sharding-jdbc配置分析Configuration

public final class ShardingMasterSlaveConfigurationPrecise implements ExampleConfiguration {
    
    @Override
    public DataSource getDataSource() throws SQLException {
        ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
        //分片表规则配置
        shardingRuleConfig.getTableRuleConfigs().add(getOrderTableRuleConfiguration());
        shardingRuleConfig.getTableRuleConfigs().add(getOrderItemTableRuleConfiguration());
        shardingRuleConfig.getBindingTableGroups().add("t_order, t_order_item");
        //设置默认数据源分片策略
        shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(new StandardShardingStrategyConfiguration("user_id", new PreciseModuloShardingDatabaseAlgorithm()));
        //设置默认表分片策略
        shardingRuleConfig.setDefaultTableShardingStrategyConfig(new StandardShardingStrategyConfiguration("order_id", new PreciseModuloShardingTableAlgorithm()));
        //主从配置，支持多主多从
        shardingRuleConfig.setMasterSlaveRuleConfigs(getMasterSlaveRuleConfigurations());
        //创建ShardingDataSource数据源
        return ShardingDataSourceFactory.createDataSource(createDataSourceMap(), shardingRuleConfig, new Properties());
    }
    
    private static TableRuleConfiguration getOrderTableRuleConfiguration() {
        //分片表配置
        TableRuleConfiguration result = new TableRuleConfiguration(/*逻辑表*/"t_order", /*数据源名.真实表*/"ds_${0..1}.t_order_${[0, 1]}");
        //自定义主键生成配置
        result.setKeyGeneratorConfig(new KeyGeneratorConfiguration("SNOWFLAKE", "order_id", getProperties()));
        return result;
    }
    
    private static TableRuleConfiguration getOrderItemTableRuleConfiguration() {
        TableRuleConfiguration result = new TableRuleConfiguration("t_order_item", "ds_${0..1}.t_order_item_${[0, 1]}");
        result.setKeyGeneratorConfig(new KeyGeneratorConfiguration("SNOWFLAKE", "order_item_id", getProperties()));
        return result;
    }
    
    private static List<MasterSlaveRuleConfiguration> getMasterSlaveRuleConfigurations() {
        MasterSlaveRuleConfiguration masterSlaveRuleConfig1 = new MasterSlaveRuleConfiguration("ds_0", "demo_ds_master_0", Arrays.asList("demo_ds_master_0_slave_0", "demo_ds_master_0_slave_1"));
        MasterSlaveRuleConfiguration masterSlaveRuleConfig2 = new MasterSlaveRuleConfiguration("ds_1", "demo_ds_master_1", Arrays.asList("demo_ds_master_1_slave_0", "demo_ds_master_1_slave_1"));
        return Lists.newArrayList(masterSlaveRuleConfig1, masterSlaveRuleConfig2);
    }
    
    private static Map<String, DataSource> createDataSourceMap() {
        final Map<String, DataSource> result = new HashMap<>();
        result.put("demo_ds_master_0", DataSourceUtil.createDataSource("demo_ds_master_0"));
        result.put("demo_ds_master_0_slave_0", DataSourceUtil.createDataSource("demo_ds_master_0_slave_0"));
        result.put("demo_ds_master_0_slave_1", DataSourceUtil.createDataSource("demo_ds_master_0_slave_1"));
        result.put("demo_ds_master_1", DataSourceUtil.createDataSource("demo_ds_master_1"));
        result.put("demo_ds_master_1_slave_0", DataSourceUtil.createDataSource("demo_ds_master_1_slave_0"));
        result.put("demo_ds_master_1_slave_1", DataSourceUtil.createDataSource("demo_ds_master_1_slave_1"));
        return result;
    }
    
    private static Properties getProperties() {
        Properties result = new Properties();
        result.setProperty("worker.id", "123");
        return result;
    }
}

@Getter
@Setter
public final class ShardingRuleConfiguration implements RuleConfiguration {
    //表规则配置
    private Collection<TableRuleConfiguration> tableRuleConfigs = new LinkedList<>();


    //绑定表配置
    private Collection<String> bindingTableGroups = new LinkedList<>();


    //广播表配置
    private Collection<String> broadcastTables = new LinkedList<>();


    //默认数据源名称
    private String defaultDataSourceName;


    //默认分库策略
    private ShardingStrategyConfiguration defaultDatabaseShardingStrategyConfig;


    //默认分片策略
    private ShardingStrategyConfiguration defaultTableShardingStrategyConfig;


    //默认主键生成工具类
    private KeyGeneratorConfiguration defaultKeyGeneratorConfig;


    //主从规则配置
    private Collection<MasterSlaveRuleConfiguration> masterSlaveRuleConfigs = new LinkedList<>();


    //数据脱敏规则配置
    private EncryptRuleConfiguration encryptRuleConfig;
}

/**
 * Sharding data source factory.
 *
 * @author zhangliang
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class ShardingDataSourceFactory {
    
    /**
     * Create sharding data source.
     *
     * @param dataSourceMap data source map
     * @param shardingRuleConfig rule configuration for databases and tables sharding
     * @param props properties for data source
     * @return sharding data source
     * @throws SQLException SQL exception
     */
    public static DataSource createDataSource(
            final Map<String, DataSource> dataSourceMap, final ShardingRuleConfiguration shardingRuleConfig, final Properties props) throws SQLException {
        //创建ShardingDataSource数据源，同时创建sharding rule配置
        return new ShardingDataSource(dataSourceMap, new ShardingRule(shardingRuleConfig, dataSourceMap.keySet()), props);
    }
}

public ShardingRule(final ShardingRuleConfiguration shardingRuleConfig, final Collection<String> dataSourceNames) {
        Preconditions.checkArgument(null != shardingRuleConfig, "ShardingRuleConfig cannot be null.");
        Preconditions.checkArgument(null != dataSourceNames && !dataSourceNames.isEmpty(), "Data sources cannot be empty.");
        this.shardingRuleConfig = shardingRuleConfig;
        //sharding数据源名称
        shardingDataSourceNames = new ShardingDataSourceNames(shardingRuleConfig, dataSourceNames);
        //创建表规则集合
        tableRules = createTableRules(shardingRuleConfig);
        //创建分组绑定表
        //1.从tableRules查找
        //2.是否广播表，如果是广播表，dataSourceNames.size() == 1 ? dataSourceNames.iterator().next() : shardingRuleConfig.getDefaultDataSourceName();
        //3.已上两种情况都不满足，则使用默认数据源创建tableRule
        bindingTableRules = createBindingTableRules(shardingRuleConfig.getBindingTableGroups());
        //广播表
        broadcastTables = shardingRuleConfig.getBroadcastTables();
        //默认分库策略
        defaultDatabaseShardingStrategy = createDefaultShardingStrategy(shardingRuleConfig.getDefaultDatabaseShardingStrategyConfig());
        //默认表分片策略
        defaultTableShardingStrategy = createDefaultShardingStrategy(shardingRuleConfig.getDefaultTableShardingStrategyConfig());
        //默认主键生成工具类
        defaultShardingKeyGenerator = createDefaultKeyGenerator(shardingRuleConfig.getDefaultKeyGeneratorConfig());
        //创建主从规则
        masterSlaveRules = createMasterSlaveRules(shardingRuleConfig.getMasterSlaveRuleConfigs());
        //数据脱敏规则
        encryptRule = createEncryptRule(shardingRuleConfig.getEncryptRuleConfig());
    }

public TableRule(final TableRuleConfiguration tableRuleConfig, final ShardingDataSourceNames shardingDataSourceNames, final String defaultGenerateKeyColumn) {
        //获取逻辑表
        logicTable = tableRuleConfig.getLogicTable().toLowerCase();
        //inline表达式解析出真实表，比如：ds_${0..1}.t_order_${[0, 1]}
        //解析出来为：
        //ds_0.t_order_0
        //ds_0.t_order_1
        //ds_1.t_order_0
        //ds_1.t_order_1
        List<String> dataNodes = new InlineExpressionParser(tableRuleConfig.getActualDataNodes()).splitAndEvaluate();


        dataNodeIndexMap = new HashMap<>(dataNodes.size(), 1);


        //真实表数据节点
        //1.如果没有配置真实表，则根据逻辑表、数据源来生成对应真实表数据节点
        //2.否则根据inline表达式解析出来的真实表来生成真实数据节点
        actualDataNodes = isEmptyDataNodes(dataNodes)
            ? generateDataNodes(tableRuleConfig.getLogicTable(), shardingDataSourceNames.getDataSourceNames()) : generateDataNodes(dataNodes, shardingDataSourceNames.getDataSourceNames());
        //真实表
        actualTables = getActualTables();
        //数据源->分片策略
        databaseShardingStrategy = null == tableRuleConfig.getDatabaseShardingStrategyConfig() ? null : ShardingStrategyFactory.newInstance(tableRuleConfig.getDatabaseShardingStrategyConfig());
        //表->分片策略
        tableShardingStrategy = null == tableRuleConfig.getTableShardingStrategyConfig() ? null : ShardingStrategyFactory.newInstance(tableRuleConfig.getTableShardingStrategyConfig());
        //主键字段
        generateKeyColumn = getGenerateKeyColumn(tableRuleConfig.getKeyGeneratorConfig(), defaultGenerateKeyColumn);
        //生成主键工具类，比如SNOWFLAKE
        shardingKeyGenerator = containsKeyGeneratorConfiguration(tableRuleConfig)
                ? new ShardingKeyGeneratorServiceLoader().newService(tableRuleConfig.getKeyGeneratorConfig().getType(), tableRuleConfig.getKeyGeneratorConfig().getProperties()) : null;
    }