I am trying to use Spring's Autowire but the Bean instantiation fails if I don't explicitly define the Bean with an @Bean annotation.
Here is a sample code:
@Component
public class Bar {
}
@Component
public class Foo {
private final Bar bar;
@Autowired
public Foo(Bar bar) {
this.bar = bar;
}
}
@Configuration
@ComponentScan(basePackages = {"com"})
public class StringTest {
public static void main(String[] args) {
ApplicationContext ctx = new AnnotationConfigApplicationContext(TestConfig.class);
Foo foo = ctx.getBean(Foo.class);
}
}
@Configuration
public class TestConfig {
@Bean
public Foo foo(Bar bar) {
return new Foo(bar);
}
@Bean
public Bar bar() {
return new Bar();
}
}
This is a working version, but if I comment out the bean definitions in the TestConfig class spring fails to instantiate Foo, and I get this excepiton:
> Exception in thread "main"
> org.springframework.beans.factory.NoSuchBeanDefinitionException: No
> qualifying bean of type 'com.test.Foo' available at
> org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:347)
> at
> org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:334)
> at
> org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1107)
> at com.test.StringTest.main(StringTest.java:15)
The Bean I am trying to create is a concrete class, so I thought spring should automatically find it.
Should I always explicitly define the beans in a configuration class?
