Spring Boot+Jpa多数据源配置的完整步骤

Spring Boot+Jpa多数据源配置的完整步骤

关于

有时候，随着业务的发展，项目关联的数据来源会变得越来越复杂，使用的数据库会比较分散，这个时候就会采用多数据源的方式来获取数据。另外，多数据源也有其他好处，例如分布式数据库的读写分离，集成多种数据库等等。

下面分享我在实际项目中配置多数据源的案例。话不多说了，来一起看看详细的介绍吧

步骤

1.application.yml文件中，配置数据库源。这里primary是主库，secondary是从库。

server:

port: 8089

# 多数据源配置

#primary

spring:

primary:

datasource:

url: jdbc:mysql://127.0.0.1:3306/database1?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai

username: root

password: ******

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

#secondary

secondary:

datasource:

url: jdbc:mysql://127.0.0.1:3306/database1?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8&useSSL=false&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai

username: root

password: ******

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

jpa:

hibernate:

primary-dialect: org.hibernate.dialect.MySQL5Dialect

secondary-dialect: org.hibernate.dialect.MySQL5Dialect

open-in-view: true

show-sql: true

2.创建一个Spring配置类，其中spring.primary.datasource的路径参考yml文件的配置。

@Configuration

public class DataSourceConfig {

@Bean(name = "primaryDataSource")

@Qualifier("primaryDataSource")

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

public DataSource primaryDataSource() {

return DataSourceBuilder.create().build();

}

@Bean(name = "secondaryDataSource")

@Qualifier("secondaryDataSource")

@Primary

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

public DataSource secondaryDataSource() {

return DataSourceBuilder.create().build();

}

}

3.分别创建主库、从库的配置类。

注意：entity包和dao包的配置，以及@Primary注解指定主库。

主库配置类：

@Configuration

@EnableTransactionManagement

@EnableJpaRepositories(

entityManagerFactoryRef = "entityManagerFactoryPrimary",

transactionManagerRef = "transactionManagerPrimary",

basePackages = {"com.infinitus.yunxiao_data.dao.primary"}) //设置Repository所在位置

public class PrimaryConfig {

@Autowired

private JpaProperties jpaProperties;

@Autowired

@Qualifier("primaryDataSource")

private DataSource primaryDataSource;

@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(primaryDataSource)

.properties(getVendorProperties(primaryDataSource))

.packages("com.infinitus.yunxiao_data.entity.primary") //设置实体类所在位置

.persistenceUnit("primaryPersistenceUnit")

.build();

}

private Map getVendorProperties(DataSource dataSource) {

return jpaProperties.getHibernateProperties(dataSource);

}

@Primary

@Bean(name = "transactionManagerPrimary")

public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {

return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());

}

}

从库的配置类：

@Configuration

@EnableTransactionManagement

@EnableJpaRepositories(

entityManagerFactoryRef = "entityManagerFactorySecondary",

transactionManagerRef = "transactionManagerSecondary",

basePackages = {"com.infinitus.yunxiao_data.dao.secondary"}) //设置Repository所在位置

public class SecondaryConfig {

@Autowired

private JpaProperties jpaProperties;

@Autowired

@Qualifier("secondaryDataSource")

private DataSource secondaryDataSource;

@Bean(name = "entityManagerSecondary")

public EntityManager entityManager(EntityManagerFactoryBuilder builder) {

return entityManagerFactorySecondary(builder).getObject().createEntityManager();

}

@Bean(name = "entityManagerFactorySecondary")

public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {

return builder

.dataSource(secondaryDataSource)

.properties(getVendorProperties(secondaryDataSource))

.packages("com.infinitus.yunxiao_data.entity.secondary") //设置实体类所在位置

viaLMnS .persistenceUnit("primaryPersistenceUnit")

.build();

}

private Map getVendorProperties(DataSource dataSource) {

return jpaProperties.getHibernateProperties(dataSource);

}

@Bean(name = "transactionManagerSecondary")

PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {

return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());

}

}

4.分别创建主、从库dao类。

主dao：

@Repository

public interface PrimaryRepository extends JpaRepository {

@Query(value = "SELECT p FROM PrimaryEntity p")

List queryList();

}

从dao：

@Repository

public interface SecondaryRepository extends JpaRepository {

@Query(value = "SELECT p FROM SecondaryEntity p")

List queryList();

}

5.分别创建主、从库entity类。

主entity：

@Entity

@Table(name = "holiday_scheme")

@EntityListeners(AuditingEntityListener.class)

public class PrimaryEntity extends AbstractPersistable {

@Column(name = "date")

public String date;

@Column(name = "hour")

public String hour;

@Column(name = "holiday")

public String holiday;

@Column(name = "holiday_explain")

public String holiday_explain;

public String getDate() {

return date;

}

public void setDate(String date) {

this.date = date;

}

public String getHour() {

return hour;

}

public void setHour(String hour) {

this.hour = hour;

}

public String getHoliday() {

return holiday;

}

public void setHoliday(String holiday) {

this.holiday = holiday;

}

public String getHoliday_explain() {

return holiday_explain;

}

public void setHoliday_explain(String holiday_explain) {

this.holiday_explain = holiday_explain;

}

@Override

public String toString() {

return "PrimaryEntity{" +

"date='" + date + '\'' +

", hour='" + hour + '\'' +

", holiday='" + holiday + '\'' +

", holiday_explain='" + holiday_explain + '\'' +

'}';

}

}

从entity：

@Entity

@Table(name = "active_dashboards")

@EntityListeners(AuditingEntityListener.class)

public class SecondaryEntity extends AbstractPersistable {

@Column(name = "dashboard_id")

public String dashboard_id;

@Column(name = "user_id")

public String user_id;

@Column(name = "order_index")

public String order_index;

public String getDashboard_id() {

return dashboard_id;

}

public void setDashboard_id(String dashboard_id) {

this.dashboard_id = dashboard_id;

}

public String getUser_id() {

return user_id;

}

public void setUser_id(String user_id) {

this.user_id = user_id;

}

public String getOrder_index() {

return order_index;

}

public void setOrder_index(String order_index) {

this.order_index = order_index;

}

@Override

public String toString() {

return "SecondaryEntity{" +

"dashboard_id='" + dashboard_id + '\'' +

", user_id='" + user_id + '\'' +

", order_index='" + order_index + '\'' +

'}';

}

}

6.controller请求获取不同数据库的数据。

@RestController

@RequestMapping("/database")

public class MailController {

private final Logger logger = LoggerFactory.getLogger(this.getClass());

@Autowired

PrimaryRepository primaryRepository;

@Autowired

SecondaryRepository secondaryRepository;

@RequestMapping("/primary")

@ResponseBody

public String primary() {

return primaryRepository.queryList().toString();

}

@RequestMapping("/secondary")

@ResponseBody

public String secondary() {

return secondaryRepository.queryList().toString();

}

}

注意

下面提两个在配置多数据源时遇到的坑点，一不注意就掉坑了。

1.Application类不需要配置@EnableJpaRepositories注解，会报如下错误。

A component required a bean named 'entityManagerFactory' that could not be f

2.注意检查dao类，获取数据的方法上格式是否正确，有没有某个字段是表中不存在的，避免启动异常。如下，SecondaryEntity表中是不存在job_name字段的，所以注释掉才能启动成功等。

//@Query(value = "SELECT p FROM SecondaryEntity p where p.job_name = ?1")

//List queryOdcRecord(String job_name);

总结

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