多个数据源的 Hikaricp 配置

Posted 2023-04-11

【中文标题】多个数据源的 Hikaricp 配置

【英文标题】：Hikaricp configuration for multiple datasources

【发布时间】：2019-01-09 08:04:34

【问题描述】：

我有一个多数据库应用程序。用户可以在登录页面选择数据库。

然后数据库正在路由选定的数据库，感谢 Spring 的 AbstractRoutingDataSource。

我想使用 HikariCP，但它需要 dataSourceUrl。但我的数据源 URL 会动态变化。如何为多个数据库配置 Hikaricp？

文件application.properties：

#database1 properties
app.database1.connection.url = url1
app.database1.connection.username = sameusername
app.database1.connection.password = samepassword
#database2 properties
app.database2.connection.url = url2
app.database2.connection.username = sameusername
app.database2.connection.password = samepassword

我的Datasource配置类示例：

public class DataSourceConfiguration 

    @Autowired(required = false)
    private PersistenceUnitManager persistenceUnitManager;

    @Bean
    @ConfigurationProperties(prefix = "app.database1.connection")
    public DataSource database1DataSource() 
        return DataSourceBuilder.create().build();
    

    @Bean
    @ConfigurationProperties(prefix = "app.database2.connection")
    public DataSource database2DataSource() 
        return DataSourceBuilder.create().build();
    

    @Bean
    @Primary
    public DataSource appDataSource() 
        DataSourceRouter router = new DataSourceRouter();
        final HashMap<Object, Object> map = new HashMap<>(3);
        map.put(DatabaseEnvironment.DATABASE1, database1DataSource());
        map.put(DatabaseEnvironment.DATABASE2, database2DataSource());
        router.setTargetDataSources(map);
        return router;
    

    @Bean
    @Primary
    @ConfigurationProperties("app.connection.jpa")
    public JpaProperties appJpaProperties() 
        return new JpaProperties();
    

    private JpaVendorAdapter createJpaVendorAdapter(JpaProperties jpaProperties) 
        AbstractJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
        adapter.setShowSql(jpaProperties.isShowSql());
        adapter.setDatabase(jpaProperties.getDatabase());
        adapter.setDatabasePlatform(jpaProperties.getDatabasePlatform());
        adapter.setGenerateDdl(jpaProperties.isGenerateDdl());
        return adapter;
    

我的会话范围类而不是上下文持有者：

@Component
@Scope(value = "session", proxyMode = ScopedProxyMode.TARGET_CLASS)
public class PreferredDatabaseSession implements Serializable 

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    private DatabaseEnvironment preferredDb;

    public DatabaseEnvironment getPreferredDb() 
        return preferredDb;
    

    public void setPreferredDb(DatabaseEnvironment preferredDb) 
        this.preferredDb = preferredDb;
    

【问题讨论】：

你说DB url动态变化是什么意思？ application.properties 文件中的url1、url2 等是常量吧？

url1 和 url2 ara 常量。但是，当用户选择 database1 AbstractRoutingDataSource 将用户路由到 url1 时，当他选择 database2 时，它会转到 url2

【参考方案1】：

如果我正确理解您的要求，您打算定义两个数据源，并且对于给定请求，您希望根据某些条件将查询路由到特定数据源。

解决办法是：

文件application.properties

#database1 properties
app.database1.connection.url = url1
app.database1.connection.username = username1
app.database1.connection.password = password1
#database2 properties
app.database2.connection.url = url2
app.database2.connection.username = username2
app.database2.connection.password = password2
#default
default.datasource.key=dataSource1

文件 CommonRoutingDataSource.java

public class CommonRoutingDataSource extends AbstractRoutingDataSource 

    @Override
    protected Object determineCurrentLookupKey() 
        return DataSourceContextHolder.getDataSourceName();
    

    public void initDataSources(final DataSource dataSource1, final DataSource dataSource2,
            final String defaultDataSourceKey) 
        final Map<Object, Object> dataSourceMap = new HashMap<Object, Object>();
        dataSourceMap.put("dataSource1", dataSource1);
        dataSourceMap.put("dataSource2", dataSource2);
        this.setDefaultTargetDataSource(dataSourceMap.get(defaultDataSourceKey));
        this.setTargetDataSources(dataSourceMap);
    

文件 DataSourceContextHolder.java

public class DataSourceContextHolder 

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();

    private DataSourceContextHolder() 
        // Private no-op constructor
    

    public static final void setDataSourceName(final String dataSourceName) 
        Assert.notNull(dataSourceName, "dataSourceName cannot be null");
        contextHolder.set(dataSourceName);
    

    public static final String getDataSourceName() 
        return contextHolder.get();
    

    public static final void clearDataSourceName() 
        contextHolder.remove();
    

文件 DataSourceConfig.java

public class DataSourceConfig 

    @Autowired
    private Environment env;

    @Autowired
    @Bean(name = "dataSource")
    public DataSource getDataSource(final DataSource dataSource1, final DataSource dataSource2) 
        final CommonRoutingDataSource dataSource = new CommonRoutingDataSource();
        dataSource.initDataSources(dataSource1, dataSource2, env.getProperty("default.datasource.key"));
        return dataSource;
    

    @Bean(name = "dataSource1")
    public DataSource getDataSource1() throws SQLException 
        // The exact DataSource class imported shall be as per your requirement - HikariCP, or Tomcat etc.
        final DataSource dataSource = new DataSource();
        dataSource.setDriverClassName();
        dataSource.setUrl(env.getProperty("app.database1.connection.url"));
        // Set all data source attributes from the application.properties file
        return dataSource;
    

    @Bean(name = "dataSource2")
    public DataSource getDataSource2() throws SQLException 
        // The exact DataSource class imported shall be as per your requirement - HikariCP, or Tomcat etc.
        final DataSource dataSource = new DataSource();
        dataSource.setDriverClassName();
        dataSource.setUrl(env.getProperty("app.database2.connection.url"));
        // set all data source attributes from the application.properties file
        return dataSource;
    

现在，在您的代码中的某处（Aspect 或 Controller），您需要有条件地动态设置数据源：

DataSourceContextHolder.setDataSourceName("dataSource1");

注意：最好将数据源名称声明为枚举，而不是字符串“dataSource1”、“dataSource2”等。

【讨论】：

我没有在 DataSourceContextHolder 上使用 ThreadLocal。而不是它，我使用 Session 范围类。我将它附加到问题正文中。