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Spring Boot多数据源整合 #64

Open Zakariyya opened 4 years ago

Zakariyya commented 4 years ago

date: 2018-07-19 17:48:20

如何用Spring Boot 整合 MyBatis 连接多种数据源 & Spring Data Jpa 如何连接多种数据源

引入依赖项公用

dependencies {
    compile('org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.1')
    compile('org.springframework.boot:spring-boot-starter-web')
    runtime('mysql:mysql-connector-java')
    runtime('com.microsoft.sqlserver:mssql-jdbc')
    testCompile('org.springframework.boot:spring-boot-starter-test')
}

配置数据源公用

新建数据源配置类

@Configuration
public class DataSourceProperties {

    @Bean("mysqlDataSource")
    @ConfigurationProperties(prefix = "datasource.mysql")

    @Primary
    public DataSource mysqlDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean("mssqlDataSource")
    @ConfigurationProperties(prefix = "datasource.mssql")
    public DataSource mssqlDataSource(){
        return DataSourceBuilder.create().build();
    }

}

application.properties配置数据源

datasource.mysql.url=jdbc:mysql://xx?serverTimezone=Asia/Shanghai&characterEncoding=utf8
datasource.mysql.username=xx
datasource.mysql.password=xx
datasource.mysql.driver-class-name=com.mysql.jdbc.Driver
datasource.mssql.url=jdbc:sqlserver://xx;databasename=xx
datasource.mssql.username=xx
datasource.mssql.password=xx
datasource.mssql.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver

MyBatis配置

mssql配置

@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = "指定mssql repository包名", sqlSessionFactoryRef = "mssqlSessionFactory")
public class MssqlConfig {
    @Autowired
    @Qualifier("mssqlDataSource")
    private DataSource mssqlDataSource;

    @Bean(name = "mssqlTransactionManager")
    public DataSourceTransactionManager dataSourceTransactionManager() {
        return new DataSourceTransactionManager(mssqlDataSource);
    }

    @Bean(name = "mssqlSessionFactory")
    public SqlSessionFactory clusterSqlSessionFactory() throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(mssqlDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:config/mybatis/mapper/*.xml"));
        return sessionFactory.getObject();
    }

}

mysql配置

@Configuration
@EnableTransactionManagement
@MapperScan(basePackages = "指定mysql repository包名", sqlSessionFactoryRef = "mysqlSessionFactory")
public class MySqlConfig {
    @Autowired
    @Qualifier("mysqlDataSource")
    private DataSource mysqlDataSource;

    @Bean(name = "mysqlTransactionManager")
    @Primary
    public DataSourceTransactionManager dataSourceTransactionManager() {
        return new DataSourceTransactionManager(mysqlDataSource);
    }

    @Bean(name = "mysqlSessionFactory")
    @Primary
    public SqlSessionFactory clusterSqlSessionFactory() throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(mysqlDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:config/mybatis/mapper/*.xml"));
        return sessionFactory.getObject();
    }
}

Spring Data Jpa配置

mssql配置

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef="entityManagerFactorySecondary",
        transactionManagerRef="transactionManagerSecondary",
        basePackages= { "指定mssql repository包名" })
public class MSSqlConfig {
    @Autowired
    @Qualifier("mssqlDataSource")
    private DataSource mssqlDataSource;

    @Bean(name = "entityManagerSecondary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactorySecondary(builder).getObject().createEntityManager();
    }

    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary (EntityManagerFactoryBuilder builder) {
        return builder.dataSource(mssqlDataSource).properties(getVendorProperties(mssqlDataSource))
        //设置实体类所在位置
        .packages("指定实体路径")
        .persistenceUnit("mssqlPersistenceUnit")
        .build();
    }

    @Autowired
    private JpaProperties jpaProperties;

    private Map getVendorProperties(DataSource dataSource) {
        return jpaProperties.getHibernateProperties(dataSource);
    }

    @Bean(name = "transactionManagerSecondary")
    PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
    }

}

Mysql配置

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(entityManagerFactoryRef = "entityManagerFactoryPrimary",
        transactionManagerRef = "transactionManagerPrimary",basePackages = {"指定mysql repository包名"})
public class MySqlConfig {

    @Autowired
    @Qualifier("mysqlDataSource")
    private DataSource mysqlDataSource;

    @Primary
    @Bean(name = "entityManagerPrimary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
    return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
    }
    @Primary
    @Bean(name = "entityManagerFactoryPrimary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) {
        return builder.dataSource(mysqlDataSource).properties(getVendorProperties(mysqlDataSource))
        //设置实体类所在位置
            .packages("指定实体路径")
            .persistenceUnit("mysqlPersistenceUnit")
            .build();
    }
    @Autowired
    private JpaProperties jpaProperties;

    private Map getVendorProperties(DataSource dataSource) {
        return jpaProperties.getHibernateProperties(dataSource);
    }

    @Primary
    @Bean(name = "transactionManagerPrimary")
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    }

}

关键注解的解析

  1. @Configuration

相当于传统的xml配置文件，项目中如果需要依赖第三方的xml文件，仍然建议通过此配置类作为项目的配置主类，通过@ImportResource注解加载xml配置文件。

  1. @Bean

该注解告诉Spring这个方法将会返回一个对象，该对象要注册为Spring应用上下文中的bean

  1. @ConfigurationProperties

读取配置文件信息，读取并自动封装成实体类。这样在代码里使用更加方便。@Value需要单独建立xxxProperties进行映射，效果差不多

  1. @Primary

当系统里面出现多个数据源的时候，需要进行人为指定主数据源

  1. @EnableTransactionManagement

Spring Boot使用事务非常简单，使用该注解开启事务支持，然后在访问数据库的Service方法上添加注解@Transactional便可。

  1. @MapperScan

在数据持久层使用MyBatis时候，使用该注解配置扫描Mapper位置

  1. @Autowired

使用该注解进行自动注入，但是Spring 容器中匹配候选Bean数目必须有且仅有一个。当找不到一个匹配的时候，Spring容器会抛出异常

  1. @Qualifier

在当使用@Autowired产生歧义的时候，可以使用该注解指定对应的name来消除歧义

  1. EnableJpaRepositories

该注解开启对Spring Data JPA Repository的支持

通过以上的配置，项目就可以同时访问多种数据源了。

赶紧记下，别待会儿忘了.