SpringBoot Mybatis动态数据源切换方案实现过程

背景

最近让我做一个大数据的系统，分析了一下，麻烦的地方就是多数据源切换抽取数据。考虑到可以跨服务器跨数据库抽数，再整理数据，就配置了这个动态数据源的解决方案。在此分享给大家。

实现方案

数据库配置文件

我们项目使用的是yml形式的配置文件，采用的是hikari的数据库连接池。第一步我们自然是配置多个数据库源头。
我们找到spring的datasource，在下方配置三个数据源。

spring:
 application:
 name: dynamicDatasource
 datasource:
 test1:
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://127.0.0.1:3306/test1?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
  username: root
  password: 123456
 test2:
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://127.0.0.1:3306/test2?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
  username: root
  password: 123456
 test3:
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://127.0.0.1:3306/test3?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
  username: root
  password: 123456
 hikari:
  leak-detection-threshold: 2000

定义数据源实体类

我们可以建立个datasourceBean文件夹专门管理数据源的实体类。

我们这里要建立三个实体类。分别对应test1，test2，test3

@Configuration
public class Test1DataSourceBean {

 @Value("${spring.datasource.test1.driver-class-name}")
 private String test1Driver;

 @Value("${spring.datasource.test1.url}")
 private String test1Url;

 @Value("${spring.datasource.test1.username}")
 private String test1Username;

 @Value("${spring.datasource.test1.password}")
 private String test1Password;

 @Bean(name="test1DataSource")
 public DataSource test1DataSource() throws Exception{
  HikariDataSource dataSource = new HikariDataSource();
  dataSource.setDriverClassName(test1Driver);
  dataSource.setJdbcUrl(test1Url);
  dataSource.setUsername(test1Username);
  dataSource.setPassword(test1Password);
  return dataSource;
 }
}

@Configuration
public class Test2DataSourceBean {

 @Value("${spring.datasource.test2.driver-class-name}")
 private String test2Driver;

 @Value("${spring.datasource.test2.url}")
 private String test2Url;

 @Value("${spring.datasource.test2.username}")
 private String test2Username;

 @Value("${spring.datasource.test2.password}")
 private String test2Password;

 @Bean(name="test2DataSource")
 public DataSource test2DataSource() throws Exception{
  HikariDataSource dataSource = new HikariDataSource();
  dataSource.setDriverClassName(test2Driver);
  dataSource.setJdbcUrl(test2Url);
  dataSource.setUsername(test2Username);
  dataSource.setPassword(test2Password);
  return dataSource;
 }
}

@Configuration
public class Test3DataSourceBean {

 @Value("${spring.datasource.test3.driver-class-name}")
 private String test3Driver;

 @Value("${spring.datasource.test3.url}")
 private String test3Url;

 @Value("${spring.datasource.test3.username}")
 private String test3Username;

 @Value("${spring.datasource.test3.password}")
 private String test3Password;

 @Bean(name="test3DataSource")
 public DataSource test3DataSource() throws Exception{
  HikariDataSource dataSource = new HikariDataSource();
  dataSource.setDriverClassName(test3Driver);
  dataSource.setJdbcUrl(test3Url);
  dataSource.setUsername(test3Username);
  dataSource.setPassword(test3Password);
  return dataSource;
 }
}

定义一个枚举类管理数据源

public enum DatabaseType {

 test1("test1", "test1"),
 test2("test2", "test2"),
 test3("test3","test3");

 private String name;
 private String value;

 DatabaseType(String name, String value){
  this.name = name;
  this.value = value;
 }

 public String getName(){
  return name;
 }

 public String getValue(){
  return value;
 }
}

定义一个线程安全的数据源容器

public class DatabaseContextHolder {
 private static final ThreadLocal<DatabaseType> contextHolder = new ThreadLocal<>();
 public static void setDatabaseType(DatabaseType type){
  contextHolder.set(type);
 }
 public static DatabaseType getDatabaseType(){
  return contextHolder.get();
 }
}

定义动态数据源

public class DynamicDataSource extends AbstractRoutingDataSource{
 protected Object determineCurrentLookupKey() {
  return DatabaseContextHolder.getDatabaseType();
 }
}

mybatis配置类

网上的很多文章配置出来都会产生数据源循环依赖的问题，这里解决了这个问题。

@Configuration
@MapperScan(basePackages="cn.test.jichi", sqlSessionFactoryRef="sessionFactory")
public class MybatisConfig {

 /**
  * @Description:设置动态数据源
  */
 @Bean(name="dynamicDataSource")
 @Primary
 public DynamicDataSource DataSource(
   @Qualifier("test1DataSource") DataSource test1DataSource,
   @Qualifier("test2DataSource") DataSource test2DataSource,
   @Qualifier("test3DataSource") DataSource test3DataSource){
  Map<Object, Object> targetDataSource = new HashMap<>();
  targetDataSource.put(DatabaseType.test1, test1DataSource);
  targetDataSource.put(DatabaseType.test2, test2DataSource);
  targetDataSource.put(DatabaseType.test3, test3DataSource);
  DynamicDataSource dataSource = new DynamicDataSource();
  dataSource.setTargetDataSources(targetDataSource);
  dataSource.setDefaultTargetDataSource(test1DataSource);
  return dataSource;
 }

 /**
  * @Description:根据动态数据源创建sessionFactory
  */
 @Bean(name="sessionFactory")
 public SqlSessionFactory sessionFactory(
   @Qualifier("test1DataSource") DataSource test1DataSource,
   @Qualifier("test2DataSource") DataSource test2DataSource,
   @Qualifier("test3DataSource") DataSource test3DataSource) throws Exception{
  SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
  //构造方法，解决动态数据源循环依赖问题。
  sessionFactoryBean.setDataSource(this.DataSource(test1DataSource,test2DataSource, test3DataSource));
  return sessionFactoryBean.getObject();
 }
}

示例

 public void testDymnaicDatasource(){
  //不切换数据源默认是自己的。
  System.out.println("-----默认数据源");
  DemoEntity totalCount = demoMapper.getTotalCount();
  String nameCount1 = totalCount.getNameCount();
  String ageCount2 = totalCount.getAgeCount();
  System.out.println("nameCount:"+nameCount1);
  System.out.println("ageCount:"+ageCount2);
  //数据源切换为branch
  System.out.println("-----数据源为test2");
  DynamicDataSourceUtils.chooseBranchDataSource();
  Integer nameCount = demoMapper.getNameCount();
  Integer ageCount = demoMapper.getAgeCount();
  System.out.println("nameCount:"+nameCount);
  System.out.println("ageCount:"+ageCount);
  //数据源为basic
  System.out.println("-----数据源为test3");
  DynamicDataSourceUtils.chooseBasicDataSource();
  Integer ageCount1 = demoMapper.getAgeCount();
  System.out.println("ageCount:"+ageCount1);

 }

总结

至此实现了多数据源的动态切换。可以在同一个方法里面进行操作多个数据源。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。