如何在Spring引導中爲MySQL數據庫指定默認模式Jdbc

Question

我們從Spring引導連接到多個數據庫。

application.properties：

datasource.target.url=jdbc:mysql://localhost:3306/db_test_1?useSSL=false 
datasource.target.driver-class-name=com.mysql.jdbc.Driver 

datasource.origin.url=jdbc:mysql://localhost:3306/db_test_2?useSSL=false 
datasource.origin.driver-class-name=com.mysql.jdbc.Driver 

數據庫配置：

@Configuration 
public class DatabaseConfig { 

    @Bean(name = "originJdbcTemplate") 
    public JdbcTemplate originJdbcTemplate() { 
     return new JdbcTemplate(originDataSource()); 
    } 

    @Bean(name = "targetJdbcTemplate") 
    public JdbcTemplate targetJdbcTemplate() { 
     return new JdbcTemplate(targetDataSource()); 
    } 

    @Bean 
    @Primary 
    @ConfigurationProperties("datasource.origin") 
    public DataSourceProperties originDataSourceProperties() { 
     return new DataSourceProperties(); 
    } 

    @Bean 
    @Primary 
    @ConfigurationProperties("datasource.origin") 
    public DataSource originDataSource() { 
     return originDataSourceProperties().initializeDataSourceBuilder().build(); 
    } 

    @Bean 
    @ConfigurationProperties("datasource.target") 
    public DataSourceProperties targetDataSourceProperties() { 
     return new DataSourceProperties(); 
    } 

    @Bean 
    @ConfigurationProperties("datasource.target") 
    public DataSource targetDataSource() { 
     return targetDataSourceProperties().initializeDataSourceBuilder().build(); 
    } 

} 

我們使用了Spring JDBC模板，我們必須明確命名的每個查詢的模式，即使我們已經定義的模式名稱在應用程序屬性的上面的url。 e.g： 沒有架構名稱查詢不起作用

select * from db_test_1.user //works with schema name 
select * from user //doesn't work 

按本SO Answer 我應該使用Connection.setCatalog()，我該怎麼做，在Spring配置？

Answer 1

通過使用委派的數據源

class DefaultSchemaDelegatingDS extends DelegatingDataSource { 
    private final String catalogName; 

    public DefaultSchemaDelegatingDS(final String catalogName, final DataSource dataSource) { 
     super(dataSource); 
     this.catalogName = catalogName; 
    } 

    @Override 
    public Connection getConnection() throws SQLException { 
     final Connection connection = super.getConnection(); 
     connection.setCatalog(this.catalogName); 
     return connection; 
    } 
} 

然後在DatabaseConfig

@Configuration 
public class DatabaseConfig { 

    @Value("${datasource.target.default_schema}") 
    private String defaultTargetSchema; 

    @Value("${datasource.origin.default_schema}") 
    private String defaultOriginSchema; 

    @Bean(name = "originJdbcTemplate") 
    public JdbcTemplate originJdbcTemplate() { 
     return new JdbcTemplate(originDataSource()); 
    } 

    @Bean(name = "targetJdbcTemplate") 
    public JdbcTemplate targetJdbcTemplate() { 
     return new JdbcTemplate(targetDataSource()); 
    } 

    @Bean 
    @Primary 
    @ConfigurationProperties("datasource.origin") 
    public DataSourceProperties originDataSourceProperties() { 
     return new DataSourceProperties(); 
    } 

    @Bean 
    @Primary 
    @ConfigurationProperties("datasource.origin") 
    public DataSource originDataSource() { 
     final DataSource ds = originDataSourceProperties().initializeDataSourceBuilder().build(); 
     return new DefaultSchemaDelegatingDS(defaultOriginSchema, ds); 
    } 

    @Bean 
    @ConfigurationProperties("datasource.target") 
    public DataSourceProperties targetDataSourceProperties() { 
     return new DataSourceProperties(); 
    } 

    @Bean 
    @ConfigurationProperties("datasource.target") 
    public DataSource targetDataSource() { 
     final DataSource ds = targetDataSourceProperties().initializeDataSourceBuilder().build(); 
     return new DefaultSchemaDelegatingDS(defaultTargetSchema, ds); 
    } 
} 

的另一種方法不使用DelegatingDatasource是簡單地添加

jdbcTemplate.getDataSource().getConnection().setCatalog(catalogName); 

例如，

@Bean(name = "originJdbcTemplate") 
public JdbcTemplate originJdbcTemplate() throws SQLException { 
    JdbcTemplate jdbcTemplate = new JdbcTemplate(originDataSource()); 
    jdbcTemplate.getDataSource().getConnection().setCatalog(defaultOriginSchema); 
    return jdbcTemplate; 
}