Question

我正在创建一个多租户Spring Boot-JPA应用程序。

在此应用程序中，我想使用通过API请求作为标头发送的数据库名称连接到MySQL数据库。

我在线检查了许多多租户项目示例，但仍然找不到解决方案。

有人可以建议我这样做吗？

Answer 1

您可以使用AbstractRoutingDataSource来实现。 AbstractRoutingDataSource需要信息来知道要路由到哪个实际DataSource（称为 Context ），这是由determineCurrentLookupKey()方法提供的。使用here中的示例。

定义上下文，例如：

public enum ClientDatabase {
    CLIENT_A, CLIENT_B
}

然后，您需要定义将在determineCurrentLookupKey()

中使用的Context Holder。

public class ClientDatabaseContextHolder {

    private static ThreadLocal<ClientDatabase> CONTEXT = new ThreadLocal<>();

    public static void set(ClientDatabase clientDatabase) {
        Assert.notNull(clientDatabase, "clientDatabase cannot be null");
        CONTEXT.set(clientDatabase);
    }

    public static ClientDatabase getClientDatabase() {
        return CONTEXT.get();
    }

    public static void clear() {
        CONTEXT.remove();
    }
}

然后您可以像下面这样扩展AbstractRoutingDataSource：

public class ClientDataSourceRouter extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return ClientDatabaseContextHolder.getClientDatabase();
    }
}

最后，DataSource bean配置：

@Bean
public DataSource clientDatasource() {
    Map<Object, Object> targetDataSources = new HashMap<>();
    DataSource clientADatasource = clientADatasource();
    DataSource clientBDatasource = clientBDatasource();
    targetDataSources.put(ClientDatabase.CLIENT_A, 
      clientADatasource);
    targetDataSources.put(ClientDatabase.CLIENT_B, 
      clientBDatasource);

    ClientDataSourceRouter clientRoutingDatasource 
      = new ClientDataSourceRouter();
    clientRoutingDatasource.setTargetDataSources(targetDataSources);
    clientRoutingDatasource.setDefaultTargetDataSource(clientADatasource);
    return clientRoutingDatasource;
}

Answer 2

https://github.com/wmeints/spring-multi-tenant-demo

按照这个逻辑，我现在可以解决它。一些版本需要升级，代码也需要升级。

Spring Boot版本已更改。

org.springframework.boot 弹簧启动启动器父母 2.1.0。发布
MySQL版本已被删除。

MultitenantConfiguration.java中的一些小变化

@Configuration
public class MultitenantConfiguration {

@Autowired
private DataSourceProperties properties;

/**
 * Defines the data source for the application
 * @return
 */
@Bean
@ConfigurationProperties(
        prefix = "spring.datasource"
)
public DataSource dataSource() {
    File[] files = Paths.get("tenants").toFile().listFiles();
    Map<Object,Object> resolvedDataSources = new HashMap<>();

    if(files != null) {
        for (File propertyFile : files) {
            Properties tenantProperties = new Properties();
            DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create(this.getClass().getClassLoader());

            try {
                tenantProperties.load(new FileInputStream(propertyFile));

                String tenantId = tenantProperties.getProperty("name");

                dataSourceBuilder.driverClassName(properties.getDriverClassName())
                        .url(tenantProperties.getProperty("datasource.url"))
                        .username(tenantProperties.getProperty("datasource.username"))
                        .password(tenantProperties.getProperty("datasource.password"));

                if (properties.getType() != null) {
                    dataSourceBuilder.type(properties.getType());
                }

                resolvedDataSources.put(tenantId, dataSourceBuilder.build());
            } catch (IOException e) {
                e.printStackTrace();

                return null;
            }
        }
    }

    // Create the final multi-tenant source.
    // It needs a default database to connect to.
    // Make sure that the default database is actually an empty tenant database.
    // Don't use that for a regular tenant if you want things to be safe!
    MultitenantDataSource dataSource = new MultitenantDataSource();
    dataSource.setDefaultTargetDataSource(defaultDataSource());
    dataSource.setTargetDataSources(resolvedDataSources);

    // Call this to finalize the initialization of the data source.
    dataSource.afterPropertiesSet();

    return dataSource;
}

/**
 * Creates the default data source for the application
 * @return
 */
private DataSource defaultDataSource() {
    DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create(this.getClass().getClassLoader())
            .driverClassName(properties.getDriverClassName())
            .url(properties.getUrl())
            .username(properties.getUsername())
            .password(properties.getPassword());

    if(properties.getType() != null) {
        dataSourceBuilder.type(properties.getType());
    }

    return dataSourceBuilder.build();
}

}

此更改是由于DataSourceBuilder已移至另一路径并且其构造函数已更改。

还像这样在application.properties中更改了MySQL驱动程序类名称

spring.datasource.driver-class-name = com.mysql.jdbc.Driver

如何根据REST API请求中的标头连接到多个MySQL数据库

2 个答案: