基于mybaits-plus实现动态数据源

简介

动态数据源，支持多企业多数据源，支持读写分离设计，服务运行过程中，支持动态加入新数据源

实现步骤

动态数据源上下文

import com.alibaba.ttl.TransmittableThreadLocal;
/**
 * kafka通讯协议上下文 需配合TtlExecutors 修饰线程池使用
 */
public class DatabaseContextHolder {
    //TransmittableThreadLocal可实现多线程父子线程变量传递，也可以实现线程池内变量传递，线程池需要TtlExecutors修饰
    private final static TransmittableThreadLocal<String> threadLocal = new TransmittableThreadLocal<>();

    public static String getDatabae(){
        return threadLocal.get();
    }

    public static void setDatabase(String database){
        threadLocal.set(database);
    }

    public static void remove(){

mvc拦截器，通过token获取用户企业信息，然后得到企业数据库，设置本次请求动态数据源上下文 

import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

//自定义Mvc请求拦截器
@Component
@Slf4j
public class DabaseInterceptor extends HandlerInterceptorAdapter {
    private static final String TRACE_ID = "TRACE_ID";

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        //设置动态数据源缓存
        try{
            //根据请求用户信息获取用户对应的数据 根据自身业务逻辑补充
            String database = "";
            DatabaseContextHolder.setDatabase(dabase);
        }catch (Exception e){
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
        DatabaseContextHolder.remove();
    }
}

@Configuration
class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new DabaseInterceptor());
    }
}

动态数据源切面， 切service方法，将数据源上下文数据源设置到mybaits-plus动态数据源中

import cn.hutool.core.annotation.AnnotationUtil;
import com.baomidou.dynamic.datasource.toolkit.DynamicDataSourceContextHolder;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

/**
 * 动态数据源切面
 */
@Component
@Aspect
@Slf4j
public class DynamicDataSourceAspect {
    //切面service包下所有类所有方法 不包括子包
    //@Pointcut("execution(* com.service.*.*(..))")
    //public void point(){};

    //切面需要放在这里，解决mybaits-plus saveBatch无法设置动态数据源问题
    @Pointcut("execution(*    com.baomidou.dynamic.datasource.ds.AbstractRoutingDataSource.getConnection(..))")
    public void point(){};

    @Before(value = "point()")
    public void before(JoinPoint joinPoint){
        MethodSignature methodSignature = (MethodSignature)joinPoint.getSignature();
        Method method = methodSignature.getMethod();
        String ds;
        if(AnnotationUtil.hasAnnotation(method, DynamicDs.class)){
            DynamicDs dynamicDs = method.getAnnotation(DynamicDs.class);
            DynamicDsEnum dynamicDsEnum = dynamicDs.value();
            ds = DatabaseContextHolder.getDatabase + "_" + dynamicDsEnum.getCode();
        }else {
            //未加注解 默认使用写库
            ds = DatabaseContextHolder.getDatabase + "_" + DynamicDsEnum.WRITE.getCode();
        }
        DynamicDataSourceContextHolder.push(ds);
    }
}

动态数据源自定义注解，在方法上加上注解，可以实现读写分离 

/**
 * 动态数据源注解
 */
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DynamicDs {
    //默认写库
    DynamicDsEnum value() default DynamicDsEnum.WRITE;
}

数据源类型枚举类 

/**
 * 数据源类型
 */
@Getter
public enum DynamicDsEnum {
    WRITE("1", "写"),
    READ("2", "读");

    private String code;
    private String desc;

    DynamicDsEnum(String code, String desc){
        this.code = code;
        this.desc = desc;
    }
}

服务启动从数据源配置表加载动态数据源 

import cn.hutool.core.collection.CollUtil;
import com.alibaba.fastjson.JSON;
import com.baomidou.dynamic.datasource.DynamicRoutingDataSource;
import com.baomidou.dynamic.datasource.creator.DefaultDataSourceCreator;
import com.baomidou.dynamic.datasource.spring.boot.autoconfigure.DataSourceProperty;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.sql.DataSource;
import java.util.List;

@Component
@Slf4j
public class DataSourceLoadHandler {
    @Value("${gocom.initDataSource:true}")
    private boolean initDataSource;

    private ISysDatabaseClient sysDatabaseClient;

    private DefaultDataSourceCreator dataSourceCreator;

    private DynamicRoutingDataSource routingDataSource;

    @Resource
    public void setRoutingDataSource(DynamicRoutingDataSource dataSource){
        this.routingDataSource = dataSource;
    }

    @Resource
    public void setDefaultDataSourceCreator(DefaultDataSourceCreator sourceCreator){
        this.dataSourceCreator = sourceCreator;
    }

    @Resource
    public void setSysDatabaseClient(ISysDatabaseClient sysDatabaseClient) {
        this.sysDatabaseClient = sysDatabaseClient;
    }

    @PostConstruct
    public void initDataSources(){
        if(!initDataSource){
            log.info("不加载企业动态数据源");
            return;
        }
        log.info("############开始加载企业数据源#################");
        List<String> list = null;//查询所有数据源配置库
        if(CollUtil.isEmpty(list)){
            return;
        }
        list.forEach(sysCompanyDatabases -> {
            try{
                DataSourceProperty dataSourceProperty = JSON.parseObject(sysCompanyDatabases.getConfigs(), DataSourceProperty.class);
                dataSourceProperty.setPoolName("client-ds-" + sysCompanyDatabases ;
                DataSource dataSource = dataSourceCreator.createDataSource(dataSourceProperty);
                routingDataSource.addDataSource(sysCompanyDatabases , dataSource);
                log.info("企业数据源加载成功:{}", sysCompanyDatabases.getId());
            }catch (Exception e){
                log.error("企业数据源加载异常:{}", sysCompanyDatabases.getId());
            }

        });
        log.info("############加载企业数据源完成#################");

    }
}