CODEWITHSUNDEEP
javaspring
Anuj Tomar
Anuj Tomar

Reputation: 3

How to Autowire a class at runtime in a method

Is it possible to Autowire fields in a dynamic class? I am getting a class name from the database and I want to autowire this class

Upvotes: 0

Views: 734

Answers (3)

Lino
Lino

Reputation: 19926

Short Answer

That's not possible. Spring needs to know what Beans there are for injecting them.

Long Answer

You could @Autowire every possible bean into a class and then cache them in a Map, where the Class represents the key, and the Object the value. See below simplified example:

public class MyClass{
     private final Map<Class<?>, Object> cache = new HashMap<>();

     @Autowired
     public MyClass(Service1 s1, Service2 s2){
         // registering the beans
         cache.put(Service1.class, s1);
         cache.put(Service2.class, s2);
     }

     public <T> T getService(String className) throws ClassNotFoundException{
         // getting the bean
         Class<?> clazz = Class.forName(className);
         return (T) cache.get(clazz);
     }
}

Upvotes: 1

bRiJeSh
bRiJeSh

Reputation: 810

You can try this: 

import javax.annotation.PostConstruct;

@Component
public class ApplicationContextAccessor {

private static ApplicationContextAccessor instance;

@Autowired
private ApplicationContext applicationContext;

public static  T getBean(Class clazz) {
    return instance.applicationContext.getBean(clazz);
}

@PostConstruct
private void registerInstance() {
    instance = this;
}

}

Read this post : https://www.helicaltech.com/uses-of-springs-applicationcontext-while-using-reflection/

Upvotes: 0

Oreste Viron
Oreste Viron

Reputation: 3805

Not sure it's a good idea, but you can inject a class like mentionned here : Injecting beans into a class outside the Spring managed context

Upvotes: 0

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