Sharding-Jdbc

1、概念

2、Sharding-Jdbc与Mycat的区别

3、读写分离原理

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.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>

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

@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;
}

@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;
    }
}

MyCat执行原理分析与初始Sharding-Jdbc.pptx上课代码.zip