CODEWITHSUNDEEP
javalistclassconstructorinstantiation
AKIWEB
AKIWEB

Reputation: 19612

Throws Exception while instantiating class

I have a very simple problem-

I have a class named DEClient whose constructor is like this-

public DEClient(List<DEKey> keys) {
    process(keys);
}

And DEKey class is like this-

public class DEKey {

    private String name;
    private String value;

    public DEKey(){
        name = null;
        value = null;
    }

    public DEKey(String name, String value){
        this.name  = name;
        this.value = value;
    }

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

    public String getValue() {
        return value;
    }
    public void setValue(String value) {
        this.value = value;
    }
}

Now I am trying to instantiate DEClient constructor. So for that I need to have List<DEKey>.

So what I did is I instantiated DEKey class like below using service.getKeys() (which will return String) and id as the value.

DEKey dk = new DEKey(service.getKeys(), id);

//The below line throws exception whenever I am running.
DEClient deClient = new DEClient((List<DEKey>) dk);

What wrong I am doing here?

Upvotes: 0

Views: 392

Answers (1)

A--C
A--C

Reputation: 36449

You need to first make a List, then add your key to that List. Casting like you have done is not the way to do it, since DEKey is not a List and casting into it will throw a ClassCastException.

DEKey dk = new DEKey(service.getKeys(), id);

List<DEKey> list = new ArrayList<DEKey>();
list.add (dk);

DEClient deClient = new DEClient(list);

Upvotes: 1

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