Why does springboot refresh the bean only once when I remove bean and add another bean? - spring-boot

Question

I have a requirement to remove the corresponding Bean and then add another Bean, but I find that springboot only refreshes the injected Bean once
the springboot version is 2.1.5.RELEASE,JDK1.8
public class Users {
String name;
int age;
String gender;
public Users() {
}
public Users(String name, int age, String gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
}
#Component
public class UsersController implements ApplicationRunner {
#Autowired(required = false)
// #Resource
List<Users> users= Collections.emptyList();
#Override
public void run(ApplicationArguments args) {
System.out.println(users);
}
}
#RestController
public class HelloController implements
BeanDefinitionRegistryPostProcessor, ApplicationContextAware {
ApplicationContext applicationContext;
DefaultListableBeanFactory defaultListableBeanFactory;
Users users;
int i=0;
#RequestMapping("/hello1")
public String index1() {
return "hello";
}
#RequestMapping("/hello3")
public Users index3() {
UsersController controller =
applicationContext.getBean(UsersController.class);
controller.run(null);
return null;
}
#Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry
registry) throws BeansException {
}
#Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory
beanFactory) throws BeansException {
defaultListableBeanFactory= (DefaultListableBeanFactory)
beanFactory;
Users users=new Users("hello"+(i++),23,"fe");
this.users=users;
defaultListableBeanFactory.registerBeanDefinition(users.getName(),
BeanDefinitionBuilder.genericBeanDefinition(Users.class, () ->
users).getRawBeanDefinition());
}
#EventListener
public void onApplicationEvent(#NonNull EnvironmentChangeEvent
environmentChangeEvent) {
System.out.println("before
remove："+applicationContext.getBean(Users.class));
defaultListableBeanFactory.removeBeanDefinition(users.getName());
Users users=new Users("hello"+(i++),23,"fe");
this.users=users;
defaultListableBeanFactory.registerBeanDefinition(users.getName(),
BeanDefinitionBuilder.genericBeanDefinition(Users.class,
() -> users).getRawBeanDefinition());
System.out.println("after："+applicationContext.getBean(Users.class));
}
#Override
public void setApplicationContext(ApplicationContext
applicationContext) throws BeansException {
this.applicationContext=applicationContext;
}
}
pom.xml:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.8</version>
</dependency>
</dependencies>
only bootstrap.yml:
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: always
when start the application it will output [Users(name=hello0, age=23, gender=fe)],
and then visit the url by POST,
http://localhost:8080/actuator/refresh
it will output
before remove：Users(name=hello0, age=23, gender=fe)
after：Users(name=hello1, age=23, gender=fe)
then visit the url
http://localhost:8080/hello3
output
[Users(name=hello1, age=23, gender=fe)]
This is to be expected,if visit the url again
http://localhost:8080/actuator/refresh
output
before remove：Users(name=hello1, age=23, gender=fe)
after：Users(name=hello2, age=23, gender=fe)
This is also to be expected,but visit the url
http://localhost:8080/hello3
we hope it output
Users(name=hello2, age=23, gender=fe)
but it output
Users(name=hello1, age=23, gender=fe)
The output message is not what we expected.
If change #Autowired to #Resource in class UsersController, it should be normal.But it maybe null in real environment,the application will run fail if use #Resource
How can I solve this problem?
Thanks for your time.

Answer 1

#Resource
#Lazy
can star application properly.But it may cause error like
ERROR [main] com.Users - No qualifying bean of type 'java.util.List<com.Users>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#javax.annotation.Resource(shareable=true, lookup=, name=, description=, authenticationType=CONTAINER, type=class java.lang.Object, mappedName=), #org.springframework.context.annotation.Lazy(value=true)}

Answer 2

Please take a look at this part of the documentation in order to refresh your beans at runtime: https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html#refresh-scope