[Go] Spring boot configuration multiple datasource

[From] https://www.liaoxuefeng.com/article/001484212576147b1f07dc0ab9147a1a97662a0bd270c20000

Spring Boot Configuration multiple datasource

Liaoche/Programming/ 1-13 10:11/read: 14041

With spring boot, the configuration is easy by default DataSource . Spring boot will automatically configure good one for us DataSource .

If a application.yml related configuration is specified in spring.datasource , Spring boot uses that configuration to create one DataSource . If application.yml no related configuration is specified in spring.datasource , Spring boot will search the classpath for the jar packages of memory databases such as H2, HSQLDB, and, if found, automatically configure a memory database DataSource , so We just need to introduce the jar package. For example, configure a HSQLDB data source:

<dependency>    <groupId>org.hsqldb</groupId> <artifactId>hsqldb</artifactId> <scope>runtime</scope></dependency>

However, in some cases, if we need to configure multiple data sources, how should we configure them in spring boot?

We use JDBC as an example to demonstrate how to configure two in spring boot DataSource . Correspondingly, we will create two JdbcTemplate beans, each using these two data sources.

First, we must application.yml declare the configuration of two data sources in, one using spring.datasource , the other using spring.second-datasource :

SpringApplication:Namedata-MultidatasourceDataSourcedriver-class-name: org.hsqldb.jdbc url: jdbc:hsqldb:mem< span class= "pseudo" >:d B1 username: sa password: second-datasource: driver-class-name: org.hsqldb.jdbc . Jdbcdriver url: jdbc:hsqldb:mem< span class= "pseudo" >:d B2 username: sa password:   

DataSourceall two use HSQLDB, but the database is different. In addition, all necessary configurations cannot be omitted when using multiple data sources.

Second, we need to create two of our own DataSource beans, one of which is labeled @Primary , and the other named secondDatasource :

  @Configuration public class someconfiguration { @Bean  @Primary  @ConfigurationProperties (prefix =  "Spring.datasource") public DataSource primarydatasource () {return datasourcebuilder.create (). build (); }  @Bean (name = @ Configurationproperties (prefix =  "Spring.second-datasource") public DataSource Seconddatasource () {return datasourcebuilder.create (). build ();}}    

For each one DataSource , we must @ConfigurationProperties(prefix = "xxx") prefix by specifying the configuration item.

Immediately after that, we created two JdbcTemplate beans, one of which was labeled, the @Primary other named secondJdbcTemplate , and each used the corresponding DataSource :

@Bean@Primarypublic JdbcTemplate primaryJdbcTemplate(DataSource dataSource) {    return new JdbcTemplate(dataSource);}@Bean(name = "secondJdbcTemplate")public JdbcTemplate secondJdbcTemplate(@Qualifier("secondDatasource") DataSource dataSource) { return new JdbcTemplate(dataSource);}

Notice that secondJdbcTemplate at the time of creation, the incoming DataSource must be @Qualifier("secondDatasource") declared so that the second can be used DataSource .

Now, we've created two of these JdbcTemplate Bean . Where we need to use JdbcTemplate the first one, we inject directly:

@Componentpublic class SomeService { @Autowired JdbcTemplate jdbcTemplate;}

When we need to use JdbcTemplate the second place, we need to identify the injection @Qualifier("secondJdbcTemplate") :

@Componentpublic class AnotherService { @Autowired @Qualifier("secondJdbcTemplate") JdbcTemplate secondJdbcTemplate;}

In this way, we can operate on different data sources and in different ways JdbcTemplate .

Precautions

When there are more than one bean of the same type, for example, multiple, multiple, it is DataSource JdbcTemplate strongly recommended to always use one of the @Primary beans identified as "primary", using @Autowired injection to first use the bean that is marked @Primary .

Other beans of the same type, each of which needs to be @Bean(name="xxx") identified by name, and the @Autowired name of the @Qualifier("xxx") injected Bean is specified with the injection.

For a complete sample project source code, please refer to:

Https://github.com/michaelliao/springcloud/tree/master/data-multidatasource

[Go] Spring boot configuration multiple datasource