Updating value of particular keys in MultiKeyMap in Java

Question

I was trying to update the values of set of particular keys in MultiKeyMap in Java but not able to get how to do that.

Suppose I want to update (key1, key2, value1) same set of key with different value (key1, key2, value2).

If I simply perform put in MultiKeyMap then it create new row and doesn't update the value. replace() is also not working.

package com.example.demo;

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

import org.apache.commons.collections4.map.LinkedMap;
import org.apache.commons.collections4.map.MultiKeyMap;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        //SpringApplication.run(DemoApplication.class, args);

        List<Double> list11 = new ArrayList<Double>();
        list11.add((double) 3);
        list11.add((double) 5000);
        
        List<Double> list22 = new ArrayList<Double>();
        list22.add((double) 7);
        list22.add((double) 2000);
        
        MultiKeyMap<String, List<Double>> multiKeyMap = new MultiKeyMap<String, List<Double>>();
        multiKeyMap.put("sourcecode11", "basecode11", "productcode11", list11);
        multiKeyMap.put("sourcecode22", "basecode22", "productcode22", list22);
        
        String source = "sourcecode11";
        String base = "basecode11";
        String product = "productcode11";
        
        if (multiKeyMap.containsKey(source, base, product)) {
            List<Double> fees = multiKeyMap.get(source, base, product);
            Double count = fees.get(0);
            Double amount = fees.get(1);
            
            count +=1;
            amount+=500;
            List<Double> list33 = new ArrayList<Double>();
            list33.add(count);
            list33.add(amount);
            multiKeyMap.
            multiKeyMap.replace(source, base, product, list33);
        }
        

    }

}

Getting error at replace function

not applicable for the arguments (String, String, String, List<Double>)

Please provide solution for updating value in MultiKeyMap.

maven dependency :

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-collections4 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-collections4</artifactId>
    <version>4.4</version>
</dependency>

Answer 1

You can use put in order to replace (key1,key2,key3) with new value list. Your code run correct with this exemple

    List<Double> list11 = new ArrayList<>();
    List<Double> list22 = new ArrayList<>();
    list22.add((double) 7);
    list22.add((double) 2000);

    MultiKeyMap<String, List<Double>> multiKeyMap = new MultiKeyMap<>();
    multiKeyMap.put("sourcecode11", "basecode11", "productcode11", list11);
    multiKeyMap.put("sourcecode22", "basecode22", "productcode22", list22);

    String source = "sourcecode22";
    String base = "basecode22";
    String product = "productcode22";

    if (multiKeyMap.containsKey(source, base, product)) {
        List<Double> fees = multiKeyMap.get(source, base, product);
        System.out.println("before :" + multiKeyMap);
        Double count = fees.get(0);
        Double amount = fees.get(1);
        count += 1;
        amount += 500;
        List<Double> list33 = new ArrayList<>();
        list33.add(count);
        list33.add(amount);
        multiKeyMap.put(source, base, product, list33);
        System.out.println("after :" + multiKeyMap);
    }

Answer 2

This is confusing. You are working on the List 'fees' by getting 'count' and 'amount', incrementing them and then appending the incremented values as two new values to the List. Please tell us what's going on there.

It's also alarming that you seem to be treating a List as some sort of data-encapsulating class.