Springboot实现多数据源切换详情-编程学习网

1. 实现效果

1.1 controller

最终实现效果，在接口上标记上 @Router 注解用来标记当前接口需要根据参数中的某个字段进行数据的切换

@RestController
@RequestMapping("/user")
public class UserController {

    @Resource
    private UserMapper userMapper;

    @GetMapping("/save")
    @Router(routingFiled = "id")
    @Transactional
    public void saveUser(@RequestParam("id") String id){
        User user = new User();
        user.setAge("123");
        user.setId(Long.valueOf(id));
        user.setName("zs");
        //设置表的后缀名称，在mybatis执行sql时可以获取
        user.setTableSuffix(MultiDataSourceHolder.getTableIndex());
        userMapper.insert(user);
    }

    @GetMapping("/get")
    @Router(routingFiled = "id")
    public User getUser(@RequestParam("id") String id){
        return userMapper.selectByPrimaryKey(Long.valueOf(id),MultiDataSourceHolder.getTableIndex());
    }
}

1.2 mybatis.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zhj.multiple.mapper.UserMapper">
  <resultMap id="BaseResultMap" type="com.zhj.multiple.entity.User">
    <!--@mbg.generated-->
    <id column="id" jdbcType="BIGINT" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="age" jdbcType="VARCHAR" property="age" />
  </resultMap>

  <sql id="Base_Column_List">
    <!--@mbg.generated-->
    id, `name`, age
  </sql>
  <select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
    <!--@mbg.generated-->
    select 
    <include refid="Base_Column_List" />
      <!--通过${}获取出表名，为什么不是用#呢？因为表名是在内部进行计算，不用担心sql注入的问题，而且$进行获取是直接将表名进行拼接上，不会使用预处理-->
    from user${tableName}
    where id = #{id,jdbcType=BIGINT}
  </select>
  <insert id="insert" keyColumn="id" keyProperty="id" parameterType="com.zhj.multiple.entity.User" useGeneratedKeys="true">
    <!--@mbg.generated-->
    insert into user${tableSuffix} (id ,`name`, age)
    values (#{id},#{name,jdbcType=VARCHAR}, #{age,jdbcType=VARCHAR})
  </insert>

</mapper>

1.3 application.yml

#showSql
logging:
  level:
    com:
      zhj:
        mapper : debug
server:
  port: 8081
# 配置路由分库分表的策略
datasource:
  stragegy:
    dataSourceNum: 2         #库的个数
    tableNum: 2              #表的个数
    routingFiled: 'userId'     #根据哪个字段来进行分库分表
    tableSuffixStyle: '%04d'   #表的索引值 4位补齐  例如：_0003
    tableSuffixConnect: '_'  #表的连接风格 order_
    routingStategy: 'ROUTING_DS_TABLE_STATEGY'  #表的策略，启动时会根据表的策略进行验证
  #配置数据源
  multiple:
    data0:
      user: root
      password: root
      url: jdbc:mysql://192.168.60.46:3306/multiple-0?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      driver: com.mysql.jdbc.Driver
    data1:
      user: root
      password: root
      url: jdbc:mysql://192.168.60.46:3306/multiple-1?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      driver: com.mysql.jdbc.Driver

1.4 启动类

@SpringBootApplication
@EnableAspectJAutoProxy
@MapperScan("com.zhj.multiple.mapper")
@EnableTransactionManagement
public class MultipleApplication {

    public static void main(String[] args) {
        SpringApplication.run(MultipleApplication.class, args);
    }

}

2. 注解

2.1 @Router


@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Documented
public @interface Router {

    
    String routingFiled() default MultipleConstant.DEFAULT_ROUTING_FIELD;
}

3. 分库策略

3.1 MultipleConstant

目前有三种分库的策略：

多库多表
多库单表
单库多表

@Data
public class MultipleConstant {
    
    public static final String ROUTING_DS_TABLE_STATEGY = "ROUTING_DS_TABLE_STATEGY";

    
    public static final String ROUTGING_DS_STATEGY = "ROUTGING_DS_STATEGY";

    
    public static final String ROUTGIN_TABLE_STATEGY = "ROUTGIN_TABLE_STATEGY";

    
    public static final String DEFAULT_ROUTING_FIELD = "accountId";
}

3.2 IRoutingInterface

路由的顶级接口，用于定义一些通用的方法

public interface IRoutingInterface {

    
    String calDataSourceKey(String routingFiled);

    
    Integer getRoutingFileHashCode(String routingFiled);

    
    String calTableKey(String routingFiled);

    
    String getFormatTableSuffix(Integer tableIndex);

}

3.3 AbstractRouting

@EnableConfigurationProperties({MultipleStategyProperties.class})
@Data
@Slf4j
public abstract class AbstractRouting implements IRoutingInterface, InitializingBean {
    @Resource
    private MultipleStategyProperties multipleStategyProperties;
    @Override
    public Integer getRoutingFileHashCode(String routingFiled){
        return Math.abs(routingFiled.hashCode());
    }
    
    @Override
    public String getFormatTableSuffix(Integer tableIndex){
        //获取连接符
        String tableSuffixConnect = multipleStategyProperties.getTableSuffixConnect();
        //根据配置风格格式化表后缀名称
        String format = String.format(multipleStategyProperties.getTableSuffixStyle(), tableIndex);
        return tableSuffixConnect + format;
    }


    
    @Override
    public void afterPropertiesSet(){
        switch (multipleStategyProperties.getRoutingStategy()) {
            case MultipleConstant.ROUTING_DS_TABLE_STATEGY:
                checkRoutingDsTableStategyConfig();
                break;
            case MultipleConstant.ROUTGING_DS_STATEGY:
                checkRoutingDsStategyConfig();
                break;
            default:
                checkRoutingTableStategyConfig();
                break;
        }
    }

    
    private void checkRoutingDsTableStategyConfig() {
        if(multipleStategyProperties.getTableNum()<=1 ||multipleStategyProperties.getDataSourceNum()<=1){
            log.error("你的配置项routingStategy:{}是多库多表配置,数据库个数>1," +
                            "每一个库中表的个数必须>1,您的配置:数据库个数:{},表的个数:{}",multipleStategyProperties.getRoutingStategy(),
                    multipleStategyProperties.getDataSourceNum(),multipleStategyProperties.getTableNum());
            throw new RuntimeException();
        }
    }
    
    private void checkRoutingDsStategyConfig() {
        if(multipleStategyProperties.getTableNum()!=1 ||multipleStategyProperties.getDataSourceNum()<=1){
            log.error("你的配置项routingStategy:{}是多库一表配置,数据库个数>1," +
                            "每一个库中表的个数必须=1,您的配置:数据库个数:{},表的个数:{}",multipleStategyProperties.getRoutingStategy(),
                    multipleStategyProperties.getDataSourceNum(),multipleStategyProperties.getTableNum());
            throw new RuntimeException();
        }
    }

    
    private void checkRoutingTableStategyConfig() {
        if(multipleStategyProperties.getTableNum()<=1 ||multipleStategyProperties.getDataSourceNum()!=1){
            log.error("你的配置项routingStategy:{}是一库多表配置,数据库个数=1," +
                            "每一个库中表的个数必须>1,您的配置:数据库个数:{},表的个数:{}",multipleStategyProperties.getRoutingStategy(),
                    multipleStategyProperties.getDataSourceNum(),multipleStategyProperties.getTableNum());
            throw new RuntimeException();
        }
    }

}

3.4 RoutingDsAndTbStrategy

目前实现了一个多库多表的策略进行配置，其余两个分库算法可以自行实现

@Slf4j
public class RoutingDsAndTbStrategy extends AbstractRouting {
    
    @Override
    public String calDataSourceKey(String routingFiled) {
        //计算hash值
        Integer routingFileHashCode = getRoutingFileHashCode(routingFiled);

        //定位数据源
        int dsIndex = routingFileHashCode % getMultipleStategyProperties().getDataSourceNum();

        String dataSourceKey = getMultipleStategyProperties().getDataSourceKeysMapping().get(dsIndex);

        //将数据源key放入持有器当中
        MultiDataSourceHolder.setDataSourceHolder(dataSourceKey);

        log.info("根据路由字段:{},值:{},计算出数据库索引值:{},数据源key的值:{}",getMultipleStategyProperties().getRoutingFiled(),routingFiled,dsIndex,dataSourceKey);

        return dataSourceKey;
    }

    
    @Override
    public String calTableKey(String routingFiled) {
        //获取到当前key的hash
        Integer routingFileHashCode = getRoutingFileHashCode(routingFiled);
        //通过hash值取模，获取到对应的索引值
        int tbIndex = routingFileHashCode % getMultipleStategyProperties().getTableNum();

        //获取表后缀
        String formatTableSuffix = getFormatTableSuffix(tbIndex);
        //将表名设置到上下文中，方便后续同线程获取到对应的表名
        MultiDataSourceHolder.setTableIndexHolder(formatTableSuffix);

        return formatTableSuffix;
    }
}

3.5 RoutingDsStrategy

多库单表：

public class RoutingDsStrategy extends AbstractRouting {
    @Override
    public String calDataSourceKey(String routingFiled) {
        return null;
    }

    @Override
    public String calTableKey(String routingFiled) {
        return null;
    }
}

3.6 RoutingTbStrategy

单库多表策略：

public class RoutingTbStrategy extends AbstractRouting {
    @Override
    public String calDataSourceKey(String routingFiled) {
        return null;
    }

    @Override
    public String calTableKey(String routingFiled) {
        return null;
    }
}

4. 配置类

以下两个配置：

MultipleStategyProperties：用于配置数据库策略，有多少库，多少表，以及表名

4.1 MultipleStategyProperties

@ConfigurationProperties(prefix = "datasource.stragegy")
@Data
public class MultipleStategyProperties {
    
    private Integer dataSourceNum = 1;

    
    private Integer tableNum = 1;

    
    private String routingFiled;

    
    private Map<Integer,String> dataSourceKeysMapping;

    
    private String tableSuffixConnect="_";

    
    private String tableSuffixStyle= "%04d";


    
    private String routingStategy = MultipleConstant.ROUTING_DS_TABLE_STATEGY;
}

4.2 MultipleStategyProperties

@Configuration
public class MultipleDataSourceStrategyConfig {

    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTING_DS_TABLE_STATEGY")
    public IRoutingInterface routingDsAndTbStrategy(){
        return new RoutingDsAndTbStrategy();
    }
    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTGING_DS_STATEGY")
    public IRoutingInterface routingDsStrategy(){
        return new RoutingDsStrategy();
    }

    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTGIN_TABLE_STATEGY")
    public IRoutingInterface routingTbStrategy(){
        return new RoutingTbStrategy();
    }
}

4.3 MultipleDataSourceStrategyConfig

根据对应的配置创建不同的分库策略

@Configuration
public class MultipleDataSourceStrategyConfig {
    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTING_DS_TABLE_STATEGY")
    public IRoutingInterface routingDsAndTbStrategy(){
        return new RoutingDsAndTbStrategy();
    }

    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTGING_DS_STATEGY")
    public IRoutingInterface routingDsStrategy(){
        return new RoutingDsStrategy();
    }

    
    @Bean
    @ConditionalOnProperty(prefix = "datasource.stragegy",name = "routingStategy",havingValue = "ROUTGIN_TABLE_STATEGY")
    public IRoutingInterface routingTbStrategy(){
        return new RoutingTbStrategy();
    }
}

4.4 MultipleDataSourceConfig

多数据源自动装配类，其中创建了多个数据源，通过 spring提供的 AbstractRoutingDataSource 类进行数据源的切换

@Configuration
//开启数据源以及数据分库策略配置
@EnableConfigurationProperties({MultipleDataSourceProperties.class, MultipleStategyProperties.class})
public class MultipleDataSourceConfig {

    @Resource
    private MultipleDataSourceProperties multipleDataSourceProperties;
    @Resource
    private MultipleStategyProperties multipleStategyProperties;

    
    @Bean("data0")
    public DataSource dataSource0(){
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUsername(multipleDataSourceProperties.getData0().getUser());
        druidDataSource.setPassword(multipleDataSourceProperties.getData0().getPassword());
        druidDataSource.setUrl(multipleDataSourceProperties.getData0().getUrl());
        druidDataSource.setDriverClassName(multipleDataSourceProperties.getData0().getDriver());
        return druidDataSource;
    }
    @Bean("data1")
    public DataSource dataSource1(){
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setUsername(multipleDataSourceProperties.getData1().getUser());
        druidDataSource.setPassword(multipleDataSourceProperties.getData1().getPassword());
        druidDataSource.setUrl(multipleDataSourceProperties.getData1().getUrl());
        druidDataSource.setDriverClassName(multipleDataSourceProperties.getData1().getDriver());
        return druidDataSource;
    }

    
    @Bean
    public MultiDataSource multiDataSource(DataSource data0,DataSource data1){
        //将多个数据与数据源关联起来
        MultiDataSource multiDataSource = new MultiDataSource();
        HashMap<Object, Object> multiMap = new HashMap<>();
        multiMap.put("data0",data0);
        multiMap.put("data1",data1);
        //设置目标数据源
        multiDataSource.setTargetDataSources(multiMap);
        //设置默认的数据源
        multiDataSource.setDefaultTargetDataSource(data0);
        //设置数据源名称的映射
        Map<Integer, String> multiMappings = new HashMap<>();
        multiMappings.put(0,"data0");
        multiMappings.put(1,"data1");
        multipleStategyProperties.setDataSourceKeysMapping(multiMappings);

        return multiDataSource;
    }

    
    @Bean
    public SqlSessionFactory sqlSessionFactory(@Qualifier("multiDataSource") MultiDataSource multiDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(multiDataSource);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:/mybatis/mappers
    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(@Qualifier("multiDataSource") MultiDataSource multiDataSource){
        return new DataSourceTransactionManager(multiDataSource);
    }
}

4.5 MultiDataSource

覆写 AbstractRoutingDataSource.determineCurrentLookupKey() 的方法，在mybatis中通过 Datasource.getConnection() 会调用 determineCurrentLookupKey() 获取到对应的数据源，然后通过数据源获取到连接，其中内部维护了一个 Map 来保存数据源的映射关系

public class MultiDataSource extends AbstractRoutingDataSource {

    
    @Override
    protected Object determineCurrentLookupKey() {
        return MultiDataSourceHolder.getDataSourceKey();
    }
}

5. 全局上下文

用于保存数据库、表名，方便后续使用

5.1 MultiDataSourceHolder

@Data
public class MultiDataSourceHolder {
    
    private static final ThreadLocal<String> dataSourceHolder = new ThreadLocal<>();
    
    private static final ThreadLocal<String> tableIndexHolder = new ThreadLocal<>();

    
    public static String getDataSourceKey(){
        return dataSourceHolder.get();
    }

    
    public static String getTableIndex(){
        return tableIndexHolder.get();
    }
    
    public static void clearDataSourceKey(){
        dataSourceHolder.remove();
    }

    
    public static void clearTableIndex(){
        tableIndexHolder.remove();
    }

    
    public static void setDataSourceHolder(String key){
        dataSourceHolder.set(key);
    }

    
    public static void setTableIndexHolder(String key){
        tableIndexHolder.set(key);
    }
}

6. 切面

6.1 RoutingAspect

通过路由切面进行 @Router 注解的处理，提前将数据库的key以及表名的后缀获取出来进行存储

@Aspect
@Component
@Slf4j
public class RoutingAspect {
    @Resource
    private IRoutingInterface iRoutingInterface;
    
    @Pointcut("@annotation(com.zhj.multiple.annotations.Router)")
    public void pointCut(){};

    @Before("pointCut()")
    public void before(JoinPoint joinPoint) throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
        long beginTime = System.currentTimeMillis();
        //获取方法调用名称
        Method method = getInvokeMethod(joinPoint);
        //获取方法指定的注解
        Router router = method.getAnnotation(Router.class);
        //获取指定的路由key
        String routingFiled = router.routingFiled();

        if(Objects.nonNull(router)){
            boolean havingRoutingField = false;
            //获取到http请求
            HttpServletRequest requestAttributes = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
            //优先获取@ReqeustParam注解中的路由字段
            String routingFieldValue = requestAttributes.getParameter(routingFiled);
            if(!StringUtils.isEmpty(routingFieldValue)){
                //计算数据库key
                String dbKey = iRoutingInterface.calDataSourceKey(routingFieldValue);
                //计算表索引
                String tableIndex = iRoutingInterface.calTableKey(routingFieldValue);
                log.info("选择的dbkey是:{},tableKey是:{}",dbKey,tableIndex);
            }else {
                //获取方法入参
                Object[] args = joinPoint.getArgs();
                if(args != null && args.length > 0) {
                    for(int index = 0; index < args.length; index++) {
                        //找到参数当中路由字段的值
                        routingFieldValue = BeanUtils.getProperty(args[index],routingFiled);
                        if(!StringUtils.isEmpty(routingFieldValue)) {
                            //计算数据库key
                            String dbKey = iRoutingInterface.calDataSourceKey(routingFieldValue);
                            //计算表索引
                            String tableIndex = iRoutingInterface.calTableKey(routingFieldValue);
                            log.info("选择的dbkey是:{},tableKey是:{}",dbKey,tableIndex);
                            havingRoutingField = true;
                            break;
                        }
                    }
                    //判断入参中没有路由字段
                    if(!havingRoutingField) {
                        log.warn("入参{}中没有包含路由字段:{}",args,routingFiled);
                        throw new RuntimeException();
                    }
                }
            }
        }
    }
    private Method getInvokeMethod(JoinPoint joinPoint) {
        Signature signature = joinPoint.getSignature();
        MethodSignature methodSignature = (MethodSignature)signature;
        Method targetMethod = methodSignature.getMethod();
        return targetMethod;
    }

    
    @After("pointCut()")
    public void methodAfter(JoinPoint joinPoint){
        MultiDataSourceHolder.clearDataSourceKey();
        MultiDataSourceHolder.clearTableIndex();
    }
}

到此这篇关于Springboot实现多数据源切换详情的文章就介绍到这了,更多相关Springboot多数据源切换内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！

文章详情

Springboot实现多数据源切换详情

目录

1. 实现效果

1.1 controller

1.2 mybatis.xml

1.3 application.yml

1.4 启动类

2. 注解

2.1 @Router

3. 分库策略

3.1 MultipleConstant

3.2 IRoutingInterface

3.3 AbstractRouting

3.4 RoutingDsAndTbStrategy

3.5 RoutingDsStrategy

3.6 RoutingTbStrategy

4. 配置类

4.1 MultipleStategyProperties

4.2 MultipleStategyProperties

4.3 MultipleDataSourceStrategyConfig

4.4 MultipleDataSourceConfig

4.5 MultiDataSource

5. 全局上下文

5.1 MultiDataSourceHolder

6. 切面

6.1 RoutingAspect

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