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。
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spring:
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application:
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name: dynamicDatasource
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datasource:
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test1:
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driver-class-name: com.mysql.jdbc.Driver
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url: jdbc:mysql://127.0.0.1:3306/test1?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
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username: root
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password: 123456
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test2:
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driver-class-name: com.mysql.jdbc.Driver
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url: jdbc:mysql://127.0.0.1:3306/test2?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
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username: root
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password: 123456
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test3:
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driver-class-name: com.mysql.jdbc.Driver
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url: jdbc:mysql://127.0.0.1:3306/test3?serverTimezone=GMT%2B8&characterEncoding=utf-8&useSSL=false
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username: root
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password: 123456
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hikari:
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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
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@Configuration
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public class Test1DataSourceBean {
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@Value("${spring.datasource.test1.driver-class-name}")
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private String test1Driver;
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@Value("${spring.datasource.test1.url}")
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private String test1Url;
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@Value("${spring.datasource.test1.username}")
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private String test1Username;
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@Value("${spring.datasource.test1.password}")
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private String test1Password;
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@Bean(name="test1DataSource")
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public DataSource test1DataSource() throws Exception{
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HikariDataSource dataSource = new HikariDataSource();
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dataSource.setDriverClassName(test1Driver);
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dataSource.setJdbcUrl(test1Url);
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dataSource.setUsername(test1Username);
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dataSource.setPassword(test1Password);
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return dataSource;
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}
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}
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@Configuration
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public class Test2DataSourceBean {
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@Value("${spring.datasource.test2.driver-class-name}")
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private String test2Driver;
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@Value("${spring.datasource.test2.url}")
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private String test2Url;
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@Value("${spring.datasource.test2.username}")
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private String test2Username;
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@Value("${spring.datasource.test2.password}")
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private String test2Password;
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@Bean(name="test2DataSource")
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public DataSource test2DataSource() throws Exception{
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HikariDataSource dataSource = new HikariDataSource();
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dataSource.setDriverClassName(test2Driver);
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dataSource.setJdbcUrl(test2Url);
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dataSource.setUsername(test2Username);
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dataSource.setPassword(test2Password);
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return dataSource;
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}
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}
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@Configuration
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public class Test3DataSourceBean {
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@Value("${spring.datasource.test3.driver-class-name}")
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private String test3Driver;
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@Value("${spring.datasource.test3.url}")
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private String test3Url;
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@Value("${spring.datasource.test3.username}")
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private String test3Username;
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@Value("${spring.datasource.test3.password}")
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private String test3Password;
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@Bean(name="test3DataSource")
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public DataSource test3DataSource() throws Exception{
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HikariDataSource dataSource = new HikariDataSource();
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dataSource.setDriverClassName(test3Driver);
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dataSource.setJdbcUrl(test3Url);
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dataSource.setUsername(test3Username);
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dataSource.setPassword(test3Password);
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return dataSource;
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}
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}
定义一个枚举类管理数据源
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public enum DatabaseType {
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test1("test1", "test1"),
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test2("test2", "test2"),
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test3("test3","test3");
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private String name;
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private String value;
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DatabaseType(String name, String value){
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this.name = name;
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this.value = value;
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}
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public String getName(){
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return name;
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}
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public String getValue(){
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return value;
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}
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}
定义一个线程安全的数据源容器
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public class DatabaseContextHolder {
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private static final ThreadLocal<DatabaseType> contextHolder = new ThreadLocal<>();
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public static void setDatabaseType(DatabaseType type){
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contextHolder.set(type);
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}
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public static DatabaseType getDatabaseType(){
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return contextHolder.get();
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}
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}
定义动态数据源
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public class DynamicDataSource extends AbstractRoutingDataSource{
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protected Object determineCurrentLookupKey() {
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return DatabaseContextHolder.getDatabaseType();
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}
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}
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。
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@Configuration
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@MapperScan(basePackages="cn.test.jichi", sqlSessionFactoryRef="sessionFactory")
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public class MybatisConfig {
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/**
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* @Description:设置动态数据源
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*/
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@Bean(name="dynamicDataSource")
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@Primary
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public DynamicDataSource DataSource(
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@Qualifier("test1DataSource") DataSource test1DataSource,
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@Qualifier("test2DataSource") DataSource test2DataSource,
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@Qualifier("test3DataSource") DataSource test3DataSource){
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Map<Object, Object> targetDataSource = new HashMap<>();
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targetDataSource.put(DatabaseType.test1, test1DataSource);
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targetDataSource.put(DatabaseType.test2, test2DataSource);
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targetDataSource.put(DatabaseType.test3, test3DataSource);
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DynamicDataSource dataSource = new DynamicDataSource();
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dataSource.setTargetDataSources(targetDataSource);
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dataSource.setDefaultTargetDataSource(test1DataSource);
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return dataSource;
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}
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/**
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* @Description:根据动态数据源创建sessionFactory
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*/
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@Bean(name="sessionFactory")
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public SqlSessionFactory sessionFactory(
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@Qualifier("test1DataSource") DataSource test1DataSource,
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@Qualifier("test2DataSource") DataSource test2DataSource,
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@Qualifier("test3DataSource") DataSource test3DataSource) throws Exception{
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SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
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//构造方法，解决动态数据源循环依赖问题。
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sessionFactoryBean.setDataSource(this.DataSource(test1DataSource,test2DataSource, test3DataSource));
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return sessionFactoryBean.getObject();
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}
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}
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package cn.chinaunicom.sdsi.utils;
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import cn.chinaunicom.sdsi.config.dynamicDataSourceConfig.DatabaseContextHolder;
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import cn.chinaunicom.sdsi.config.dynamicDataSourceConfig.DatabaseType;
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/**
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* @Description:封装数据源选择
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*/
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public class DynamicDataSourceUtils {
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public static void chooseBasicDataSource(){
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DatabaseContextHolder.setDatabaseType(DatabaseType.basic);
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}
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public static void chooseBranchDataSource(){
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DatabaseContextHolder.setDatabaseType(DatabaseType.branch);
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}
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}
提供一个示例
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public void testDymnaicDatasource(){
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//不切换数据源默认是自己的。
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System.out.println("-----默认数据源");
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DemoEntity totalCount = demoMapper.getTotalCount();
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String nameCount1 = totalCount.getNameCount();
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String ageCount2 = totalCount.getAgeCount();
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System.out.println("nameCount:"+nameCount1);
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System.out.println("ageCount:"+ageCount2);
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//数据源切换为branch
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System.out.println("-----数据源为test2");
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DynamicDataSourceUtils.chooseBranchDataSource();
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Integer nameCount = demoMapper.getNameCount();
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Integer ageCount = demoMapper.getAgeCount();
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System.out.println("nameCount:"+nameCount);
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System.out.println("ageCount:"+ageCount);
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//数据源为basic
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System.out.println("-----数据源为test3");
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DynamicDataSourceUtils.chooseBasicDataSource();
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Integer ageCount1 = demoMapper.getAgeCount();
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System.out.println("ageCount:"+ageCount1);
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}
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。
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