How do I use HashMap values from other class?-CodePudding

I need to access the values from one class within another class. In this example, I need to use the method .viewSupplies(); to list out all the values from the HashMap from the other class, Stock.java. Here's the code so far:

import java.util.HashMap;
import java.util.Map;

public class Employee {
    private int ID;
    private String name;
    private String phoneNumber;
    private String username;
    private String password;
    private Stock stock;
    HashMap<String, Integer> pro;

public Employee(int id, String n, String pho, String u, String pa, int sId){
    this.ID=id;
    this.name = n;
    this.phoneNumber=pho;
    this.username=u;
    this.password=pa;
    this.stock = new Stock(sId);
    this.pro =  stock.products;
    for(String k : stock.getProducts().keySet()){
        pro.put(k, stock.getProducts().get(k));
    }
}


public void viewSupplies(){
    for (String key : pro.keySet()){
        System.out.println(key   ": "   pro.get(key));
    }
}

}

And here's Stock.java:

import java.util.HashMap;
import java.util.Map;

public class Stock {
private int id;
public HashMap<String, Integer> products;

public Stock(int i){
    this.id = i;
    this.products = new HashMap<String, Integer>();
}

public void addProduct(String pName, int quantity){
    if(!products.containsKey(pName)){
        System.out.println("Error! Product not found.");
    }
    else{
        products.put(pName, quantity );
    }
}

public void deleteProduct(String pName) {
    if (!products.containsKey(pName)) {
        System.out.println("Error! Product not found.");
    } else {
        products.remove(pName);
    }
}

public void regProduct(String pName){
    products.put(pName, 0);
}

public void takeProduct(String pName, int quantity) {
    if(!products.containsKey(pName)){
        System.out.println("Error! Product not found.");
    }
    else {
        products.put(pName, products.get(pName) - quantity);
    }
}

public void listProducts(){
    for (Map.Entry<String, Integer> p : products.entrySet()){
        System.out.println(p.getKey()   ": "   p.getValue());
    }
}

public void findProduct(String pName){
    if(products.containsKey(pName)){
        System.out.println(pName   ": "   products.get(pName));
    }
    else{
        System.out.println("Error! Product not found.");
    }
}

public HashMap<String, Integer> getProducts(){
    return products;
}

As you can see, I do not know how to get keys and values from the public HashMap products from Stock in Employee.

CodePudding user response：

You already have the reference to the stock instance in the Employee class. You can get the stock's product and use it.

public void viewSupplies() {
    Map<String, Integer> products = stock.getProducts();
    for (String key : products.keySet()){
        System.out.println(key   ": "   products.get(key));
    }
}

With this, I don't think you would have the need to maintain a HashMap in the Employee class. Also, it is recommended to make the products field private in the Stock class.