spring+mybatis_多數據源配置

時間 2019-11-12

標籤 spring+mybatis spring mybatis 數據配置欄目 MyBatis 简体版

原文原文鏈接

主從數據源配置

分庫分表數據源配置

利用動態數據源和AOP實現分庫

1.application.yml文件中配置多個數據源

spring: 
  http: 
    encoding:
      charset: UTF-8 
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
    default-property-inclusion: NON_NULL      
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    # 多數據源配置
    uts1: 
      url: jdbc:mysql://192.168.99.100:3306/uts1?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: 111111
    uts2: 
      url: jdbc:mysql://192.168.99.100:3306/uts2?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: 111111
    uts3: 
      url: jdbc:mysql://192.168.99.100:3306/uts3?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: 111111
    uts4: 
      url: jdbc:mysql://192.168.99.100:3306/uts4?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: 111111

2.配置多個 datasource bean

@Bean("uts1")
@ConfigurationProperties(prefix = "spring.datasource.uts1")
@Primary
public DataSource uts1DataSource() throws SQLException {
    DruidDataSource ds = new DruidDataSource();
    logger.info(" druid datasource uts1DataSource : {} ", ds);
    return ds;
}

@Bean("uts2")
@ConfigurationProperties(prefix = "spring.datasource.uts2")
public DataSource uts2DataSource() throws SQLException {
    DruidDataSource ds = new DruidDataSource();
    logger.info(" druid datasource uts2DataSource : {} ", ds);
    return ds;
}

@Bean("uts3")
@ConfigurationProperties(prefix = "spring.datasource.uts3")
public DataSource uts3DataSource() throws SQLException {
    DruidDataSource ds = new DruidDataSource();
    logger.info(" druid datasource uts3DataSource : {} ", ds);
    return ds;
}

@Bean("uts4")
@ConfigurationProperties(prefix = "spring.datasource.uts4")
public DataSource uts4DataSource() throws SQLException {
    DruidDataSource ds = new DruidDataSource();
    logger.info(" druid datasource uts4DataSource : {} ", ds);
    return ds;
}

3.定義數據源枚舉類

public class DataBaseContextHolder {
    public enum DataBaseType {
        uts1("uts1"), uts2("uts2"), uts3("uts3"), uts4("uts4");
        private String code;

        DataBaseType(String dbName) {
            code = dbName;
        }

        public String getCode() {
            return code;
        }

        public void setCode(String code) {
            this.code = code;
        }

    }

    private static final ThreadLocal<DataBaseType> contextHolder = new ThreadLocal<>();

    public static Object getDataBaseType() {
        return contextHolder.get() == null ? DataBaseType.uts1 : contextHolder.get();
    }

    public static void setDataBaseType(DataBaseType dataBaseType) {
        if (dataBaseType == null)
            throw new NullPointerException("dataBaseType不容許爲空.");
        contextHolder.set(dataBaseType);
    }

    public static void clearContextHolder() {
        contextHolder.remove();
    }
}

4.定義DynamicDataSource

該類繼承AbstractRoutingDataSource，重寫determineCurrentLookupKey.mysql

public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DataBaseContextHolder.getDataBaseType();
    }
}

5.配置mybatis sqlSessionFactory

@Configuration
@EnableTransactionManagement
public class MybatisConfiguration {
    @Resource(name = "uts1")
    private DataSource duts1DataSource;
    @Resource(name = "uts2")
    private DataSource duts2DataSource;
    @Resource(name = "uts3")
    private DataSource duts3DataSource;
    @Resource(name = "uts4")
    private DataSource duts4DataSource;

    @Bean
    public DynamicDataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataBaseContextHolder.DataBaseType.uts1, duts1DataSource);
        targetDataSources.put(DataBaseContextHolder.DataBaseType.uts2, duts2DataSource);
        targetDataSources.put(DataBaseContextHolder.DataBaseType.uts3, duts3DataSource);
        targetDataSources.put(DataBaseContextHolder.DataBaseType.uts4, duts4DataSource);
        dynamicDataSource.setTargetDataSources(targetDataSources);
        dynamicDataSource.setDefaultTargetDataSource(duts1DataSource);
        return dynamicDataSource;
    }

    @Bean(name = "sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactoryBean(DynamicDataSource dynamicDataSource) {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dynamicDataSource);
        // 添加XML目錄
        ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        try {
            bean.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));
            SqlSessionFactory sqlSessionFactory = bean.getObject();
            sqlSessionFactory.getConfiguration().setCacheEnabled(Boolean.TRUE);

            return sqlSessionFactory;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Bean
    public PlatformTransactionManager transactionManager(DynamicDataSource dynamicDataSource) throws Exception {
        DataSourceTransactionManager txManager = new DataSourceTransactionManager();
        txManager.setDataSource(dynamicDataSource);
        return txManager;
    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

6. 定義數據源註解

@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SelectConnection {
    String name() default "";
}

7. 定義數據源切面

@Aspect
@Component
public class SelectConnectionInterceptor implements Ordered {
    private static final String DB_PREFIX = "uts";

    @Around("@annotation(selectConnection)")
    public Object proceed(ProceedingJoinPoint joinPoint, SelectConnection selectConnection) throws Throwable {
        String dbName = "";
        if (!StringUtils.isBlank(selectConnection.name())) {
            dbName = selectConnection.name();
        } else {
            BaseEntity baseEntity = (BaseEntity) joinPoint.getArgs()[0];
            Pair<Integer, Integer> pair = SelectorUtil.getDataBaseAndTableNumber(baseEntity.getId());
            dbName = DB_PREFIX + pair.getObject1();
        }
        DataBaseContextHolder.setDataBaseType(DataBaseContextHolder.DataBaseType.valueOf(dbName));
        Object result = joinPoint.proceed();
        DataBaseContextHolder.clearContextHolder();
        return result;

    }

    @Override
    public int getOrder() {
        return 0;
    }

}

以上，多數據源的配置就完成了。在service層的方法上，加上@SelectConnection註解，就能夠指定鏈接的數據庫。算法

分表實現

通常來講，若是有10張表，那麼會經過hash算法對ID進行hash,將結果映射到1-10。spring

1.定義hash util類

public class Pair<T1, T2> {
    private T1 object1;
    private T2 object2;

    public Pair(T1 object1, T2 object2) {
        this.object1 = object1;
        this.object2 = object2;
    }

    public T1 getObject1() {
        return object1;
    }

    public void setObject1(T1 object1) {
        this.object1 = object1;
    }

    public T2 getObject2() {
        return object2;
    }

    public void setObject2(T2 object2) {
        this.object2 = object2;
    }
}

public class SelectorUtil {
    public static Pair<Integer, Integer> getDataBaseAndTableNumber(String uid) {
        int hashCode = Math.abs(uid.hashCode());
        int dbNumber = hashCode / 10 % 4 + 1;
        int tableNumber = hashCode % 10;
        return new Pair<Integer, Integer>(dbNumber, tableNumber);
    }
}

2.根據hash算法映射到具體的表

private static final String TABLE_NAME_PREFIX = "trade_detail_";

@SelectConnection
public int balanceInsert(TradeDetail td) {
    String uuid = td.getId();
    Pair<Integer, Integer> pair = SelectorUtil.getDataBaseAndTableNumber(uuid);
    Integer tableNumber = pair.getObject2();
    String tableName = TABLE_NAME_PREFIX + tableNumber;
    System.out.println("當前數據庫:" + pair.getObject1());
    System.out.println("當前表:" + tableName);
    return tradeDetailMapper.balanceInsert(tableName, td);

}