基于Sharding-Jdbc 实现的读写分离实现

1. pom 文件依赖

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.2.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
  </parent>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <optional>true</optional>
    </dependency>
    <dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus-boot-starter</artifactId>
      <version>3.0-beta</version>
    </dependency>
    <dependency>
      <groupId>io.shardingjdbc</groupId>
      <artifactId>sharding-jdbc-core</artifactId>
      <version>2.0.3</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>

  </build>

2. application配置

server:
  port: 9002
mybatis-plus:
#  mapper-locations: classpath*:/mapper/*.xml
  global-config:
    db-config:
      column-underline: true
#shardingjdbc配置      
sharding:
  jdbc:
    data-sources:
     ###配置第一个从数据库
      ds_slave_0:
        password: root
        jdbc-url: jdbc:mysql://192.168.212.203:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true
        driver-class-name: com.mysql.jdbc.Driver
        username: root
      ###主数据库配置  
      ds_master:
        password: root
        jdbc-url: jdbc:mysql://192.168.212.202:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true
        driver-class-name: com.mysql.jdbc.Driver
        username: root
    ###配置读写分离    
    master-slave-rule:
    ###配置从库选择策略，提供轮询与随机，这里选择用轮询
      load-balance-algorithm-type: round_robin
      ####指定从数据库
      slave-data-source-names: ds_slave_0
      name: ds_ms
      ####指定主数据库
      master-data-source-name: ds_master

3 .master 和 slave 配置文件。

import java.sql.SQLException;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.google.common.collect.Maps;

import io.shardingjdbc.core.api.MasterSlaveDataSourceFactory;
import lombok.extern.log4j.Log4j2;

@Configuration
@EnableConfigurationProperties(ShardingMasterSlaveConfig.class)
@Log4j2
// 读取ds_master主数据源和读写分离配置
@ConditionalOnProperty({ "sharding.jdbc.data-sources.ds_master.jdbc-url",
    "sharding.jdbc.master-slave-rule.master-data-source-name" })
public class ShardingDataSourceConfig {

  @Autowired
  private ShardingMasterSlaveConfig shardingMasterSlaveConfig;

  @Bean
  public DataSource masterSlaveDataSource() throws SQLException {
    final Map<String, DataSource> dataSourceMap = Maps.newHashMap();
    dataSourceMap.putAll(shardingMasterSlaveConfig.getDataSources());
    final Map<String, Object> newHashMap = Maps.newHashMap();
    // 创建 MasterSlave数据源
    DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource(dataSourceMap,
        shardingMasterSlaveConfig.getMasterSlaveRule(), newHashMap);
    log.info("masterSlaveDataSource config complete");
    return dataSource;
  }

}

import java.util.HashMap;
import java.util.Map;

import org.springframework.boot.context.properties.ConfigurationProperties;

import com.zaxxer.hikari.HikariDataSource;

import io.shardingjdbc.core.api.config.MasterSlaveRuleConfiguration;
import lombok.Data;

@Data
@ConfigurationProperties(prefix = "sharding.jdbc")
public class ShardingMasterSlaveConfig {

  // 存放本地多个数据源
  private Map<String, HikariDataSource> dataSources = new HashMap<>();

  private MasterSlaveRuleConfiguration masterSlaveRule;
}