学习sharding-jdbc 分库分表扩展框架

先丢代码地址

https://gitee.com/a247292980/sharding-jdbc

再丢pom.xml的dependency

 <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring.version>3.2.5.RELEASE</spring.version>
        <mybatis.version>3.2.4</mybatis.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
        <dependency>
            <groupId>com.dangdang</groupId>
            <artifactId>sharding-jdbc-core</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.28</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.5</version>
        </dependency>
    </dependencies>

最后丢代码结构图

我讲shardingJdbc.java这个文件的东西，留意好我的注释

public class ShardingJdbc {
    /**
     * main方法
     */
    public static void main(String[] args) {
//       设置数据源，不分库的话，只设置一个
        Map<String, DataSource> dataSourceMap = new HashMap<String, DataSource>(2);
        dataSourceMap.put("sharding_0", createDataSource("sharding_0"));
        dataSourceMap.put("sharding_1", createDataSource("sharding_1"));

        DataSourceRule dataSourceRule = new DataSourceRule(dataSourceMap);

        //分表分库的表，第一个参数是逻辑表名，第二个是实际表名，第三个是实际库
        TableRule orderTableRule = new TableRule("t_order", Arrays.asList("t_order_0", "t_order_1"), dataSourceRule);
        TableRule orderItemTableRule = new TableRule("t_order_item", Arrays.asList("t_order_item_0", "t_order_item_1"), dataSourceRule);

        /**
         * DatabaseShardingStrategy 分库策略
         * 参数一：根据哪个字段分库
         * 参数二：分库路由函数
         *
         * TableShardingStrategy 分表策略
         * 参数一：根据哪个字段分表
         * 参数二：分表路由函数
         *
         * user_id选择哪个库
         * order_id选择那个表
         *
         * ModuloDataBaseShardingAlgorithm
         * ModuloTableShardingAlgorithm
         * 被2整除是0，反之是1
         *
         */

        ShardingRule shardingRule = new ShardingRule(dataSourceRule, Arrays.asList(orderTableRule, orderItemTableRule)
                , Arrays.asList(new BindingTableRule(Arrays.asList(orderTableRule, orderItemTableRule)))
                , new DatabaseShardingStrategy("user_id", new ModuloDataBaseShardingAlgorithm())
                , new TableShardingStrategy("order_id", new ModuloTableShardingAlgorithm()));

        DataSource dataSource = new ShardingDataSource(shardingRule);
        String sql =
                "SELECT i.* FROM t_order o JOIN t_order_item i " +
                        "ON o.order_id=i.order_id " +
                        "WHERE o.user_id= ? AND o.order_id = ?";
        try {
            Connection connection = dataSource.getConnection();
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

//            preparedStatement.setInt(1, 10);
//            preparedStatement.setInt(2, 1001);

//             先根据分库规则去了sharding_1
            preparedStatement.setInt(1, 11);
//            再根据分表规则去了t_order_0,t_order_item_0
            preparedStatement.setInt(2, 1000);

            ResultSet result = preparedStatement.executeQuery();
            while (result.next()) {
                System.out.println("1--------" + result.getInt(1));
                System.out.println("2--------" + result.getInt(2));
                System.out.println("3--------" + result.getInt(3));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * @param dataSourceName
     * @return dataSource
     * @DESCRIPTION 创建数据源
     */
    private static DataSource createDataSource(String dataSourceName) {
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl(String.format("jdbc:mysql://localhost:3306/%s", dataSourceName));
        dataSource.setUsername("root");
        dataSource.setPassword("123456789");
        return dataSource;
    }
}

 另两个放的是具体分库逻辑，很简单，有兴趣的下源码跑一下即可