This example shows how to implement ImportSelector for configuration selection.
In this example we are going to select @Configuration classes, based on a System property value.
Example
ImportSelector implementation
public class MyImportSelector implements ImportSelector {
@Override
public String[] selectImports(AnnotationMetadata importingClassMetadata) {
String prop = System.getProperty("myProp");
if ("someValue".equals(prop)) {
return new String[]{MyConfig1.class.getName()};
} else {
return new String[]{MyConfig2.class.getName()};
}
}
}
MyConfig1
@Configuration
public class MyConfig1 {
@Bean
AppBean appBean() {
return new AppBean("from config 1");
}
}
MyConfig2
@Configuration
public class MyConfig2 {
@Bean
AppBean appBean() {
return new AppBean("from config 2");
}
}
AppBean
public class AppBean {
private String message;
public AppBean(String message) {
this.message = message;
}
public String getMessage() {
return message;
}
}
MainConfig
@Configuration
@Import(MyImportSelector.class)
public class MainConfig {
@Bean
ClientBean clientBean() {
return new ClientBean();
}
}
ClientBean
public class ClientBean {
@Autowired
private AppBean appBean;
public void doSomething() {
System.out.println(appBean.getMessage());
}
}
Main class
public class ImportSelectorExample {
public static void main(String[] args) {
System.setProperty("myProp", "someValue");
ApplicationContext context =
new AnnotationConfigApplicationContext(
MainConfig.class);
ClientBean bean = context.getBean(ClientBean.class);
bean.doSomething();
}
}
Outputfrom config 1
Example ProjectDependencies and Technologies Used: - spring-context 6.2.12 (Spring Context)
Version Compatibility: 3.2.3.RELEASE - 6.2.12 Version compatibilities of spring-context with this example: Versions in green have been tested.
- JDK 25
- Maven 3.9.11
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