Spring Boot Jpa多數據源配置

前言
隨着業務量發展，咱們一般會進行數據庫拆分或是引入其餘數據庫，從而咱們須要配置多個數據源，如：user一個庫，business一個庫。那麼接下來咱們就要考慮怎麼去在spring boot中實現多個數據源的配置。

×××

實現
建表
首先是建表語句，咱們要創建兩個數據庫，並各庫內新建一張表
user表
mysql> use user；
mysql> select * from user;
+----+-------+----------+
| id | name | password |
+----+-------+----------+
| 1 | 用戶A | ** |
+----+-------+----------+
1 row in set
business表
mysql> use business；
mysql> select * from business;
+----+-------+-------------+
| id | name | description |
+----+-------+-------------+
| 1 | 業務A | 業務A描述 |
+----+-------+-------------+
1 row in setbr/>接下來咱們經過代碼實現對兩個庫內的多張表進行查詢。
配置
首先，建立一個Spring配置類，定義兩個DataSource用來讀取application.yml中的不一樣配置。本文中，咱們user作爲主數據源，主數據源配置爲spring.datasource.user開頭的配置，business數據源配置爲spring.datasource.business開頭的配置。
@Configuration
public class DataSourceConfig {br/>@Primary
@Bean(name = "userDataSource")br/>@Qualifier("userDataSource")
@ConfigurationProperties(prefix = "spring.datasource.user")
public DataSource userDataSource() {
return DataSourceBuilder.create().build();
}
@Bean(name = "businessDataSource")br/>@Qualifier("businessDataSource")
@ConfigurationProperties(prefix = "spring.datasource.business")
public DataSource businessDataSource() {
return DataSourceBuilder.create().build();
}
}
對應的配置文件application.yml以下：
spring:
datasource:
user:
driver-class-name: com.mysql.jdbc.Driver
jdbc-url: jdbc:mysql://localhost:3306/user
username: root
password: 123456
business:
driver-class-name: com.mysql.jdbc.Driver
jdbc-url: jdbc:mysql://localhost:3306/business
username: root
password: 123456br/>接下來咱們對各數據源進行jpa的配置
主數據源User
@Configuration
@EnableTransactionManagementbr/>@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactoryUser",
transactionManagerRef = "transactionManagerUser",
//設置Repository所在位置
basePackages = {"com.ppc.spring.example.jpamultidatasource.repository.user"})
public class UserConfig {br/>@Autowired
@Qualifier("userDataSource")
private DataSource userDataSource;br/>@Autowired
private JpaProperties jpaProperties;br/>@Autowired
private HibernateProperties hibernateProperties;br/>@Primary
@Bean(name = "entityManagerUser")
public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
return entityManagerFactoryUser(builder).getObject().createEntityManager();br/>}
@Primary
@Bean(name = "entityManagerFactoryUser")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryUser(EntityManagerFactoryBuilder builder) {
return builder
.dataSource(userDataSource)
//設置entity所在位置
.packages("com.ppc.spring.example.jpamultidatasource.entity.user")
.persistenceUnit("userPersistenceUnit")
.properties(getVendorProperties())
.build();
}
private Map<String, Object> getVendorProperties() {
return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());br/>}
@Primary
@Bean(name = "transactionManagerUser")
public PlatformTransactionManager transactionManagerUser(EntityManagerFactoryBuilder builder) {
return new JpaTransactionManager(entityManagerFactoryUser(builder).getObject());br/>}
}
其餘數據源business
@Configuration
@EnableTransactionManagementbr/>@EnableJpaRepositories(
entityManagerFactoryRef = "entityManagerFactoryBusiness",
transactionManagerRef = "transactionManagerBusiness",
//設置repository所在位置
basePackages = {"com.ppc.spring.example.jpamultidatasource.repository.business"})
public class BusinessConfig {br/>@Autowired
@Qualifier("businessDataSource")
private DataSource businessDataSource;br/>@Autowired
private JpaProperties jpaProperties;br/>@Autowired
private HibernateProperties hibernateProperties;
@Bean(name = "entityManagerBusiness")
public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
return entityManagerFactoryBusiness(builder).getObject().createEntityManager();
}
@Bean(name = "entityManagerFactoryBusiness")
public LocalContainerEntityManagerFactoryBean entityManagerFactoryBusiness(EntityManagerFactoryBuilder builder) {
return builder
.dataSource(businessDataSource)
.properties(getVendorProperties())
//設置實體類所在位置
.packages("com.ppc.spring.example.jpamultidatasource.entity.business")
.persistenceUnit("businessPersistenceUnit")
.build();
}
private Map<String, Object> getVendorProperties() {
return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
}
@Bean(name = "transactionManagerBusiness")
PlatformTransactionManager transactionManagerBusiness(EntityManagerFactoryBuilder builder) {
return new JpaTransactionManager(entityManagerFactoryBusiness(builder).getObject());
}
}
配置中須要注意如下幾點：
Spring Boot 1.5.x
private Map<String, String> getVendorProperties() {
return jpaProperties.getHibernateProperties(userDataSource);
}
Spring Boot 2.0.x
private Map<String, Object> getVendorProperties() {
return jpaProperties.getHibernateProperties(new HibernateSettings());
}
Spring Boot 2.1.0參見上文代碼，引進了HibernateProperties。同時，在Spring Boot 2.1.0中默認的mysql-connector-java版本爲8.0.13，鏈接低版本mysql配置上比較繁瑣，建議在配置文件中手動指定相應版本，如本文中指定5.1.46這個版本。
runtimeOnly('mysql:mysql-connector-java:5.1.46')
repository、entity的所在位置，要和實際保存的位置一致。

主數據源的一些配置須要添加@Primary做爲spring默認的首選項，其餘數據源無需添加該註解。

經過查看相關源碼咱們看到Spring Boot中JpaProperties的代碼一直在調整，這裏咱們將properties相關代碼單獨提取出做爲一個單獨的方法getVendorProperties展現版本間的區別。其中：br/>查詢
完成了全部的配置，接下來咱們就能夠開始寫個簡單代碼驗證咱們配置了
@RestController
@SpringBootApplication
public class JpaMultiDatasourceApplication {br/>@Autowired
UserRepository userRepository;br/>@Autowired
Busine***epository busine***epository;
public static void main(String[] args) {
SpringApplication.run(JpaMultiDatasourceApplication.class, args);br/>}
@GetMapping("/user/{id}")
public User getUser(@PathVariable Long id) {
return userRepository.findById(id).orElse(null);br/>}
@GetMapping("/business/{id}")
public Business getBusiness(@PathVariable Long id) {
return busine***epository.findById(id).orElse(null);
}
}
咱們對外暴露了兩個接口，分別訪問user表、business表確承認以正常獲取數據。查詢結果以下：
請求：http://localhost:8080/user/1
結果：{"id":1,"name":"用戶A","password":"**"}
請求：http://localhost:8080/business/1
結果：{"id":1,"name":"業務A","description":"業務A描述"}
就此，咱們雙數據源的配置和驗證工做就完成了。