ShardingSphere如何完成与Spring家族无缝整合的？

public class SpringShardingDataSource extends ShardingDataSource {

    public SpringShardingDataSource(final Map<String, DataSource> dataSourceMap, final ShardingRuleConfiguration shardingRuleConfiguration, final Properties props) throws SQLException {
        super(dataSourceMap, new ShardingRule(shardingRuleConfiguration, dataSourceMap.keySet()), props);
    }
}

public final class ShardingDataSourceBeanDefinitionParserTag {
    public static final String ROOT_TAG = "data-source";
    public static final String SHARDING_RULE_CONFIG_TAG = sharding-rule";
    public static final String PROPS_TAG = "props";
    public static final String DATA_SOURCE_NAMES_TAG = "data-source-names";
    public static final String DEFAULT_DATA_SOURCE_NAME_TAG = "default-data-source-name";
    public static final String TABLE_RULES_TAG = "table-rules"; 
    …
}

<sharding:data-source id="shardingDataSource">
        <sharding:sharding-rule data-source-names="ds0,ds1">
            <sharding:table-rules>
                <sharding:table-rule …/>
                <sharding:table-rule …/>
                …
            </sharding:table-rules>
            …
        </sharding:sharding-rule>
</sharding:data-source>

<xsd:schema xmlns="http://shardingsphere.apache.org/schema/shardingsphere/sharding"
            xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:beans="http://www.springframework.org/schema/beans"
            xmlns:encrypt="http://shardingsphere.apache.org/schema/shardingsphere/encrypt"
            targetNamespace="http://shardingsphere.apache.org/schema/shardingsphere/sharding"
            elementFormDefault="qualified" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://shardingsphere.apache.org/schema/shardingsphere/encrypt http://shardingsphere.apache.org/schema/shardingsphere/encrypt/encrypt.xsd">
    <xsd:import namespace="http://www.springframework.org/schema/beans" schemaLocation="http://www.springframework.org/schema/beans/spring-beans.xsd" />
    <xsd:import namespace="http://shardingsphere.apache.org/schema/shardingsphere/encrypt" schemaLocation="http://shardingsphere.apache.org/schema/shardingsphere/encrypt/encrypt.xsd"/>
    <xsd:element name="data-source">
        <xsd:complexType>
            <xsd:all>
                <xsd:element ref="sharding-rule" />
                <xsd:element ref="props" minOccurs="0" />
            </xsd:all>
            <xsd:attribute name="id" type="xsd:string" use="required" />
        </xsd:complexType>
    </xsd:element>
    …
</xsd:schema>

public final class ShardingNamespaceHandler extends NamespaceHandlerSupport {
  @Overridepublic void init() {        registerBeanDefinitionParser(ShardingDataSourceBeanDefinitionParserTag.ROOT_TAG, new ShardingDataSourceBeanDefinitionParser());  registerBeanDefinitionParser(ShardingStrategyBeanDefinitionParserTag.STANDARD_STRATEGY_ROOT_TAG, new ShardingStrategyBeanDefinitionParser());  …   } }

@Override
protected AbstractBeanDefinition parseInternal(final Element element, final ParserContext parserContext) {
        //构建针对 SpringShardingDataSource 的 BeanDefinitionBuilder
        BeanDefinitionBuilder factory = BeanDefinitionBuilder.rootBeanDefinition(SpringShardingDataSource.class);
       //解析构造函数中的 DataSource 参数
        factory.addConstructorArgValue(parseDataSources(element));
//解析构造函数中 ShardingRuleConfiguration 参数        factory.addConstructorArgValue(parseShardingRuleConfiguration(element));
       //解析构造函数中 Properties 参数
        factory.addConstructorArgValue(parseProperties(element, parserContext));
        factory.setDestroyMethodName("close");
        return factory.getBeanDefinition();
}

private Map<String, RuntimeBeanReference> parseDataSources(final Element element) {
        Element shardingRuleElement = DomUtils.getChildElementByTagName(element, ShardingDataSourceBeanDefinitionParserTag.SHARDING_RULE_CONFIG_TAG);
        List<String> dataSources = Splitter.on(",").trimResults().splitToList(shardingRuleElement.getAttribute(ShardingDataSourceBeanDefinitionParserTag.DATA_SOURCE_NAMES_TAG));
        Map<String, RuntimeBeanReference> result = new ManagedMap<>(dataSources.size());
        for (String each : dataSources) {
            result.put(each, new RuntimeBeanReference(each));
        }
        return result;
}

http\://shardingsphere.apache.org/schema/shardingsphere/sharding/sharding.xsd=META-INF/namespace/sharding.xsd
http\://shardingsphere.apache.org/schema/shardingsphere/masterslave/master-slave.xsd=META-INF/namespace/master-slave.xsd
http\://shardingsphere.apache.org/schema/shardingsphere/encrypt/encrypt.xsd=META-INF/namespace/encrypt.xsd

http\://shardingsphere.apache.org/schema/shardingsphere/sharding=org.apache.shardingsphere.shardingjdbc.spring.namespace.handler.ShardingNamespaceHandler
http\://shardingsphere.apache.org/schema/shardingsphere/masterslave=org.apache.shardingsphere.shardingjdbc.spring.namespace.handler.MasterSlaveNamespaceHandler
http\://shardingsphere.apache.org/schema/shardingsphere/encrypt=org.apache.shardingsphere.shardingjdbc.spring.namespace.handler.EncryptNamespaceHandler

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.apache.shardingsphere.shardingjdbc.spring.boot.SpringBootConfiguration

@Configuration
@ComponentScan("org.apache.shardingsphere.spring.boot.converter")
@EnableConfigurationProperties({
        SpringBootShardingRuleConfigurationProperties.class, 
        SpringBootMasterSlaveRuleConfigurationProperties.class, SpringBootEncryptRuleConfigurationProperties.class, SpringBootPropertiesConfigurationProperties.class})
@ConditionalOnProperty(prefix = "spring.shardingsphere", name = "enabled", havingValue = "true", matchIfMissing = true)
@AutoConfigureBefore(DataSourceAutoConfiguration.class)
@RequiredArgsConstructor
public class SpringBootConfiguration implements EnvironmentAware

@ConfigurationProperties(prefix = "spring.shardingsphere.sharding")
public class SpringBootShardingRuleConfigurationProperties extends YamlShardingRuleConfiguration {
}

@Bean
@Conditional(ShardingRuleCondition.class)
public DataSource shardingDataSource() throws SQLException {
        return ShardingDataSourceFactory.createDataSource(dataSourceMap, new ShardingRuleConfigurationYamlSwapper().swap(shardingRule), props.getProps());
}

public final class ShardingRuleCondition extends SpringBootCondition {

    @Override
    public ConditionOutcome getMatchOutcome(final ConditionContext conditionContext, final AnnotatedTypeMetadata annotatedTypeMetadata) {
        boolean isMasterSlaveRule = new MasterSlaveRuleCondition().getMatchOutcome(conditionContext, annotatedTypeMetadata).isMatch();
        boolean isEncryptRule = new EncryptRuleCondition().getMatchOutcome(conditionContext, annotatedTypeMetadata).isMatch();
        return isMasterSlaveRule || isEncryptRule ? ConditionOutcome.noMatch("Have found master-slave or encrypt rule in environment") : ConditionOutcome.match();
    }
}

@Override
public final void setEnvironment(final Environment environment) {
        String prefix = "spring.shardingsphere.datasource.";
        for (String each : getDataSourceNames(environment, prefix)) {
            try {
                dataSourceMap.put(each, getDataSource(environment, prefix, each));
            } catch (final ReflectiveOperationException ex) {
                throw new ShardingException("Can't find datasource type!", ex);
            } catch (final NamingException namingEx) {
                throw new ShardingException("Can't find JNDI datasource!", namingEx);
            }
        }
}

spring.shardingsphere.datasource.names=ds0,ds1

spring.shardingsphere.datasource.ds0.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds0.url=jdbc:mysql://localhost/ds0
spring.shardingsphere.datasource.ds0.username=root
spring.shardingsphere.datasource.ds0.password=root

spring.shardingsphere.datasource.ds1.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds1.url=jdbc:mysql://localhost/ds1
spring.shardingsphere.datasource.ds1.username=root
spring.shardingsphere.datasource.ds1.password=root

import org.apache.shardingsphere.driver.api.yaml.YamlShardingSphereDataSourceFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;
import java.io.File;

@SpringBootApplication
@EnableTransactionManagement
public class SpringBootConfiguration {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootConfiguration.class, args);
    }

    @Bean
    public DataSource dataSource() throws Exception {
        // 假设有一个 sharding 配置文件 sharding-databases-tables.yaml
        return YamlShardingSphereDataSourceFactory.createDataSource(new File("path/to/sharding-databases-tables.yaml"));
    }
}