Spring with MyBatis: expected single bean matching, but 2 found

Question

I use Spring with MyBatis and it works very well for a single database. I ran into difficulties when trying to add another database (see reproducible example on Github ).

I am using Java Spring configuration (i.e. not XML). Most of the examples I've seen show how to achieve this using XML.

I have two data configuration classes (A and B):

@Configuration
@MapperScan("io.woolford.database.mapper")
public class DataConfigDatabaseA {

    @Bean(name="dataSourceA")
    public DataSource dataSourceA() throws SQLException {
        SimpleDriverDataSource dataSource = new SimpleDriverDataSource();
        dataSource.setDriver(new com.mysql.jdbc.Driver());
        dataSource.setUrl("jdbc:mysql://" + dbHostA + "/" + dbDatabaseA);
        dataSource.setUsername(dbUserA);
        dataSource.setPassword(dbPasswordA);
        return dataSource;
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSourceA());
        return sessionFactory.getObject();
    }
}

Two cartographers and a service that performs automatic machines:

@Service
public class DbService {

    @Autowired
    private DbMapperA dbMapperA;

    @Autowired
    private DbMapperB dbMapperB;

    public List<Record> getDabaseARecords(){
        return dbMapperA.getDatabaseARecords();
    }

    public List<Record> getDabaseBRecords(){
        return dbMapperB.getDatabaseBRecords();
    }

}

The application does not start:

Error creating bean with name 'dataSourceInitializer': 
  Invocation of init method failed; nested exception is 
    org.springframework.beans.factory.NoUniqueBeanDefinitionException: 
      No qualifying bean of type [javax.sql.DataSource] is defined: 
        expected single matching bean but found 2: dataSourceB,dataSourceA

I read that you can use annotation @Qualifierto disambiguate autoinstall, although I was not sure where to add it.

Do you see me wrong?

Answer 1

:

src/main/java/io/woolford/database/mapper/a/DbMapperA.java
src/main/java/io/woolford/database/mapper/c/DbMapperB.java

DataConfig, . @MapperScan expected single matching bean but found 2.

@Configuration
@MapperScan(value = {"io.woolford.database.mapper.a"}, sqlSessionFactoryRef="sqlSessionFactoryA")
public class DataConfigDatabaseA {

@Primary beans DataConfig:

@Bean(name="dataSourceA")
@Primary
public DataSource dataSourceA() throws SQLException {
    ...
}

@Bean(name="sqlSessionFactoryA")
@Primary
public SqlSessionFactory sqlSessionFactoryA() throws Exception {
    ...
}

, . , . @Qualifier @EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class}) @eduardlofitskyi @GeminiKeith, .

, , , , : https://github.com/alexwoolford/mybatis-spring-multiple-mysql-reproducible-example

Answer 2

, , DataSourceAutoConfiguration @EnableAutoConfiguration(excludes = {DataSourceAutoConfiguration.class}) , @SpringBootApplication. SqlSessionFactory DataSource. DataSourceTransactionManager, .

DataSourceAutoConfiguration, spring framework @Autowired DataSource, .

, DataSourceAutoConfiguration .

:

@SpringBootApplication
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
public class YourApplication implements CommandLineRunner {
    public static void main (String... args) {
        SpringApplication.run(YourApplication.class, args);
    }
}

, bean, :

package xyz.cloorc.boot.mybatis;

import org.apache.commons.dbcp.BasicDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Repository;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.sql.DataSource;

@Configuration
public class SimpleTest {

    private DataSource dsA;
    private DataSource dsB;

    @Bean(name = "dataSourceA")
    public DataSource getDataSourceA() {
        return dsA != null ? dsA : (dsA = new BasicDataSource());
    }

    @Bean(name = "dataSourceB")
    public DataSource getDataSourceB() {
        return dsB != null ? dsB : (dsB = new BasicDataSource());
    }

    @Bean(name = "sqlSessionFactoryA")
    public SqlSessionFactory getSqlSessionFactoryA() throws Exception {
        // set DataSource to dsA
        return new SqlSessionFactoryBean().getObject();
    }

    @Bean(name = "sqlSessionFactoryB")
    public SqlSessionFactory getSqlSessionFactoryB() throws Exception {
        // set DataSource to dsB
        return new SqlSessionFactoryBean().getObject();
    }
}

@Repository
public class SimpleDao extends SqlSessionDaoSupport {

    @Resource(name = "sqlSessionFactoryA")
    SqlSessionFactory factory;

    @PostConstruct
    public void init() {
        setSqlSessionFactory(factory);
    }

    @Override
    public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
        super.setSqlSessionFactory(sqlSessionFactory);
    }

    public <T> T get (Object id) {
        return super.getSqlSession().selectOne("sql statement", "sql parameters");
    }
}

Answer 3

@Qualifier

, beans Spring. autwire beans, Spring , bean

@Qualifier - . @Autowired @Inject , , bean .

, DbService :

    @Service
    public class DbService {

    @Autowired
    @Qualifier("dataSourceA")
    private DbMapperA dbMapperA;

    @Autowired
    @Qualifier("dataSourceB")
    private DbMapperB dbMapperB;

    public List<Record> getDabaseARecords(){
        return dbMapperA.getDatabaseARecords();
    }

    public List<Record> getDabaseBRecords(){
        return dbMapperB.getDatabaseBRecords();
    }

}

Answer 4

I had the same problem, and I could not start the Spring boot application, and by renaming the intruder class and all the layers it was dealing with, it is strange that the application started successfully.

I have classes UOMService, UOMServiceImpl UOMRepositoryand UOMRepositoryImpl. I renamed them UOMService, UOMServiceImpl, UOMRepositoryand UOMRepositoryImpland it solved the problem!