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Because I have to work with a legacy application, I want to use beans from a separate Spring context.

I create this separate Spring context with an XML beans definition like this:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="some.different.package"/>

    <bean id="connectionUrlFactory" class="my.ConnectionUrlFactory">
        <property name="dbServer" value="server.url.com"/>
        <property name="dbDatabasename" value="database"/>
        <property name="dbClientName" value="client"/>
    </bean>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.sybase.jdbc4.jdbc.SybDriver"/>
        <property name="url" ref="connectionUrlFactory"/>
        <property name="username" value="user"/>
        <property name="password" value="password"/>
    </bean>

</beans>

In my own, "outer" Spring Boot application, I have a context @Configuration like this:

@Configuration
class Configuration {

    private final ApplicationContext applicationContext;

    Configuration() {
        applicationContext = new ClassPathXmlApplicationContext("beans.xml");
    }

    @Bean
    DaoSybaseImpl sybaseDao() {
        return applicationContext.getBean(DaoSybaseImpl.class);
    }

    @Bean
    DataSource sybaseDataSource() {
        return applicationContext.getBean(DataSource.class);
    }

}

However, when I run the application, I get this error:

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'sybaseDao': Unsatisfied dependency expressed through method 'setDataSource' parameter 0; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'javax.sql.DataSource' available: expected single matching bean but found 2: postgresDataSource,sybaseDataSource
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.resolveMethodArguments(AutowiredAnnotationBeanPostProcessor.java:768)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:720)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1413)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1380)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887)
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791)
    ... 125 more
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'javax.sql.DataSource' available: expected single matching bean but found 2: postgresDataSource,sybaseDataSource
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveNotUnique(DependencyDescriptor.java:220)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1358)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.resolveMethodArguments(AutowiredAnnotationBeanPostProcessor.java:760)
    ... 140 more

When I remove sybaseDataSource from my @Configuration, the error disappears (my application then doesn't start because it's missing sybaseDataSource).

It seems that the legacy ClassPathXmlApplicationContext does know of my "outer" Spring Boot context. How can this be?

Harold L. Brown
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  • This is just wrong. Ditch your `Configuration` class and add `@IMportResource` on your `@SpringBootApplication` annotated class. This will make your xml config part of the normal configuration. After that you can move beans from the xml to either java or use auto configuration (like for the datasource). – M. Deinum May 28 '21 at 05:45
  • @M.Deinum I know that this is not ideal. But because of how the legacy context is constructed I can't move anything together. I need two different configurations of the legacy context. – Harold L. Brown May 28 '21 at 05:53
  • This simply won't work, as stated you should use `@ImportResource` – M. Deinum May 28 '21 at 07:43

1 Answers1

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I have now removed the "outer" Spring application. With plain Java code I can load the other context without interference.

Harold L. Brown
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