ShardingJDBC案例实战

基础分库

以下实例基于shardingsphere 4.1.0 + SpringBoot 2.2.5.RELEASE版本

依赖导入：

<properties>    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>    <project.compile.sourceEncoding>UTF-8</project.compile.sourceEncoding>    <springboot.version>2.2.5.RELEASE</springboot.version>    <shardingsphere.version>4.1.0</shardingsphere.version></properties>    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-jdbc</artifactId>            <version>${springboot.version}</version>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-jpa</artifactId>            <version>${springboot.version}</version>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <version>${springboot.version}</version>            <scope>test</scope>        </dependency>        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>            <version>8.0.13</version>        </dependency>        <dependency>            <groupId>org.apache.shardingsphere</groupId>            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>            <version>${shardingsphere.version}</version>        </dependency>    </dependencies>

场景：通过id字段取余分片到两个数据库

1. 引入依赖

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

2. 参数配置

spring.shardingsphere.datasource.names=ds0,ds1spring.shardingsphere.datasource.ds0.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.ds0.jdbc-url=jdbc:mysql://localhost:3306/ds_0?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.ds0.username=rootspring.shardingsphere.datasource.ds0.password=0490218292spring.shardingsphere.datasource.ds1.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.ds1.jdbc-url=jdbc:mysql://localhost:3306/ds_1?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.ds1.username=rootspring.shardingsphere.datasource.ds1.password=0490218292spring.shardingsphere.sharding.tables.position.database-strategy.inline.sharding-column=idspring.shardingsphere.sharding.tables.position.database-strategy.inline.algorithm-expression=ds$->{id % 2}

3. 测试插入数据

@Test    public void testAdd(){        for (int i = 0; i <= 20; i++) {            Position position=new Position();            position.setId((long) i);            position.setName("lagou"+i);            position.setSalary("1000");            position.setCity("beijing");            positionRepository.save(position);        }    }

主键生成使用雪花算法

1. id需要设置IDENTITY

@Id@Column(name = "id")@GeneratedValue(strategy = GenerationType.IDENTITY)private Long id;

2. 参数配置

增加id设置：

#id设置spring.shardingsphere.sharding.tables.position.key-generator.column=idspring.shardingsphere.sharding.tables.position.key-generator.type=SNOWFLAKE

3. 测试

    @Test    public void testAdd(){        for (int i = 0; i <= 20; i++) {            Position position=new Position();            position.setName("lagou"+i);            position.setSalary("1000");            position.setCity("beijing");            positionRepository.save(position);        }    }

自定义主键生成器

1. 自定义主键生成器类

public class MyCustomId implements ShardingKeyGenerator {    @Override    public Comparable<?> generateKey() {        return System.currentTimeMillis()+new Random().nextInt(100000);    }    @Override    public String getType() {        //自定义一个名称        return "MYID";    }    @Override    public Properties getProperties() {        return null;    }    @Override    public void setProperties(Properties properties) {    }}

2. 配置

在resources下创建META-INF/services目录，并创建一个文件，文件名为：org.apache.shardingsphere.spi.keygen.ShardingKeyGenerator

里面写自定义主键生成器的全类名

3. 配置生成器类型的地方改为和我们自定义的生成器的类型一致

#id设置spring.shardingsphere.sharding.tables.position.key-generator.column=idspring.shardingsphere.sharding.tables.position.key-generator.type=MYID

两表关联的分库

场景：职位表（position）和职位详情表（position_detail）是关联的两个表，关联关系是：position_detail.pid = position.id，那么我们期望在插入数据后，根据职位Id进行查询时能够只查询一个库，而不是笛卡尔积的进行查询。

1. 完整的参数配置

spring.shardingsphere.datasource.names=ds0,ds1spring.shardingsphere.datasource.ds0.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.ds0.jdbc-url=jdbc:mysql://localhost:3306/ds_0?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.ds0.username=rootspring.shardingsphere.datasource.ds0.password=0490218292spring.shardingsphere.datasource.ds1.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.ds1.jdbc-url=jdbc:mysql://localhost:3306/ds_1?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.ds1.username=rootspring.shardingsphere.datasource.ds1.password=0490218292#职位表设置spring.shardingsphere.sharding.tables.position.database-strategy.inline.sharding-column=idspring.shardingsphere.sharding.tables.position.database-strategy.inline.algorithm-expression=ds$->{id % 2}#id设置spring.shardingsphere.sharding.tables.position.key-generator.column=idspring.shardingsphere.sharding.tables.position.key-generator.type=SNOWFLAKE#职位表详情设置spring.shardingsphere.sharding.tables.position_detail.database-strategy.inline.sharding-column=pidspring.shardingsphere.sharding.tables.position_detail.database-strategy.inline.algorithm-expression=ds$->{pid % 2}#id设置spring.shardingsphere.sharding.tables.position_detail.key-generator.column=idspring.shardingsphere.sharding.tables.position_detail.key-generator.type=SNOWFLAKE

可以看出position的id的分片策略和position_detail的pid的分片策略一致。
2. 测试

@Testpublic void testQueryPosition(){    Object positionAndDetailById = positionRepository.findPositionAndDetailById(730545854473043968L);    System.out.println(positionAndDetailById);}

可以看出，只查询了一个库：

广播表设置

场景：城市表属于基础表，数据量不大，每个库都可以存一样的数据。

1. 广播表配置

#广播表设置spring.shardingsphere.sharding.broadcast-tables=cityspring.shardingsphere.sharding.tables.city.key-generator.column=idspring.shardingsphere.sharding.tables.city.key-generator.type=SNOWFLAKE

2. 测试

@Testpublic void testAddCity(){    City city=new City();    city.setName("成都");    city.setProvince("四川");    cityRepository.save(city);}

和之前的不同，这一条数据的插入，两个库都有。且ID也是一致的。

分库且分表

场景：我们有一个订单表，可以根据公司id(companyId)进行分库，然后在根据id进行分表。

1. 参数配置

#订单表分库且分表spring.shardingsphere.sharding.tables.b_order.database-strategy.inline.sharding-column=company_idspring.shardingsphere.sharding.tables.b_order.database-strategy.inline.algorithm-expression=ds$->{company_id%2}spring.shardingsphere.sharding.tables.b_order.table-strategy.inline.sharding-column=idspring.shardingsphere.sharding.tables.b_order.table-strategy.inline.algorithm-expression=b_order${id % 2}spring.shardingsphere.sharding.tables.b_order.actual-data-nodes=ds${0..1}.b_order${0..1}#id设置spring.shardingsphere.sharding.tables.b_order.key-generator.column=idspring.shardingsphere.sharding.tables.b_order.key-generator.type=SNOWFLAKE

2. 测试

    @Test    @Repeat(100)    public void testAddBOrder(){        BOrder bOrder=new BOrder();        bOrder.setDel(false);        bOrder.setCompanyId(new Random().nextInt(10));        bOrder.setPositionId(23);        bOrder.setUserId(22);        bOrder.setPublishUserId(11);        bOrder.setResumeType(1);        bOrder.setStatus("AUTO");        bOrder.setCreateTime(new Date());        bOrder.setOperateTime(new Date());        bOrder.setWorkYear("2");        bOrder.setName("lagou");        bOrder.setPositionName("Java");        bOrder.setResumeId(23443);        bOrderRepository.save(bOrder);    }

我们发现数据插入到了ds_0.b_order0、ds_0.b_order1、ds_1.b_order0、ds_1.b_order1四个node里面。

读写分离

1. 参数配置

spring.shardingsphere.datasource.names=master,slave0spring.shardingsphere.datasource.master.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.master.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.master.jdbc-url=jdbc:mysql://localhost:3306/ds_0?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.master.username=rootspring.shardingsphere.datasource.master.password=0490218292spring.shardingsphere.datasource.slave0.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.slave0.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.slave0.jdbc-url=jdbc:mysql://localhost:3306/ds_0_slave?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTCspring.shardingsphere.datasource.slave0.username=rootspring.shardingsphere.datasource.slave0.password=0490218292#读写分离spring.shardingsphere.masterslave.name=datasourcespring.shardingsphere.masterslave.master-data-source-name=masterspring.shardingsphere.masterslave.slave-data-source-names=slave0#多个读库时的负载均衡策略spring.shardingsphere.masterslave.load-balance-algorithm-type=ROUND_ROBIN

2. 查询测试

    @Test    public void test(){        List<City> all = cityRepository.findAll();        all.forEach(x->System.out.println(x));    }

分库分表+读写分离的参数配置

#数据源spring.shardingsphere.datasource.names=master0,slave0,slave1,master1,slave2,slave3spring.shardingsphere.datasource.master0.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.master0.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.master0.jdbc-url=jdbc:mysql://localhost:3306/master0?useUnicode=true&characterEncoding=utf-8&useSSL=falsespring.shardingsphere.datasource.master0.username=rootspring.shardingsphere.datasource.master0.password=rootspring.shardingsphere.datasource.slave0.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.slave0.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.slave0.jdbc-url=jdbc:mysql://localhost:3306/slave0?useSSL=falsespring.shardingsphere.datasource.slave0.username=rootspring.shardingsphere.datasource.slave0.password=rootspring.shardingsphere.datasource.slave1.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.slave1.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.slave1.jdbc-url=jdbc:mysql://localhost:3306/slave1?useSSL=falsespring.shardingsphere.datasource.slave1.username=rootspring.shardingsphere.datasource.slave1.password=rootspring.shardingsphere.datasource.master1.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.master1.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.master1.jdbc-url=jdbc:mysql://localhost:3306/master1?useUnicode=true&characterEncoding=utf-8&useSSL=falsespring.shardingsphere.datasource.master1.username=rootspring.shardingsphere.datasource.master1.password=rootspring.shardingsphere.datasource.slave2.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.slave2.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.slave2.jdbc-url=jdbc:mysql://localhost:3306/slave2?useSSL=falsespring.shardingsphere.datasource.slave2.username=rootspring.shardingsphere.datasource.slave2.password=rootspring.shardingsphere.datasource.slave3.type=com.zaxxer.hikari.HikariDataSourcespring.shardingsphere.datasource.slave3.driver-class-name=com.mysql.jdbc.Driverspring.shardingsphere.datasource.slave3.jdbc-url=jdbc:mysql://localhost:3306/slave3?useSSL=falsespring.shardingsphere.datasource.slave3.username=rootspring.shardingsphere.datasource.slave3.password=root#分库分表spring.shardingsphere.sharding.tables.b_order.database-strategy.inline.sharding-column=company_idspring.shardingsphere.sharding.tables.b_order.database-strategy.inline.algorithm-expression=master$->{company_id % 2}spring.shardingsphere.sharding.tables.b_order.actual-data-nodes=master$->{0..1}.b_order$->{0..1}spring.shardingsphere.sharding.tables.b_order.table-strategy.inline.sharding-column=idspring.shardingsphere.sharding.tables.b_order.table-strategy.inline.algorithm-expression=b_order$->{id % 2}#读写分离spring.shardingsphere.sharding.master-slave-rules.master0.master-data-source-name=master0spring.shardingsphere.sharding.master-slave-rules.master0.slave-data-source-names=slave0, slave1spring.shardingsphere.sharding.master-slave-rules.master1.master-data-source-name=master1spring.shardingsphere.sharding.master-slave-rules.master1.slave-data-source-names=slave2, slave3

强制路由

在一些应用场景中，分片条件并不存在于SQL，而存在于外部业务逻辑。因此需要提供一种通过在外部业务代码中指定路由配置的一种方式，在ShardingSphere中叫做Hint。如果使用Hint指定了强制分片路由，那么SQL将会无视原有的分片逻辑，直接路由至指定的数据节点操作。

使用场景：

• 数据分片操作，如果分片键没有在SQL或者数据表中，而是在业务逻辑代码中
• 读写分离操作，如果需要强制在主库进行某些操作

1. 自定义Hint实现类

public class MyHintShardingAlgorithm implements HintShardingAlgorithm<String> {    @Override    public Collection<String> doSharding(Collection<String> collection, HintShardingValue<String> hintShardingValue) {        Collection<String> result=new ArrayList<>();       if(hintShardingValue.getValues().contains("master")){           ((ArrayList<String>) result).add("master");       }else {           ((ArrayList<String>) result).add("slave0");       }       return result;    }}

2. 配置自定义的Hint类

spring.shardingsphere.sharding.tables.city.database-strategy.hint.algorithm-class-name=com.mmc.sharding.hint.MyHintShardingAlgorithm

3. 测试

    @Test    public void testHint(){        HintManager hintManager = HintManager.getInstance();        hintManager.addDatabaseShardingValue("city","master");//        hintManager.setMasterRouteOnly();        List<City> all = cityRepository.findAll();        all.forEach(x->System.out.println(x));    }

还可以使用hintManager.setMasterRouteOnly()指定仅路由到主库。

测试过程中发现Hint的自定义策略和读写分离配置有冲突。配置了读写分离后自定义Hint类不生效了，仅hintManager.setMasterRouteOnly()还可以用。

数据加密

脱敏配置分为如下几个：数据源配置，加密器配置，脱敏表配置以及查询属性配置，其详情如下图所示：

• 数据源配置：指Datasource的配置信息
• 加密器配置：指使用什么加密策略进行加解密。目前ShardingSphere内置了两种加解密策略AES、MD5
• 脱敏表配置：指定哪个列用于存储密文数据，哪个列存明文数据，以及在应用里用哪个列（应用层sql里使用的列名）
• 查询属性配置：当数据库同时存了明文和密文的时候，该属性开关用于决定是直接查询数据库表里的明文，还是查密文然后通过解密后返回。

1. 先创建个表

CREATE TABLE `c_user` (  `Id` bigint(11) NOT NULL AUTO_INCREMENT,  `name` varchar(256) DEFAULT NULL,  `pwd_plain` varchar(256) DEFAULT NULL,  `pwd_cipher` varchar(256) DEFAULT NULL,  PRIMARY KEY (`Id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

2. 创建实体类

@Entity@Table(name = "c_user")public class CUser implements Serializable {    @Id    @Column(name = "id")    @GeneratedValue(strategy = GenerationType.IDENTITY)    private Long id;    @Column(name = "name")    private String name;    /**     * 逻辑列名     */    @Column(name = "password")    private String password;}

3. 参数配置

#定义数据表真实明文列#spring.shardingsphere.encrypt.tables.c_user.columns.password.plain-column=pwd_plain#定义数据表真实密文列spring.shardingsphere.encrypt.tables.c_user.columns.password.cipher-column=pwd_cipher#定义加密器，名称为lagou_pwdspring.shardingsphere.encrypt.encryptors.lagou_pwd.type=aesspring.shardingsphere.encrypt.encryptors.lagou_pwd.props.aes.key.value=1234#指定加密器，password是逻辑列名，与实体类中的字段对应spring.shardingsphere.encrypt.tables.c_user.columns.password.encryptor=lagou_pwd

4. 测试

    @Test    public void testEncrypt(){        CUser cUser=new CUser();        cUser.setName("阿百川");        cUser.setPassword("123456");        cUserRepository.save(cUser);    }    @Test    public void testQueryByPassword(){        List<CUser> byPassword = cUserRepository.findByPassword("123456");        System.out.println(byPassword);    }

数据库存放的已经是密文了，通过明文密码也可以查询到数据了。

分布式事务

仅仅需要在测试方法上加上两个注解：

    @Transactional(rollbackFor = Exception.class)    @ShardingTransactionType(TransactionType.XA)

TransactionType有XA、BASE、LOCAL三种

@Test    @Transactional(rollbackFor = Exception.class)    @ShardingTransactionType(TransactionType.XA)    public void testAddDetail(){        for (int i = 0; i <= 3; i++) {            Position position=new Position();            position.setName("lagou"+i);            position.setSalary("1000");            position.setCity("beijing");            positionRepository.save(position);            if(i==3){                throw new RuntimeException();            }            PositionDetail positionDetail=new PositionDetail();            positionDetail.setPid(position.getId());            positionDetail.setDescription("详情");            positionDetailRepository.save(positionDetail);        }    }