如何使用 ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig, props);在springboot项目启动时候进行数据源初始化，举例

好的，我会尽力回答你的问题。

首先，需要在 pom.xml 文件中添加 sharding-jdbc-spring-boot-starter 依赖，示例代码如下：

<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
    <version>4.1.1</version>
</dependency>

接下来，在 application.properties 文件中配置数据源和分片规则，示例代码如下：

# 配置主数据源
spring.datasource.master.jdbc-url=jdbc:mysql://localhost:3306/db_master?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8
spring.datasource.master.username=root
spring.datasource.master.password=root

# 配置从数据源
spring.datasource.slave.jdbc-url=jdbc:mysql://localhost:3306/db_slave?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8
spring.datasource.slave.username=root
spring.datasource.slave.password=root

# 配置分片规则
spring.shardingsphere.sharding.tables.user.actualDataNodes=ds${0..1}.user${0..1}
spring.shardingsphere.sharding.tables.user.tableStrategy.standard.shardingColumn=user_id
spring.shardingsphere.sharding.tables.user.tableStrategy.standard.preciseAlgorithmClassName=org.apache.shardingsphere.shardingalgorithm.sharding.standard.PreciseShardingAlgorithm
spring.shardingsphere.sharding.tables.user.tableStrategy.standard.rangeAlgorithmClassName=org.apache.shardingsphere.shardingalgorithm.sharding.standard.RangeShardingAlgorithm
spring.shardingsphere.sharding.tables.user.keyGeneratorColumnName=user_id
spring.shardingsphere.sharding.tables.user.keyGenerator.type=SNOWFLAKE
spring.shardingsphere.sharding.tables.user.keyGenerator.column=user_id

最后，在 SpringBoot 启动类中添加 ShardingDataSourceFactory.createDataSource() 方法，示例代码如下：

@SpringBootApplication
public class Application {
 
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
 
    @Bean
    public DataSource dataSource() throws SQLException {
        Map<String, DataSource> dataSourceMap = new HashMap<>();
        dataSourceMap.put("ds_master", DataSourceBuilder.create()
                .url("jdbc:mysql://localhost:3306/db_master?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8")
                .username("root")
                .password("root")
                .build());
        dataSourceMap.put("ds_slave0", DataSourceBuilder.create()
                .url("jdbc:mysql://localhost:3306/db_slave0?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8")
                .username("root")
                .password("root")
                .build());
        dataSourceMap.put("ds_slave1", DataSourceBuilder.create()
                .url("jdbc:mysql://localhost:3306/db_slave1?useSSL=false&serverTimezone=UTC&useUnicode=true&characterEncoding=utf8")
                .username("root")
                .password("root")
                .build());
 
        ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
        shardingRuleConfig.getTableRuleConfigs().add(getUserTableRuleConfiguration());
 
        Properties props = new Properties();
        props.setProperty("sql.show", "true");
 
        return ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig, props);
    }
 
    private TableRuleConfiguration getUserTableRuleConfiguration() {
        TableRuleConfiguration result = new TableRuleConfiguration();
        result.setLogicTable("user");
        result.setActualDataNodes("ds${0..1}.user${0..1}");
        result.setKeyGeneratorColumnName("user_id");
        result.setKeyGenerator(new KeyGeneratorConfiguration("SNOWFLAKE", "user_id"));
        return result;
    }
}

以上代码中，我们创建了 3 个数据源，分别对应主库和两个从库；然后定义了一个分片规则，用于对 user 表进行分片；最后，在 SpringBoot 启动时，调用 ShardingDataSourceFactory.createDataSource() 方法，创建数据源。

希望这个例子能帮助你更好地理解如何使用 ShardingSphere。