当Spring Boot和Mybatis项目中有多个数据源时，出现NoUniqueBeanDefinitionException [英] NoUniqueBeanDefinitionException when multiple datasources in Spring Boot and Mybatis project

问题描述

在Spring Boot和Mybatis项目中配置多个数据源时，发生以下异常:

When configuring multiple datasources in Spring Boot and Mybatis project, following Exception occurs:

org.springframework.beans.factory.NoUniqueBeanDefinitionException:否 类型的合格豆 'org.springframework.transaction.PlatformTransactionManager' 可用:预期的单个匹配bean，但发现2: primaryTx，secondTx在 org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1041) 〜[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:345) 〜[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:340) 〜[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.transaction.interceptor.TransactionAspectSupport.determineTransactionManager(TransactionAspectSupport.java:384) 〜[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:272) 〜[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) 〜[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 〜[spring-aop-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) 〜[spring-aop-4.3.13.RELEASE.jar:4.3.13.RELEASE]在 com.sun.proxy.$ Proxy86.findByDomain(未知来源)〜[na:na]

org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.transaction.PlatformTransactionManager' available: expected single matching bean but found 2: primaryTx,secondTx at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1041) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:345) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:340) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.transaction.interceptor.TransactionAspectSupport.determineTransactionManager(TransactionAspectSupport.java:384) ~[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:272) ~[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.13.RELEASE.jar:4.3.13.RELEASE] at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.13.RELEASE.jar:4.3.13.RELEASE] at com.sun.proxy.$Proxy86.findByDomain(Unknown Source) ~[na:na]

项目开始

@SpringBootApplication( exclude = {
        DataSourceAutoConfiguration.class, 
        DataSourceTransactionManagerAutoConfiguration.class
})
@EnableTransactionManagement
public class BookSystemApplication {
}

数据源配置

@Configuration
public class DataSourceConfig {
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.second")
    public DataSource secondDataSource() {
        return DataSourceBuilder.create().build();
    }
}

交易

@Configuration
public class TransactionConfig {
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primary;

    @Autowired
    @Qualifier("secondDataSource")
    private DataSource second;

    @Bean(name="primaryTx")
    public PlatformTransactionManager primaryTransaction() {
        return new DataSourceTransactionManager(primary);
    }

    @Bean(name="secondTx")
    public PlatformTransactionManager secondTransaction() {
        return new DataSourceTransactionManager(second);
    }
}

推荐答案

这里的问题是，您要将两个beans定义为datasource，将两个bean定义为TransactionManager，但是没有指定其中一个是primary，将不起作用，因为 Spring需要一个datasource bean和一个TransactionManager bean被定义为主豆 ，如果.

The problem here is that you are defining two beans as datasource and two beans as TransactionManager but you didn't specify which one of them is the primary one, this won't work because Spring needs one datasource bean and one TransactionManager bean to be defined as primary if more than one are defined.

您应该在这里定义一个数据源beans和一个TransactionManager beans为Primary，这样Spring才能正确运行，您需要使用 @Primary注释.

What you should do here is to define, one of your datasources beans and one of your TransactionManager beans as Primary, so that Spring can run correctly, to do so you will need to use @Primary annotation.

@Bean(name = "primaryDataSource")
@Primary
@ConfigurationProperties(prefix = "spring.datasource.primary")
public DataSource primaryDataSource() {
    return DataSourceBuilder.create().build();
}

请参考

Please refer to the Spring's Configure two datasources section from the Documentation.

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