Spring Bean Scopes

Question

Can someone explain what the scopes are in Spring beans I\'ve always just used \'prototype\' but are there other parameters I can put in place of that?

Example of wh

Answer 1

A short example what is the difference between @Scope("singleton") (default) and @Scope("prototype"):

DAO class:

package com.example.demo;

public class Manager {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

Configuration:

@Configuration
public class AppConfiguration {
    @Bean
    @Scope("singleton")
    public Manager getManager(){
        return new Manager();
    }
}

and MainApp:

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
        context.scan("com.example.demo");
        context.refresh();

        Manager firstManager = context.getBean(Manager.class);
        firstManager.setName("Karol");

        Manager secondManager = context.getBean(Manager.class);
        System.out.println(secondManager.getName());
    }

}

In this example the result is: Karol even if we set this name only for firstManager object. It's because Spring IoC container created one instance of object. However when we change scope to @Scope("prototype") in Configuration class then result is: null because Spring IoC container creates a new bean instance of the object when request for that bean is made.