sharding-jdbc读写分离的使用详解

一、不使用Spring

1、引入Maven依赖

    io.shardingsphere
    sharding-jdbc-core
    ${sharding-sphere.version}

2、基于Java编码的规则配置

// 配置真实数据源
    Map<String, DataSource> dataSourceMap = new HashMap<>();
    
    // 配置主库
    BasicDataSource masterDataSource = new BasicDataSource();
    masterDataSource.setDriverClassName("com.mysql.jdbc.Driver");
    masterDataSource.setUrl("jdbc:mysql://localhost:3306/ds_master");
    masterDataSource.setUsername("root");
    masterDataSource.setPassword("");
    dataSourceMap.put("ds_master", masterDataSource);
    
    // 配置第一个从库
    BasicDataSource slaveDataSource1 = new BasicDataSource();
    slaveDataSource1.setDriverClassName("com.mysql.jdbc.Driver");
    slaveDataSource1.setUrl("jdbc:mysql://localhost:3306/ds_slave0");
    slaveDataSource1.setUsername("root");
    slaveDataSource1.setPassword("");
    dataSourceMap.put("ds_slave0", slaveDataSource1);
    
    // 配置第二个从库
    BasicDataSource slaveDataSource2 = new BasicDataSource();
    slaveDataSource2.setDriverClassName("com.mysql.jdbc.Driver");
    slaveDataSource2.setUrl("jdbc:mysql://localhost:3306/ds_slave1");
    slaveDataSource2.setUsername("root");
    slaveDataSource2.setPassword("");
    dataSourceMap.put("ds_slave1", slaveDataSource2);
    
    // 配置读写分离规则
    MasterSlaveRuleConfiguration masterSlaveRuleConfig = new MasterSlaveRuleConfiguration("ds_master_slave", "ds_master", Arrays.asList("ds_slave0", "ds_slave1"));
    
    // 获取数据源对象
    DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource(createDataSourceMap(), masterSlaveRuleConfig, new HashMap<String, Object>(), new Properties());

3、基于Yaml的规则配置(与步骤 2 等价)

dataSources:
  ds_master: !!org.apache.commons.dbcp.BasicDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ds_master
    username: root
    password: 
  ds_slave0: !!org.apache.commons.dbcp.BasicDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ds_slave0
    username: root
    password:
  ds_slave1: !!org.apache.commons.dbcp.BasicDataSource
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ds_slave1
    username: root
    password: 

masterSlaveRule:
  name: ds_ms
  masterDataSourceName: ds_master
  slaveDataSourceNames: [ds_slave0, ds_slave1]
  
  props:
      sql.show: true
  configMap:
      key1: value1

利用DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource(yamlFile);获取数据源

4、使用原生JDBC

通过MasterSlaveDataSourceFactory工厂和规则配置对象获取MasterSlaveDataSource，MasterSlaveDataSource实现自JDBC的标准接口DataSource。然后可通过DataSource选择使用原生JDBC开发，或者使用JPA, MyBatis等ORM工具。 以JDBC原生实现为例：

DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource(yamlFile);
String sql = "SELECT i.* FROM t_order o JOIN t_order_item i ON o.order_id=i.order_id WHERE o.user_id=? AND o.order_id=?";
try (
        Connection conn = dataSource.getConnection();
        PreparedStatement preparedStatement = conn.prepareStatement(sql)) {
    preparedStatement.setInt(1, 10);
    preparedStatement.setInt(2, 1001);
    try (ResultSet rs = preparedStatement.executeQuery()) {
        while(rs.next()) {
            System.out.println(rs.getInt(1));
            System.out.println(rs.getInt(2));
        }
    }
}

---

二、使用Spring

1、引入Maven依赖

<dependency>
    <groupId>io.shardingspheregroupId>
    <artifactId>sharding-jdbc-spring-boot-starterartifactId>
    <version>${sharding-sphere.version}version>
dependency>


<dependency>
    <groupId>io.shardingspheregroupId>
    <artifactId>sharding-jdbc-spring-namespaceartifactId>
    <version>${sharding-sphere.version}version>
dependency>

2、基于Spring boot的规则配置

sharding.jdbc.datasource.names=master,slave0,slave1

sharding.jdbc.datasource.master.type=org.apache.commons.dbcp.BasicDataSource
sharding.jdbc.datasource.master.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.master.url=jdbc:mysql://localhost:3306/master
sharding.jdbc.datasource.master.username=root
sharding.jdbc.datasource.master.password=

sharding.jdbc.datasource.slave0.type=org.apache.commons.dbcp.BasicDataSource
sharding.jdbc.datasource.slave0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.slave0.url=jdbc:mysql://localhost:3306/slave0
sharding.jdbc.datasource.slave0.username=root
sharding.jdbc.datasource.slave0.password=

sharding.jdbc.datasource.slave1.type=org.apache.commons.dbcp.BasicDataSource
sharding.jdbc.datasource.slave1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.slave1.url=jdbc:mysql://localhost:3306/slave1
sharding.jdbc.datasource.slave1.username=root
sharding.jdbc.datasource.slave1.password=

sharding.jdbc.config.masterslave.name=ms
sharding.jdbc.config.masterslave.master-data-source-name=master
sharding.jdbc.config.masterslave.slave-data-source-names=slave0,slave1

sharding.jdbc.config.props.sql.show=true

3、基于Spring命名空间的规则配置

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:master-slave="http://shardingsphere.io/schema/shardingsphere/masterslave" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://shardingsphere.io/schema/shardingsphere/masterslave 
                        http://shardingsphere.io/schema/shardingsphere/masterslave/master-slave.xsd 
                        ">
    <bean id="ds_master" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/ds_master" />
        <property name="username" value="root" />
        <property name="password" value="" />
    bean>
    <bean id="ds_slave0" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/ds_slave0" />
        <property name="username" value="root" />
        <property name="password" value="" />
    bean>
    <bean id="ds_slave1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/ds_slave1" />
        <property name="username" value="root" />
        <property name="password" value="" />
    bean>
    
    <master-slave:data-source id="masterSlaveDataSource" master-data-source-name="ds_master" slave-data-source-names="ds_slave0, ds_slave1" >
        <master-slave:props>
                <prop key="sql.show">${sql_show}prop>
                <prop key="executor.size">10prop>
                <prop key="foo">barprop>
            master-slave:props>
    master-slave:data-source>
beans>

4、在Spring中使用DataSource

@Resource
private DataSource dataSource;

更多配置参考：配置手册 http://shardingsphere.io/document/current/cn/manual/sharding-jdbc/configuration/