2.x微服务踩坑之多数据源

目录
  • 一、1.x版本配置
  • 二、2.x版本配置
  • 三、1.x 与 2.x 踩坑

【注】 踩坑是根据公司需求对原有代码进行升级，这里只对单纯的技术配置代码进行展示不涉及公司业务。公司采用的是properties这里就使用properties进行配置



一、1.x数据源配置

Nacos Java Client serverAddr 多地址负载均衡_spring boot

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-parent</artifactId>
        <version>1.5.9.RELEASE</version>
</parent>

application.properties文件

# 主数据源
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://127.0.0.1:3305/lgg_zone
spring.datasource.username=root
spring.datasource.password=root
# 备用数据源1
custom.datasource.names = lgg-one, lgg-two
custom.datasource.lgg-one.type=com.alibaba.druid.pool.DruidDataSource
custom.datasource.lgg-one.driverClassName = com.mysql.jdbc.Drive
custom.datasource.lgg-one.url = jdbc:mysql://127.0.0.1:3306/lgg_one
custom.datasource.lgg-one.username=root
custom.datasource.lgg-one.password=root
# 备用数据源2
custom.datasource.lgg-two.type=com.alibaba.druid.pool.DruidDataSource
custom.datasource.lgg-two.driverClassName = com.mysql.jdbc.Drive
custom.datasource.lgg-two.url = jdbc:mysql://127.0.0.1:3307/lgg_two
custom.datasource.lgg-two.username=root
custom.datasource.lgg-two.password=root
package com.lxn.eureka.datasource1_x;

import java.lang.annotation.*;

/**
 * @author: ligangan
 * @Description 定义切换数据源的注解
 */
@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource {
    String name();
}
package com.lxn.eureka.datasource1_x;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:58
 * 动态数据源
 */
public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}
package com.lxn.eureka.datasource1_x;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 * 切换数据源Advice
 */
@Aspect
@Order(-1) // 保证该AOP在@Transactional 之前执行
@Component
public class DynamicDataSourceAspect {
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class);

    @Before("@annotation(ds)")
    public void changeDataSource(JoinPoint joinPoint, TargetDataSource ds)  throws Throwable{
        String dsId = ds.name();
        if(!DynamicDataSourceContextHolder.containsDataSource(dsId)){
            logger.error("数据源[{}]不存在，使用默认数据源>{}",ds.name(), joinPoint.getSignature());
        }else{
            logger.debug("Use DataSource: {} > {}",ds.name(), joinPoint.getSignature());
            DynamicDataSourceContextHolder.setDataSourceType(ds.name());
        }
    }
    @After("@annotation(ds)")
    public void restoreDataSource(JoinPoint joinPoint, TargetDataSource ds){
        logger.debug("Use DataSource: {} > {}",ds.name(), joinPoint.getSignature());
        DynamicDataSourceContextHolder.clearDataSourceType();
    }
}
package com.lxn.eureka.datasource1_x;

import java.util.ArrayList;
import java.util.List;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 * 判断指定DataSource 当前是否存在
 */
public class DynamicDataSourceContextHolder {

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
    public static List<String> dataSourceIds = new ArrayList<>();

    public static void setDataSourceType(String dataSourceType) {
        contextHolder.set(dataSourceType);
    }
    public static String getDataSourceType(){
        return contextHolder.get();
    }
    public static void clearDataSourceType () {
        contextHolder.remove();
    }
    public static boolean containsDataSource(String dataSourceId) {
        return dataSourceIds.contains(dataSourceId);
    }
}
package com.lxn.eureka.datasource1_x;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.bind.RelaxedDataBinder;
import org.springframework.boot.bind.RelaxedPropertyResolver;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotationMetadata;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 */
public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware {

    private static final Logger logger = LoggerFactory.getLogger(com.lxn.eureka.datasource1_x.DynamicDataSourceRegister.class);

    private ConversionService conversionService = new DefaultConversionService();

    private PropertyValues dataSourcePropertyValues;
    /**
     * 如果配置文件中未指定数据源类型，使用该默认值
     */
    private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.DataSource";
    /**
     * 数据源
     */
    private DataSource defaultDataSource;

    private Map<String,DataSource> customDataSources = new HashMap<>();

    @Override
    public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry beanDefinitionRegistry) {
        Map<Object,Object> targetDataSources = new HashMap<Object,Object>();
        // 将主数据源添加到更多数据源中
        targetDataSources.put("dataSource",defaultDataSource);
        DynamicDataSourceContextHolder.dataSourceIds.add("dataSource");
        // 添加更多数据源
        targetDataSources.putAll(customDataSources);
        for (String key : customDataSources.keySet()) {
            DynamicDataSourceContextHolder.dataSourceIds.add(key);
        }

        // 创建DynamicDataSource
        GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
        beanDefinition.setBeanClass(DynamicDataSource.class);
        beanDefinition.setSynthetic(true);
        MutablePropertyValues mvp = beanDefinition.getPropertyValues();
        mvp.addPropertyValue("defaultTargetDataSource",defaultDataSource);
        mvp.addPropertyValue("targetDataSources",targetDataSources);
        beanDefinitionRegistry.registerBeanDefinition("dataSource", beanDefinition);

        logger.info("Dynamic DataSource Registry");
    }

    /**
     * 创建DataSource
     */
    @SuppressWarnings("unchecked")
    public DataSource buildDataSource(Map<String,Object> dsMap) {
        try {
            Object type = dsMap.get("type");
            if(type == null) {
                type = DATASOURCE_TYPE_DEFAULT; // 默认DataSource
            }
            Class<? extends  DataSource> dataSourceType;
            dataSourceType = (Class<? extends DataSource>) Class.forName((String)type);
            String driverClassName = dsMap.get("driverClassName").toString();
            String url = dsMap.get("url").toString();
            String username = dsMap.get("username").toString();
            String password = dsMap.get("password").toString();

            DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url).username(username).password(password).type(dataSourceType);
            return factory.build();
        }catch (ClassNotFoundException e) {
            logger.error("buildDataSource error", e);
        }
        return null;
    }

    /**
     * 加载多数据源
     * @param environment
     */
    @Override
    public void setEnvironment(Environment env) {
        initDefaultDataSource(env);
        initCustomDataSource(env);
    }

    /**
     * 初始化主数据源
     * @param env
     */
    private void initDefaultDataSource(Environment env) {
        // 读取主数据源
        RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env,"spring.datasource.");
        HashMap<String, Object> dsMap = new HashMap<>();
        dsMap.put("type",propertyResolver.getProperty("type"));
        dsMap.put("driverClassName",propertyResolver.getProperty("driverClassName"));
        dsMap.put("url",propertyResolver.getProperty("url"));
        dsMap.put("username",propertyResolver.getProperty("username"));
        dsMap.put("password",propertyResolver.getProperty("password"));

        defaultDataSource = buildDataSource(dsMap);
        dataBinder(defaultDataSource,env);
    }

    /**
     * 初始化更多数据源
     * @param env
     */
    private void initCustomDataSource(Environment env) {
        // 读取配置文件获取更多数据源，也可以通过defaultDataSource读取数据库获取更多数据源
        RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver(env,"custom.datasource.");
        String dsPrefixs = propertyResolver.getProperty("names");
        for (String dsPrefix : dsPrefixs.split(",")) {
            Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix+ ".");
            DataSource ds = buildDataSource(dsMap);
            customDataSources.put(dsPrefix,ds);
            dataBinder(ds,env);
        }
    }

    private void dataBinder(DataSource dataSource, Environment env) {
        RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource);

        dataBinder.setConversionService(conversionService);
        dataBinder.setIgnoreNestedProperties(false);
        dataBinder.setIgnoreInvalidFields(false);
        dataBinder.setIgnoreUnknownFields(true);
        if(dataSourcePropertyValues == null){
            Map<String, Object> rpr = new RelaxedPropertyResolver(env, "spring.datasource").getSubProperties(".");
            HashMap<String, Object> values = new HashMap<>(rpr);
            // 排除已经设置的属性
            values.remove("type");
            values.remove("driverClassName");
            values.remove("url");
            values.remove("username");
            values.remove("password");
            dataSourcePropertyValues = new MutablePropertyValues(values);
        }
        dataBinder.bind(dataSourcePropertyValues);
    }
}



二、2.x数据源配置

[注]由于2.x中springboot 官方删除了org.springframework.boot.bind 这个包所以原有配置不再适用 新增Binder类取代

Nacos Java Client serverAddr 多地址负载均衡_mysql_02


properties 文件中这些短杠不要用下划线

Nacos Java Client serverAddr 多地址负载均衡_spring boot_03

<parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-parent</artifactId>
     <version>2.3.7.RELEASE</version>
 </parent>
package com.lxn.eureka.datasource2_x_properties;

import java.lang.annotation.*;

/**
 * @author: ligangan
 * @Description 定义切换数据源的注解
 */
@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface TargetDataSource {
    String name();
}
package com.lxn.eureka.datasource2_x_properties;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.boot.context.properties.bind.Bindable;
import org.springframework.boot.context.properties.bind.Binder;
import org.springframework.boot.context.properties.source.ConfigurationPropertyName;
import org.springframework.boot.context.properties.source.MapConfigurationPropertySource;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.EnvironmentAware;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.core.convert.ConversionService;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.env.Environment;
import org.springframework.core.type.AnnotationMetadata;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 */
public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware {

    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceRegister.class);

    /**
     * 如果配置文件中未指定数据源类型，使用该默认值
     */
    private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.DataSource";
    /**
     * 数据源
     */
    private DataSource defaultDataSource;
    /**
     * 自定义数据源
     */
    private Map<String,DataSource> customDataSources = new HashMap<>();
    /**
     * 公共数据源配置
     */
    private Map<String,Object> commonConfig;
    private Binder binder;

    @Override
    public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry beanDefinitionRegistry) {
        Map<Object,Object> targetDataSources = new HashMap<Object,Object>();
        // 将主数据源添加到更多数据源中
        targetDataSources.put("dataSource",defaultDataSource);
        DynamicDataSourceContextHolder.dataSourceIds.add("dataSource");
        // 添加更多数据源
        targetDataSources.putAll(customDataSources);
        // 创建DynamicDataSource
        GenericBeanDefinition beanDefinition = new GenericBeanDefinition();
        beanDefinition.setBeanClass(DynamicDataSource.class);
        beanDefinition.setSynthetic(true);
        MutablePropertyValues mvp = beanDefinition.getPropertyValues();
        mvp.addPropertyValue("defaultTargetDataSource",defaultDataSource);
        mvp.addPropertyValue("targetDataSources",targetDataSources);
        beanDefinitionRegistry.registerBeanDefinition("dataSource", beanDefinition);
    }

    /**
     * 创建DataSource
     */
    @SuppressWarnings("unchecked")
    public DataSource buildDataSource(Map<String,Object> dsMap) {
        try {
            Object type = dsMap.get("type");
            if(type == null) {
                type = DATASOURCE_TYPE_DEFAULT; // 默认DataSource
            }
            Class<? extends  DataSource> dataSourceType;
            dataSourceType = (Class<? extends DataSource>) Class.forName((String)type);
            String driverClassName = dsMap.get("driverClassName").toString();
            String url = dsMap.get("url").toString();
            String username = dsMap.get("username").toString();
            String password = dsMap.get("password").toString();

            DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url).username(username).password(password).type(dataSourceType);
            return factory.build();
        }catch (ClassNotFoundException e) {
            logger.error("buildDataSource error", e);
        }
        return null;
    }

    /**
     * 加载多数据源
     * @param env
     */
    @Override
    public void setEnvironment(Environment env) {
        // 新增环境传入
        binder = Binder.get(env);
        // 默认数据源配置
        initDefaultDataSource(env);
        // 其它数据源配置
        initCustomDataSource(env);
    }

    /**
     * 初始化主数据源
     * @param env
     */
    private void initDefaultDataSource(Environment env) {
      commonConfig = binder.bind("spring.datasource", Map.class).get();
      // 生成DataSource, 用于注册
      defaultDataSource = buildDataSource(commonConfig);
      // 给DataSource赋值其它公共配置
        dataBinder(defaultDataSource,commonConfig);
    }

    /**
     * 初始化更多数据源
     * @param env
     */
    private void initCustomDataSource(Environment env) {
        Map otherConfig = binder.bind("custom.datasource", Map.class).get();
        String dsPrefixs = otherConfig.get("names").toString();
        for (String dsPrefix : dsPrefixs.split(",")) {
            Map<String, Object> dsMap = binder.bind("custom.datasource."+dsPrefix,Map.class).get();
            HashMap<String, Object> mergeMap = new HashMap<>();
            mergeMap.putAll(commonConfig);
            mergeMap.putAll(dsMap);
            DataSource ds = buildDataSource(mergeMap);
            customDataSources.put(dsPrefix,ds);
            dataBinder(ds, mergeMap);
            DynamicDataSourceContextHolder.dataSourceIds.add(dsPrefix);
        }
    }

   private void dataBinder(DataSource dataSource, Map<String,Object> config){
       MapConfigurationPropertySource source = new MapConfigurationPropertySource(config);
       Binder binder = new Binder(source);
       binder.bind(ConfigurationPropertyName.EMPTY, Bindable.ofInstance(dataSource));
   }
}
package com.lxn.eureka.datasource2_x_properties;

import java.util.ArrayList;
import java.util.List;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 * 判断指定DataSource 当前是否存在
 */
public class DynamicDataSourceContextHolder {

    private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
    public static List<String> dataSourceIds = new ArrayList<>();

    public static void setDataSourceType(String dataSourceType) {
        contextHolder.set(dataSourceType);
    }
    public static String getDataSourceType(){
        return contextHolder.get();
    }
    public static void clearDataSourceType () {
        contextHolder.remove();
    }
    public static boolean containsDataSource(String dataSourceId) {
        return dataSourceIds.contains(dataSourceId);
    }
}
package com.lxn.eureka.datasource2_x_properties;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:59
 * 切换数据源Advice
 */
@Aspect
@Order(-1) // 保证该AOP在@Transactional 之前执行
@Component
public class DynamicDataSourceAspect {
    private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class);

    @Before("@annotation(ds)")
    public void changeDataSource(JoinPoint joinPoint, TargetDataSource ds)  throws Throwable{
        String dsId = ds.name();
        if(!DynamicDataSourceContextHolder.containsDataSource(dsId)){
            logger.error("数据源[{}]不存在，使用默认数据源>{}",ds.name(), joinPoint.getSignature());
        }else{
            logger.debug("Use DataSource: {} > {}",ds.name(), joinPoint.getSignature());
            DynamicDataSourceContextHolder.setDataSourceType(ds.name());
        }
    }
    @After("@annotation(ds)")
    public void restoreDataSource(JoinPoint joinPoint, TargetDataSource ds){
        logger.debug("Use DataSource: {} > {}",ds.name(), joinPoint.getSignature());
        DynamicDataSourceContextHolder.clearDataSourceType();
    }
}
package com.lxn.eureka.datasource2_x_properties;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * @author: ligangan
 * @Date: 2021/3/12
 * @Time: 12:58
 * 动态数据源
 */
public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}



三、1.x 与 2.x 踩坑

  • 2.x中springboot 官方删除了org.springframework.boot.bind 这个包所以原有配置不再适用 新增Binder类取代
  • properties文件中不支持_替换为-
  • 使用注解的方式都是@TargetDataSource (name="")