1.什么是sharding-jdbc?
目前新版已经更名为ShardingSphere-JDBC ,ShardingSphere-JDBC 定位为轻量级 Java 框架,在 Java 的 JDBC 层提供的额外服务。 它使用客户端直连数据库,以 jar 包形式提供服务,无需额外部署和依赖,可理解为增强版的 JDBC 驱动,完全兼容 JDBC 和各种 ORM 框架。
- 适用于任何基于 JDBC 的 ORM 框架,如:JPA, Hibernate, Mybatis, Spring JDBC Template 或直接使用 JDBC;
- 支持任何第三方的数据库连接池,如:DBCP, C3P0, BoneCP, HikariCP 等;
- 支持任意实现 JDBC 规范的数据库,目前支持 MySQL,PostgreSQL,Oracle,SQLServer 以及任何可使用 JDBC 访问的数据库。
2.原理
Apache ShardingSphere-JDBC 可以通过 Java
和 YAML
这 2 种方式进行配置,开发者可根据场景选择适合的配置方式。
3.代码工程
实验目的:实现分库分表规则
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.1.5</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>sharding-jdbc</artifactId>
<version>0.1-SNAPSHOT</version>
<properties>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
<shardingsphere.version>5.3.2</shardingsphere.version>
<mysql.version>8.2.0</mysql.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
<dependency>
<groupId>com.mysql</groupId>
<artifactId>mysql-connector-j</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>shardingsphere-jdbc-core</artifactId>
<version>${shardingsphere.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>junit-jupiter</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>mysql</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>testcontainers-bom</artifactId>
<version>1.18.3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
</project>
service
package com.et.sharding.jdbc;
import org.springframework.stereotype.Service;
@Service
public class OrderService {
private final OrderRepository orderRepository;
public OrderService(OrderRepository orderRepository) {
this.orderRepository = orderRepository;
}
public Order createOrder(Order order) {
return orderRepository.save(order);
}
public Order getOrder(Long id) {
return orderRepository.findById(id)
.orElseThrow(() -> new IllegalArgumentException("Order not found"));
}
}
reponsitory
继承最基本的crud操作类
package com.et.sharding.jdbc;
import org.springframework.data.jpa.repository.JpaRepository;
public interface OrderRepository extends JpaRepository<Order, Long> { }
application.yml
spring:
datasource:
driver-class-name: org.apache.shardingsphere.driver.ShardingSphereDriver
url: jdbc:shardingsphere:classpath:sharding.yml
jpa:
properties:
hibernate:
dialect: org.hibernate.dialect.MySQL8Dialect
hibernate:
ddl-auto: create-drop
sharding.yml
这里采用yml方式配置分库分表规则
dataSources:
ds0:
dataSourceClassName: com.zaxxer.hikari.HikariDataSource
driverClassName: com.mysql.jdbc.Driver
jdbcUrl: jdbc:mysql://localhost:13306/ds0?serverTimezone=UTC&useSSL=false&useUnicode=true&characterEncoding=UTF-8
username: test
password: test
ds1:
dataSourceClassName: com.zaxxer.hikari.HikariDataSource
driverClassName: com.mysql.jdbc.Driver
jdbcUrl: jdbc:mysql://localhost:13307/ds1?serverTimezone=UTC&useSSL=false&useUnicode=true&characterEncoding=UTF-8
username: test
password: test
rules:
- !SHARDING
tables:
order:
actualDataNodes: ds${0..1}.order
defaultDatabaseStrategy:
standard:
shardingColumn: order_id
shardingAlgorithmName: database_inline
defaultTableStrategy:
none:
shardingAlgorithms:
database_inline:
type: INLINE
props:
algorithm-expression: ds${order_id % 2}
props:
sql-show: false
entity
配置字段名,jpa会根据规则
registry.add("spring.jpa.hibernate.ddl-auto", () -> "create-drop");
自动生成数据表
package com.et.sharding.jdbc;
import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.EnumType;
import jakarta.persistence.Enumerated;
import jakarta.persistence.Id;
import jakarta.persistence.Table;
import java.math.BigDecimal;
import java.time.LocalDate;
import java.util.Objects;
@Entity
@Table(name = "`order`")
public class Order {
@Id
@Column(name = "order_id")
private Long orderId;
@Column(name = "customer_id")
private Long customerId;
@Column(name = "total_price")
private BigDecimal totalPrice;
@Enumerated(EnumType.STRING)
@Column(name = "order_status")
private Status orderStatus;
@Column(name = "order_date")
private LocalDate orderDate;
@Column(name = "delivery_address")
private String deliveryAddress;
public Long getOrderId() {
return orderId;
}
public void setOrderId(Long orderId) {
this.orderId = orderId;
}
public Long getCustomerId() {
return customerId;
}
public void setCustomerId(Long customerId) {
this.customerId = customerId;
}
public BigDecimal getTotalPrice() {
return totalPrice;
}
public void setTotalPrice(BigDecimal totalPrice) {
this.totalPrice = totalPrice;
}
public Status getOrderStatus() {
return orderStatus;
}
public void setOrderStatus(Status orderStatus) {
this.orderStatus = orderStatus;
}
public LocalDate getOrderDate() {
return orderDate;
}
public void setOrderDate(LocalDate orderDate) {
this.orderDate = orderDate;
}
public String getDeliveryAddress() {
return deliveryAddress;
}
public void setDeliveryAddress(String deliveryAddress) {
this.deliveryAddress = deliveryAddress;
}
protected Order() {}
public Order(Long orderId, Long customerId, BigDecimal totalPrice, Status orderStatus, LocalDate orderDate, String deliveryAddress) {
this.orderId = orderId;
this.customerId = customerId;
this.totalPrice = totalPrice;
this.orderStatus = orderStatus;
this.orderDate = orderDate;
this.deliveryAddress = deliveryAddress;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Order order = (Order) o;
return Objects.equals(orderId, order.orderId);
}
@Override
public int hashCode() {
return Objects.hash(orderId);
}
}
启动类
package com.et.sharding.jdbc;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Main {
public static void main(String[] args) {
SpringApplication.run(Main.class, args);
}
}
4.测试
编写测试类
package com.et;
import com.et.sharding.jdbc.*;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.DynamicPropertyRegistry;
import org.springframework.test.context.DynamicPropertySource;
import org.testcontainers.containers.MySQLContainer;
import org.testcontainers.junit.jupiter.Container;
import org.testcontainers.junit.jupiter.Testcontainers;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.LocalDate;
import java.util.List;
/**
* This Manual test requires: Docker service running.
*/
@Testcontainers
@SpringBootTest(classes = Main.class)
class OrderServiceManualTest {
@Container
static MySQLContainer<?> mySQLContainer1 = new MySQLContainer<>("mysql:8.0.23")
.withDatabaseName("ds0")
.withUsername("test")
.withPassword("test");
@Container
static MySQLContainer<?> mySQLContainer2 = new MySQLContainer<>("mysql:8.0.23")
.withDatabaseName("ds1")
.withUsername("test")
.withPassword("test");
static {
mySQLContainer2.setPortBindings(List.of("13307:3306"));
mySQLContainer1.setPortBindings(List.of("13306:3306"));
}
@Autowired
private OrderService orderService;
@Autowired
private OrderRepository orderRepository;
@DynamicPropertySource
static void setProperties(DynamicPropertyRegistry registry) {
registry.add("spring.jpa.hibernate.ddl-auto", () -> "create-drop");
}
@Test
void shouldFindOrderInCorrectShard() {
// given
Order order1 = new Order(1L, 1L, BigDecimal.TEN, Status.PROCESSING, LocalDate.now(), "123 Main St");
Order order2 = new Order(2L, 2L, BigDecimal.valueOf(12.5), Status.SHIPPED, LocalDate.now(), "456 Main St");
// when
Order savedOrder1 = orderService.createOrder(order1);
Order savedOrder2 = orderService.createOrder(order2);
// then
// Assuming the sharding strategy is based on the order id, data for order1 should be present only in ds0
// and data for order2 should be present only in ds1
Assertions.assertThat(orderService.getOrder(savedOrder1.getOrderId())).isEqualTo(savedOrder1);
Assertions.assertThat(orderService.getOrder(savedOrder2.getOrderId())).isEqualTo(savedOrder2);
// Verify that the orders are not present in the wrong shards.
// You would need to implement these methods in your OrderService.
// They should use a JdbcTemplate or EntityManager to execute SQL directly against each shard.
Assertions.assertThat(assertOrderInShard(savedOrder1, mySQLContainer2)).isTrue();
Assertions.assertThat(assertOrderInShard(savedOrder2, mySQLContainer1)).isTrue();
}
private boolean assertOrderInShard(Order order, MySQLContainer<?> container) {
try (Connection conn = DriverManager.getConnection(container.getJdbcUrl(), container.getUsername(), container.getPassword())) {
PreparedStatement stmt = conn.prepareStatement("SELECT * FROM `order` WHERE order_id = ?");
stmt.setLong(1, order.getOrderId());
ResultSet rs = stmt.executeQuery();
return rs.next();
} catch (SQLException ex) {
throw new RuntimeException("Error querying order in shard", ex);
}
}
}
执行单元测试,单元测试通过,说明分库分表规则符合预期
5.引用