Spingboot Jpa+Mybatis+ 多数据源持久层写法分享

前景

吐血教训,打死我都不用 JPA 了,写一些复杂查询非常不友好,也就是因为这样,导致自己开发项目的临近结尾卡了好几天写不出来,怎么办呢?换框架来写不可能,时间不允许,于是只能把 mybatis 当作第二个数据源持久层放到我的框架中

创建一个全局配置数据源的类文件

package com.center.config.admin;
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;


/**
 * 数据源的配置
 * @author javashishijieshangzuihaodeyuyan
 */
@Configuration
public class DataSourceConfig {

    //第一数据源 --  jpa
    @Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @ConfigurationProperties(prefix = "spring.primary.datasource")
    @Primary
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }
    //第二数据源 -- mybatis
    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.secondary.datasource")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }

}

新建第一数据源的配置文件(JPA)

这个类的目的就是去读取 JPA 的那些持久层文件,
也就是我们要配置好 model,dao
我会代码标注!

package com.center.config.admin;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
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.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.Map;

/**
 * jpa数据源一
 */
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactoryPrimary",
        transactionManagerRef = "transactionManagerPrimary",
        basePackages = {
                "com.center.dao.admin"
        }) //设置Repository所在位置

public class PrimaryConfig {

    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;

    @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.center.entity.admin"
                ) //设置实体类所在位置
                .persistenceUnit("primaryPersistenceUnit")
                .build();
    }

    @Autowired
    private JpaProperties jpaProperties;
    @Autowired
    private HibernateProperties hibernateProperties;
    private Map<String, Object> getVendorProperties() {

        return hibernateProperties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings());
    }
    @Primary
    @Bean(name = "transactionManagerPrimary")
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    }
}

新建第二数据源的配置文件(Mybatis)

package com.center.config.admin;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;


/**
 * mybatis
 */
@Configuration
@MapperScan(basePackages = "com.center.mapper",
        sqlSessionFactoryRef = "secondarySqlSessionFactory")
public class SecondaryDataConfig {

    @Bean(name = "secondarySqlSessionFactory")
    public SqlSessionFactory SecondarySqlSessionFactory(@Qualifier("secondaryDataSource") DataSource datasource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(datasource);
        bean.setMapperLocations(
                new PathMatchingResourcePatternResolver()
                        .getResources("classpath*:/mapper/*.xml"));
        bean.setTypeAliasesPackage("com.center.entity.admin.mountain");
        return bean.getObject();
    }

    @Primary
    @Bean("SecondarySqlSessionTemplate")
    public SqlSessionTemplate SecondarySqlsessiontemplate(
            @Qualifier("secondarySqlSessionFactory") SqlSessionFactory sessionfactory) {
        return new SqlSessionTemplate(sessionfactory);
    }

    //用来作为数据库事务回滚的限定词
    //@Transactional(rollbackFor = OAPMException.class, value = "transactionManagerSecondary")
    // 创建事务管理器
    @Bean("secondTransactionMangerMybatis")
    public DataSourceTransactionManager secondTransactionManger(@Qualifier("secondaryDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

通过这样的配置,接下来只需要在对应路径下写不一样的持久层框架的代码即可解决,复杂查询交给 mybatis!,简单查询 JPA 来搞定!