How to pass parameters dynamically to Spring beans

Question

I am new to Spring.

This is the code for bean registration:

<bean id="user" class="User_Imple"> </bean>
<bean id="userdeff" class="User"> </bean>

and this is my bean class:

public class User_Imple implements Master_interface {

    private int id;
    private User user; // here user is another class

    public User_Imple() {
        super();
    }

    public User_Imple(int id, User user) {
        super();
        this.id = id;
        this.user = user;
    }

    // some extra functions here....
}

and this is my main method to perform action:

public static void main(String arg[]) {

    ApplicationContext context = new ClassPathXmlApplicationContext("/bean.xml");
    Master_interface master = (Master_interface)context.getBean("user");

    // here is my some operations..
    int id = ...
    User user = ...

    // here is where i want to get a Spring bean
    User_Imple userImpl; //want Spring-managed bean created with above params
}

Now I want to call this constructor with parameters, and these parameters are generated dynamically in my main methods. This is what I mean by I want to pass dynamically – not statically, like declared in my bean.config file.

Answer 1

If i get you right, then the correct answer is to use #getBean(String beanName, Object... args) which will pass arguments to bean. I can show you, how it is done for java-based configuration, but you'll have to find how it is done for xml based configuration.

@Configuration
public class ApplicationConfiguration {

  @Bean
  @Scope("prototype") //As we want to create several beans with different args, right?
  String hello(String name) {
    return "Hello, " + name;
  }
}

//and later in your application

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfiguration.class);
String helloCat = (String) context.getBean("hello", "Cat");
String helloDog = (String) context.getBean("hello", "Dog");

Is this what are you looking for?

Upd. This answer gets too much upvotes and nobody looks at my comment. Even though it's a solution to problem, it is considered as spring anti-pattern and you shouldn't use it! There are several different ways to do things right using factory, lookup-method, etc..

Please use the following SO post as a point of reference: create beans at runtime