springboot--jpa 配置多数据库

Love The Way You Lie 2023-06-25 04:33 23阅读 0赞

使用spring boot jpa 配置多数据源

由于项目整合 以前的功能 但是以前功能存储的数据库是另一个数据库

这两天搜索了一下 遇见了许多坑 在这里记录一下

首先附上我的项目结构  
![在这里插入图片描述][20191225172732861.png]  
可能有些乱 忘见谅。

pom.xml(把数据库的依赖引入)

<dependency>
                <groupId>org.mariadb.jdbc</groupId>
                <artifactId>mariadb-java-client</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>com.microsoft.sqlserver</groupId>
                <artifactId>mssql-jdbc</artifactId>
                <scope>runtime</scope>
            </dependency>

修改yml配置文件

spring:
      datasource:
      #主数据库 
        primary:  #名字可以自定
          driver-class-name: org.mariadb.jdbc.Driver
          jdbc-url: jdbc:mariadb://xxx/xxx?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai
          username: 123
          password: 123
          #从数据库
        secondary: #名字可以自定
          driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
          jdbc-url: jdbc:sqlserver://www.xx.com:xx/xx?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=Asia/Shanghai
          username: 123
          password: 123
    
      jpa:
        hibernate:
        	#方言
          primary-dialect: org.hibernate.dialect.MySQL5InnoDBDialect
          secondary-dialect: org.hibernate.dialect.SQLServerDialect
            #ddl-auto: validate
            #    create 启动时删数据库中的表，然后创建，退出时不删除数据表
            #    create-drop 启动时删数据库中的表，然后创建，退出时删除数据表 如果表不存在报错
            #    update 如果启动时表格式不一致则更新表，原有数据保留
            #    validate 项目启动表结构进行校验 如果不一致则报错
        show-sql: true

然后需要配置类  
DataSourceConfig–配置数据源

import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.boot.context.properties.ConfigurationProperties;
    import org.springframework.boot.jdbc.DataSourceBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    
    import javax.sql.DataSource;
    
    /** * 读取application.yml配置的两个数据源，并将其注入到Spring的IOC容器中 */
    @Configuration //SpringBoot启动将该类作为配置类，同配置文件一起加载
    public class DataSourceConfig { 
        //将该实体注入到IOC容器中
        @Bean(name = "primaryDataSource")
        //指定数据源名称，与Bean中的name属性原理相同，主要是为了确保注入成功
        @Qualifier("primaryDataSource")
        //指定主数据源
        @Primary
        //将配置文件中的数据源读取进到方法中，进行build
        @ConfigurationProperties(prefix = "spring.datasource.primary")
        public DataSource primaryDataSource() { 
            return DataSourceBuilder.create().build();
        }
    
        //将该实体注入到IOC容器中
        @Bean(name = "secondaryDataSource")
        //指定数据源名称，与Bean中的name属性原理相同，主要是为了确保注入成功
        @Qualifier("secondaryDataSource")
        //将配置文件中的数据源读取进到方法中，进行build
        @ConfigurationProperties(prefix = "spring.datasource.secondary")
        public DataSource secondaryDataSource() { 
            return DataSourceBuilder.create().build();
        }
    }

然后是配置主数据库  
PrimaryConfig

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
    import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
    import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
    import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import org.springframework.core.env.Environment;
    import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
    import org.springframework.orm.jpa.JpaTransactionManager;
    import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
    import org.springframework.transaction.PlatformTransactionManager;
    import org.springframework.transaction.annotation.EnableTransactionManagement;
    
    import javax.annotation.Resource;
    import javax.persistence.EntityManager;
    import javax.sql.DataSource;
    import java.util.HashMap;
    import java.util.Map;
    
    /** * 主数据源 */
    @Configuration
    @EnableTransactionManagement
    @EnableJpaRepositories(
            entityManagerFactoryRef = "entityManagerFactoryPrimary",
            transactionManagerRef = "transactionManagerPrimary",
            basePackages = { "com.xx.mysql.dao"})    // 指定该数据源操作的DAO接口包
    public class PrimaryConfig { 
        @Autowired
        @Qualifier("primaryDataSource")
        private DataSource primaryDataSource;
    
        @Value("${spring.jpa.hibernate.primary-dialect}")
        private String primaryDialect;//获取方言
    
        @Primary
        @Bean(name = "entityManagerPrimary")
        public EntityManager entityManager(EntityManagerFactoryBuilder builder) { 
            return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
        }
    
        @Primary
        @Bean(name = "entityManagerFactoryPrimary")
        public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) { 
            return builder
                    .dataSource(primaryDataSource)
                    .properties(getVendorProperties())
                    .packages("com.xx.mysql.pojo")         //设置实体类所在位置
                    .persistenceUnit("primaryPersistenceUnit")
                    .build();
        }
    
        @Autowired
        private JpaProperties jpaProperties;
        @Autowired
        private HibernateProperties hibernateProperties;
    
        private Map getVendorProperties() { 
          
            Map<String,String> map = new HashMap<>();
            map.put("hibernate.dialect",primaryDialect);// 设置对应的数据库方言
            map.put("hibernate.ddl-auto","validate");//项目启动表结构进行校验 如果不一致则报错
            jpaProperties.setProperties(map);
            return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
            // return jpaProperties.getHibernateProperties(new HibernateSettings());
        }
    
    
    
        @Primary
        @Bean(name = "transactionManagerPrimary")
        public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) { 
            return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
        }
    
    }

**由于我使用的版本是springboot 2.1 在这里jpaProperties 没有了getHibernateProperties方法！！！**

然后是从数据库  
SecondaryConfig

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Qualifier;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
    import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
    import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
    import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import org.springframework.core.env.Environment;
    import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
    import org.springframework.orm.jpa.JpaTransactionManager;
    import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
    import org.springframework.transaction.PlatformTransactionManager;
    import org.springframework.transaction.annotation.EnableTransactionManagement;
    
    import javax.persistence.EntityManager;
    import javax.sql.DataSource;
    import java.util.HashMap;
    import java.util.Map;
    
    /** * 从数据源 */
    @Configuration
    @EnableTransactionManagement
    @EnableJpaRepositories(
            entityManagerFactoryRef = "entityManagerFactorySecondary",
            transactionManagerRef = "transactionManagerSecondary",
            basePackages = { "com.xx.sqlServer.dao"}) //设置DAO接口层所在包位置
    public class SecondaryConfig { 
        @Autowired
        @Qualifier("secondaryDataSource")
        private DataSource secondaryDataSource;
    
        @Value("${spring.jpa.hibernate.secondary-dialect}")
        private String secondaryDialect;//获取方言
    
        @Bean(name = "entityManagerSecondary")
        public EntityManager entityManager(EntityManagerFactoryBuilder builder) { 
            return entityManagerFactorySecondary(builder).getObject().createEntityManager();
        }
    
        @Bean(name = "entityManagerFactorySecondary")
        public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) { 
            return builder
                    .dataSource(secondaryDataSource)
                    .properties(getVendorProperties())
                    .packages("com.xx.sqlServer.pojo")        //设置实体类所在包的位置
                    .persistenceUnit("primaryPersistenceUnit")
                    .build();
        }
    
        @Autowired
        private JpaProperties jpaProperties;
    
        @Autowired
        private HibernateProperties hibernateProperties;
    
        private Map getVendorProperties() { 
            Map<String,String> map = new HashMap<>();
            map.put("hibernate.dialect",secondaryDialect);
            map.put("hibernate.ddl-auto","validate");
            jpaProperties.setProperties(map);
            return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
        }
    
    
        @Bean(name = "transactionManagerSecondary")
        PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) { 
            return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
        }
    
    }

这样就配置好了 ！！！

引用的时候只需要引入对应的dao层接口 即可使用不同的数据库！

[20191225172732861.png]: https://img-blog.csdnimg.cn/20191225172732861.png