后，原数据源有一部分字段无法取值，后发现是application.yml中的配置失效，所以需要在SqlSessionFactoryBean中添加所需配置。

1. 在application.yml下配置两套数据源信息

默认数据源：

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.10:3306/database1?useUnicode=true&characterEncoding=utf8
    username: root
    password: ****
    initialSize: 1
    minIdle: 3
    maxActive: 20
    # 配置获取连接等待超时的时间
    maxWait: 60000
    # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    minEvictableIdleTimeMillis: 30000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false

新增数据源

hana:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.6.12:3306/hana?useUnicode=true&characterEncoding=utf8
 
    username: root
    password: 1234
    initialSize: 1
    minIdle: 3
    maxActive: 20
    # 配置获取连接等待超时的时间
    maxWait: 60000
    # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一个连接在池中最小生存的时间，单位是毫秒
    minEvictableIdleTimeMillis: 30000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false

2. 针对两个数据源分别写配置类DruidDBConfig.java 

要点：

a. basePackages 指定该数据源对应的MyBatis的Mapper类所在的包，表示指定包名下的数据库操作使用该数据源；

@MapperScan(basePackages = {"com.simba.*.dao"}, sqlSessionFactoryRef = "masterSqlSessionFactory ")

sqlSessionFactoryRef 指向了下面定义的bean

b. 定义一个masterSqlSessionFactory bean

如下代码指定了MyBatis的XML Mapping文件的路径和MapUnderscoreToCamelCase属性

        Resource[] resource = new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/**/*Mapper.xml");
        sqlSessionFactoryBean.setMapperLocations(resource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);

它替代了原来application.yml中的配置，需注意的是，加了sqlSessionFactory bean 后，如下配置将不再生效，因此相关配置需在sqlSessionFactory 中完成。

#[弃用]因为多数据源需要，MyBatis配置弃用，具体配置见DruidDBConfig
#mybatis:
#  configuration:
#    map-underscore-to-camel-case: true
#  mapper-locations: mybatis/**/*Mapper.xml
#  typeAliasesPackage: com.simba.**.domain

默认数据源的配置Bean

@Configuration
@MapperScan(basePackages = {"com.simba.*.dao"}, sqlSessionFactoryRef = "masterSqlSessionFactory")//指定该数据源相应的MyBatis的Mapper类所在的包
public class DruidDBConfig {
    private Logger logger = LoggerFactory.getLogger(DruidDBConfig.class);
    @Value("${spring.datasource.url}")
    private String dbUrl;
 
    @Value("${spring.datasource.username}")
    private String username;
 
    @Value("${spring.datasource.password}")
    private String password;
 
    @Value("${spring.datasource.driverClassName}")
    private String driverClassName;
 
    @Value("${spring.datasource.initialSize}")
    private int initialSize;
 
    @Value("${spring.datasource.minIdle}")
    private int minIdle;
 
    @Value("${spring.datasource.maxActive}")
    private int maxActive;
 
    @Value("${spring.datasource.maxWait}")
    private int maxWait;
 
    @Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
    private int timeBetweenEvictionRunsMillis;
 
    @Value("${spring.datasource.minEvictableIdleTimeMillis}")
    private int minEvictableIdleTimeMillis;
 
    @Value("${spring.datasource.validationQuery}")
    private String validationQuery;
 
    @Value("${spring.datasource.testWhileIdle}")
    private boolean testWhileIdle;
 
    @Value("${spring.datasource.testOnBorrow}")
    private boolean testOnBorrow;
 
    @Value("${spring.datasource.testOnReturn}")
    private boolean testOnReturn;
 
    @Bean(initMethod = "init", destroyMethod = "close")   //声明其为Bean实例
    @Primary  //在同样的DataSource中，首先使用被标注的DataSource
    public DataSource dataSource() {
        DruidDataSource datasource = new DruidDataSource();
 
        datasource.setUrl(this.dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);
 
        //configuration
        datasource.setInitialSize(initialSize);
        datasource.setMinIdle(minIdle);
        datasource.setMaxActive(maxActive);
        datasource.setMaxWait(maxWait);
        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setValidationQuery(validationQuery);
        datasource.setTestWhileIdle(testWhileIdle);
        datasource.setTestOnBorrow(testOnBorrow);
        datasource.setTestOnReturn(testOnReturn);
        return datasource;
    }
 
 
    //创建Session
    @Bean(name="masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("dataSource") DataSource dataSource) throws Exception{
        final SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        Resource[] resource = new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/**/*Mapper.xml");//MyBatis XML文件所在路径
        sqlSessionFactoryBean.setMapperLocations(resource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }
}

新增数据源的配置bean

@Configuration
@MapperScan(basePackages = "com.hana.dao", sqlSessionFactoryRef = "hanaSqlSessionFactory")
public class HanaDruidDBConfig {
    private Logger logger = LoggerFactory.getLogger(HanaDruidDBConfig.class);
    @Value("${hana.datasource.url}")
    private String dbUrl;
 
    @Value("${hana.datasource.username}")
    private String username;
 
    @Value("${hana.datasource.password}")
    private String password;
 
    @Value("${hana.datasource.driverClassName}")
    private String driverClassName;
 
    @Value("${hana.datasource.initialSize}")
    private int initialSize;
 
    @Value("${hana.datasource.minIdle}")
    private int minIdle;
 
    @Value("${hana.datasource.maxActive}")
    private int maxActive;
 
    @Value("${hana.datasource.maxWait}")
    private int maxWait;
 
    @Value("${hana.datasource.timeBetweenEvictionRunsMillis}")
    private int timeBetweenEvictionRunsMillis;
 
    @Value("${hana.datasource.minEvictableIdleTimeMillis}")
    private int minEvictableIdleTimeMillis;
 
    @Value("${hana.datasource.validationQuery}")
    private String validationQuery;
 
    @Value("${hana.datasource.testWhileIdle}")
    private boolean testWhileIdle;
 
    @Value("${hana.datasource.testOnBorrow}")
    private boolean testOnBorrow;
 
    @Value("${hana.datasource.testOnReturn}")
    private boolean testOnReturn;
 
    @Bean(initMethod = "init", destroyMethod = "close")   //声明其为Bean实例
    public DataSource hanaDataSource() {
        DruidDataSource datasource = new DruidDataSource();
 
        datasource.setUrl(this.dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);
 
        //configuration
        datasource.setInitialSize(initialSize);
        datasource.setMinIdle(minIdle);
        datasource.setMaxActive(maxActive);
        datasource.setMaxWait(maxWait);
        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setValidationQuery(validationQuery);
        datasource.setTestWhileIdle(testWhileIdle);
        datasource.setTestOnBorrow(testOnBorrow);
        datasource.setTestOnReturn(testOnReturn);
        return datasource;
    }
 
 
    //创建Session
    @Bean(name="hanaSqlSessionFactory")
    public SqlSessionFactory hanaSqlSessionFactory(@Qualifier("hanaDataSource") DataSource hanaDataSource) throws Exception{
        final SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(hanaDataSource);
        /*Resource[] resource = new PathMatchingResourcePatternResolver().getResources(ClusterConfig.MAPPER_LOCATION);
        sqlSessionFactoryBean.setMapperLocations(resource);*/
        return sqlSessionFactoryBean.getObject();
    }
}

这样就完成了配置，根据MapperScan中所指定的包名，自动选择相应数据源进行数据操作。