CODEWITHSUNDEEP
java
user1166635
user1166635

Reputation: 2801

How can I make parameterized method?

I have similar class for making Product factory:

package com.nda.generics;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import com.nda.generics.Sizeable.Size;

public class ProductFactory{

        private Collection<? extends Sizeable> sources;

        public ProductFactory(Collection<? extends Sizeable> sources) {
            this.sources=sources;
        }

        public void setSources(Collection<? extends Sizeable> sources) {
            this.sources=sources;
        }

        public Collection<Product> makeProductList() {

            Collection<Product> products=new ArrayList<Product>();

            for (Sizeable item:sources) {

                switch(item.getSize()) {

                    case BIG: products.add(new Sausage()); break;
                    case MIDDLE: products.add(new Feets()); break;
                    case LITTLE: products.add(new Conservative()); break;
                }
            }

            return products;
        }

        public class Conservative extends Product {

            private Conservative(){}
        }

        public class Feets extends Product {

            private Feets(){}
        }

        public class Sausage extends Product {

            private Sausage(){}
        }
    }

This factory makes list of products using size of animals. But I also need to parameterize method/class that I will set type of product, for exampe new Feets (using parameters of constructor). How can I do it? Thank you.

Upvotes: 0

Views: 129

Answers (2)

Dave
Dave

Reputation: 6179

I believe this is what you're looking for....

public <T extends Product> T getNewProduct(Class<T> productClass, String param1, int param2) {

   T product = productClass.newInstance();

   // Assuming your abstract Product class defines these setters
   product.setStringParam(param1);
   product.setIntParam(param2);

   return product;
 }

And then you can call like this....

// Assuming you want a Feet object....
Feet feet = productFactoryInstance.getNewProduct(Feet.class, "productParam1", productParam2);

Also, as a side note, you should make your ProductFacotry a singleton. You don't need more than one and it avoids a lot of other head aches, you can to this like so....

// Make ProductFacotry constructor private so you don't call "new" all over the place
private ProductFactory() {}

// Variable to hold your only instance of product factory (hence, singleton name...)
private static ProductFactory INSTANCE = null;

public static synchronized Get() {
  if(INSTANCE == null) {
    // You can call the constructor here, even though its private since you're
    // inside the same class
    INSTANCE = new ProductFactory();
  }

  return INSTANCE;
}

And then, whenever you want to use it to get a product, just do this....

Feet feet = ProductFactory.Get().getNewProduct(Feet.class, "productParam1", productParam2);

Upvotes: 1

rjmateus
rjmateus

Reputation: 26

In a method you can say that it takes a unknwn number of String parameters.

The Feed constructor may be something like this:

public class Feets extends Product {
    private Feets(String... args){
    }
}

The argument 'args' will be an array of String's.

Upvotes: 0

Related Questions