读写分离
本文介绍SpringBoot使用Sharding-JDBC进行读写分离，废话不多说，直接写代码。
场景介绍：
- 主库（Master）负责写入。
- 从库（Slave）负责查询。
POM文件
pom文件引入如下相关依赖：
<?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">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
</parent>
<groupId>com.morris</groupId>
<artifactId>shardingsphere-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>4.0.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.11</version>
<exclusions>
<exclusion>
<groupId>com.alibaba</groupId>
<artifactId>jconsole</artifactId>
</exclusion>
<exclusion>
<groupId>com.alibaba</groupId>
<artifactId>tools</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>aliyun</id>
<name>aliyun</name>
<url>http://maven.aliyun.com/nexus/content/groups/public</url>
</repository>
</repositories>
</project>OrderController
package com.morris.controller;
import com.morris.entity.Order;
import com.morris.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
@RequestMapping("order")
public class OrderController {
@Autowired
private OrderService orderService;
@RequestMapping("list")
public List<Order> list() {
return orderService.list();
}
@RequestMapping("add")
public String add() {
Order order = Order.builder().userId(10).status("成功").build();
orderService.add(order);
return "success";
}
}OrderService
package com.morris.service;
import com.morris.entity.Order;
import java.util.List;
public interface OrderService {
List<Order> list();
void add(Order order);
}OrderServiceImpl
package com.morris.service.impl;
import com.morris.entity.Order;
import com.morris.mapper.OrderMapper;
import com.morris.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
private OrderMapper orderMapper;
@Override
public List<Order> list() {
return orderMapper.list();
}
@Override
public void add(Order order) {
orderMapper.insert(order);
}
}OrderMapper
package com.morris.mapper;
import com.morris.entity.Order;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;
@Mapper
public interface OrderMapper {
@Select("select * from t_order")
List<Order> list();
@Select("insert into t_order(user_id, status) values(#{userId}, #{status})")
void insert(Order order);
}Order
package com.morris.entity;
import lombok.Builder;
import lombok.Data;
@Data
@Builder
public class Order {
private Long orderId;
private Integer userId;
private String status;
}Application
package com.morris;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.morris.mapper")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}application.yml
server:
port: 8800
mybatis:
configuration:
map-underscore-to-camel-case: true
use-generated-keys: true
spring:
shardingsphere:
datasource:
names: master,slave
master:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/order-master?useUnicode=true&allowMultiQueries=true&characterEncoding=UTF-8&useFastDateParsing=false&zeroDateTimeBehavior=convertToNull
username: master
password: master
slave:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://127.0.0.1:3306/order-slave?useUnicode=true&allowMultiQueries=true&characterEncoding=UTF-8&useFastDateParsing=false&zeroDateTimeBehavior=convertToNull
username: slave
password: slave
masterslave:
master-data-source-name: master
load-balance-algorithm-type: round_robin # 负责均衡算法
name: dataSource
slave-data-source-names: slave
props:
sql:
show: true验证写数据走主库：
$ curl localhost:8800/order/add
success日志打印如下：
2020-12-23 11:34:26.688 INFO 6404 --- [nio-8800-exec-2] ShardingSphere-SQL : Rule Type: master-slave
2020-12-23 11:34:26.688 INFO 6404 --- [nio-8800-exec-2] ShardingSphere-SQL : SQL: insert into t_order(user_id, status) values(?, ?) ::: DataSources: master验证读数据走从库：
$ curl localhost:8800/order/list
[{"orderId":1,"userId":10,"status":"成功"}]日志打印如下：
2020-12-23 11:34:16.231 INFO 6404 --- [nio-8800-exec-1] ShardingSphere-SQL : Rule Type: master-slave
2020-12-23 11:34:16.231 INFO 6404 --- [nio-8800-exec-1] ShardingSphere-SQL : SQL: select * from t_order ::: DataSources: slave
