spring mybatis circular reference

摘要: Error creating bean with name 'ＸＸＸ': Requested bean is currently in creation: Is there an unresolvable circular reference?; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException:

如果把MapperScan单独配置，就不会有警告

DataSource，SqlSessionFactory，MapperScan有依赖关系．

如果把MapperScan单独配置，就不会有警告，例如：

code：

DataSource:

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Primary;

import javax.sql.DataSource;

@Configuration

public class DataSourceConfig {

    @ConfigurationProperties("spring.datasource.druid")

    @Bean

    public DataSource equipDataSource() {

        return DruidDataSourceBuilder.create().build();

    }

}

SqlSessionFactory:

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionFactoryBean;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import javax.sql.DataSource;

@SuppressWarnings("SpringJavaAutowiringInspection")

@Configuration

public class MyBatisConfig {

    @Bean

    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {

        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();

        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();

        factoryBean.setDataSource(dataSource);

        factoryBean.setTypeAliasesPackage("com.app.domain.entity");// 指定基包

        factoryBean.setMapperLocations(resolver.getResources("classpath:mapper/**/*.xml"));//

        return factoryBean.getObject();

    }

}

MapperScannerConfigurer

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import tk.mybatis.mapper.common.BaseMapper;

import tk.mybatis.spring.mapper.MapperScannerConfigurer;

import java.util.Properties;

@Configuration

public class MapperConfig {

    @Bean

    public MapperScannerConfigurer mapperScannerConfigurer() {

        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();

        mapperScannerConfigurer.setBasePackage("com.app.domain.mapper");

        Properties properties = new Properties();

        // 这里要特别注意，不要把BaseMapper放到 basePackage 中，也就是不能同其他Mapper一样被扫描到。

        properties.setProperty("notEmpty", "false");

        properties.setProperty("IDENTITY", "MYSQL");

        mapperScannerConfigurer.setProperties(properties);

        mapperScannerConfigurer.setMarkerInterface(BaseMapper.class);

        return mapperScannerConfigurer;

    }

}

https://my.oschina.net/doctor2014/blog/386431

Requested bean is currently in creation: Is there an unresolvable circular reference?

getBean的时候由于bean之间存在循环依赖出现类似的错误，先做一个简单实验模拟一下这个异常出现的原因：

bean在初始化的同时会初始化相应的属性（byName），a在初始化的时候会创建a.b，a.b在初始化的时候会创建a.b.a，形成了一个环，所以在AbstractBeanFactory.doGetBean（这里会出现递归调用） 时候 ，走到：