CODEWITHSUNDEEP
dependency-injectionjava-ee-6cdi
Srikrishna Kalavacharla
Srikrishna Kalavacharla

Reputation: 53

How to inject an instance of a class with a parameterized constructor using CDI (Java EE 6 only)

I'm new to CDI, tried searching for the usage, could not find anything and so posting the question. I'm trying to figure how I can inject an instance of a class with a parameterized constructor only using CDI. I'm not using Spring so, how it is done in spring does not help. Here is a sample I've created to show what's the issue. My @Inject will not work in this scenario. 

    public class A 
    {
        public A(boolean deliverFromLocalWarehouse)
        {
            if(deliverFromLocalWarehouse)
            {
                wareHouseId = new Integer(10); 
            }
            else 
            {
                wareHouseId = new Integer(100);
            }
        }

        public void deliver()
        {
            //get wareHouse address by Id and initiate delivery.   
        }

        private Integer wareHouseId = null;
    }

    public class B 
    {

        @Inject
        private A a;
    }

Thanks Srikrishna Kalavacharla

Upvotes: 3

Views: 7235

Answers (1)

meriton
meriton

Reputation: 70564

If the constructor parameter should come from a bean, I think you can simply annotate it:

public A(@Inject boolean localWarehouse) { ...

and inject it with

@Inject A a;

If you want two different instances of A (with different constructor arguments), you could subclass them:

public AForLocalWarehouse extends A {
    public AForLocalWarehouse() {
        super(true);
    }
}

and inject them with

@Inject AForLocalWarehouse a;

or use a producer method with qualifiers:

@Produces @LocalWarehouse
public A localWarehouse() { return new A(true); }

@Produces @RemoteWarehouse
public A remoteWarehouse() { return new A(false); }

and inject them with

@Inject @LocalWarehouse A a;
@Inject @RemoteWarehouse A a;

Upvotes: 2

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