有時候，一個系統的功能，需要兩個或兩個以上的數據庫，

在Spring Boot 中要如何配置？ How to?

#primary
primary.spring.datasource.jdbc-url=jdbc:mysql://localhost:3316/test1
primary.spring.datasource.username=root
primary.spring.datasource.password=root
primary.spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver


#secondary
secondary.spring.datasource.jdbc
 
-url=jdbc:mysql://localhost:3316/test2
secondary.spring.datasource.username=root
secondary.spring.datasource.password=root
secondary.spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

新建一個類DataSourceConfig

@Configuration
public class DataSourceConfig {

    @Bean(name = "primaryDataSource")
    @Qualifier(
 
"primaryDataSource")
    @Primary
    @ConfigurationProperties(prefix="primary.spring.datasource")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix
 
="secondary.spring.datasource")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }

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

    @Bean(name = "secondaryJdbcTemplate")
    public JdbcTemplate secondaryJdbcTemplate(@Qualifier("secondaryDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

}

之後在運用的時候，註意@Qualifier

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class ApplicationTests {

    @Autowired
    @Qualifier("primaryJdbcTemplate")
    protected JdbcTemplate jdbcTemplate1;

    @Autowired
    @Qualifier("secondaryJdbcTemplate")
    protected JdbcTemplate jdbcTemplate2;

    @Before
    public void setUp() {
        jdbcTemplate1.update("DELETE  FROM  USER ");
        jdbcTemplate2.update("DELETE  FROM  USER ");
    }

    @Test
    public void test() throws Exception {

        // 往第一個數據源中插入兩條數據
        jdbcTemplate1.update("insert into user(id,name,age) values(?, ?, ?)", 1, "aaa", 20);
        jdbcTemplate1.update("insert into user(id,name,age) values(?, ?, ?)", 2, "bbb", 30);
｝｝

java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName.

修改application.xml中的數據庫的url， 用spring.datasource.jdbc-url，而不是通常使用的spring.datasource.url。

之前用的如下截圖，總是報錯

Spring Boot多數據源配置與使用